Merge pull request #108 from NawfalMotii79/fix/adar1000-channel-rotation

fix(adar1000): correct 1-based channel indexing in setters (issue #90)
fix(adar1000): correct 1-based channel indexing in setters (issue #90 )
2026-04-18 06:00:52 +03:00 · 2026-04-18 06:39:07 +05:45 · 2026-04-18 02:02:07 +05:45 · 2026-04-17 19:31:31 +03:00 · 2026-04-17 22:12:26 +05:45 · 2026-04-17 17:21:59 +03:00
26 changed files with 5604 additions and 1258 deletions
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@@ -18,7 +18,7 @@ ADAR1000_AGC::ADAR1000_AGC()
    , min_gain(0)
    , max_gain(127)
    , holdoff_frames(4)
-    , enabled(true)
+    , enabled(false)
    , holdoff_counter(0)
    , last_saturated(false)
    , saturation_event_count(0)
@@ -20,18 +20,71 @@ static const struct {
    {ADAR_4_CS_3V3_GPIO_Port, ADAR_4_CS_3V3_Pin}  // ADAR1000 #4
 };

-// Vector Modulator lookup tables
+// ADAR1000 Vector Modulator lookup tables (128-state phase grid, 2.8125 deg step).
+//
+// Source: Analog Devices ADAR1000 datasheet Rev. B, Tables 13-16, page 34
+//   (7_Components Datasheets and Application notes/ADAR1000.pdf)
+// Cross-checked against the ADI Linux mainline driver (GPL-2.0, NOT vendored):
+//   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/
+//     drivers/iio/beamformer/adar1000.c  (adar1000_phase_values[])
+// The 128 byte values themselves are factual data from the datasheet and are
+// not subject to copyright; only the ADI driver code is GPL.
+//
+// Byte format (per datasheet):
+//   bit  [7:6] reserved (0)
+//   bit  [5]   polarity:  1 = positive lobe (sign(I) or sign(Q) >= 0)
+//                          0 = negative lobe
+//   bits [4:0] 5-bit unsigned magnitude (0..31)
+// At magnitude=0 the polarity bit is physically meaningless; the datasheet
+// uses POL=1 (e.g. VM_Q at 0 deg = 0x20, VM_I at 90 deg = 0x21).
+//
+// Index mapping is uniform: VM_I[k] / VM_Q[k] correspond to phase angle
+// k * 360/128 = k * 2.8125 degrees.  Callers index as VM_*[phase % 128].
 const uint8_t ADAR1000Manager::VM_I[128] = {
-    // ... (same as in your original file)
+    0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3E, 0x3E, 0x3D,  // [  0]   0.0000 deg
+    0x3D, 0x3C, 0x3C, 0x3B, 0x3A, 0x39, 0x38, 0x37,  // [  8]  22.5000 deg
+    0x36, 0x35, 0x34, 0x33, 0x32, 0x30, 0x2F, 0x2E,  // [ 16]  45.0000 deg
+    0x2C, 0x2B, 0x2A, 0x28, 0x27, 0x25, 0x24, 0x22,  // [ 24]  67.5000 deg
+    0x21, 0x01, 0x03, 0x04, 0x06, 0x07, 0x08, 0x0A,  // [ 32]  90.0000 deg
+    0x0B, 0x0D, 0x0E, 0x0F, 0x11, 0x12, 0x13, 0x14,  // [ 40] 112.5000 deg
+    0x16, 0x17, 0x18, 0x19, 0x19, 0x1A, 0x1B, 0x1C,  // [ 48] 135.0000 deg
+    0x1C, 0x1D, 0x1E, 0x1E, 0x1E, 0x1F, 0x1F, 0x1F,  // [ 56] 157.5000 deg
+    0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1E, 0x1E, 0x1D,  // [ 64] 180.0000 deg
+    0x1D, 0x1C, 0x1C, 0x1B, 0x1A, 0x19, 0x18, 0x17,  // [ 72] 202.5000 deg
+    0x16, 0x15, 0x14, 0x13, 0x12, 0x10, 0x0F, 0x0E,  // [ 80] 225.0000 deg
+    0x0C, 0x0B, 0x0A, 0x08, 0x07, 0x05, 0x04, 0x02,  // [ 88] 247.5000 deg
+    0x01, 0x21, 0x23, 0x24, 0x26, 0x27, 0x28, 0x2A,  // [ 96] 270.0000 deg
+    0x2B, 0x2D, 0x2E, 0x2F, 0x31, 0x32, 0x33, 0x34,  // [104] 292.5000 deg
+    0x36, 0x37, 0x38, 0x39, 0x39, 0x3A, 0x3B, 0x3C,  // [112] 315.0000 deg
+    0x3C, 0x3D, 0x3E, 0x3E, 0x3E, 0x3F, 0x3F, 0x3F,  // [120] 337.5000 deg
 };

 const uint8_t ADAR1000Manager::VM_Q[128] = {
-    // ... (same as in your original file)
+    0x20, 0x21, 0x23, 0x24, 0x26, 0x27, 0x28, 0x2A,  // [  0]   0.0000 deg
+    0x2B, 0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x33, 0x34,  // [  8]  22.5000 deg
+    0x35, 0x36, 0x37, 0x38, 0x38, 0x39, 0x3A, 0x3A,  // [ 16]  45.0000 deg
+    0x3B, 0x3C, 0x3C, 0x3C, 0x3D, 0x3D, 0x3D, 0x3D,  // [ 24]  67.5000 deg
+    0x3D, 0x3D, 0x3D, 0x3D, 0x3D, 0x3C, 0x3C, 0x3C,  // [ 32]  90.0000 deg
+    0x3B, 0x3A, 0x3A, 0x39, 0x38, 0x38, 0x37, 0x36,  // [ 40] 112.5000 deg
+    0x35, 0x34, 0x33, 0x31, 0x30, 0x2F, 0x2E, 0x2D,  // [ 48] 135.0000 deg
+    0x2B, 0x2A, 0x28, 0x27, 0x26, 0x24, 0x23, 0x21,  // [ 56] 157.5000 deg
+    0x20, 0x01, 0x03, 0x04, 0x06, 0x07, 0x08, 0x0A,  // [ 64] 180.0000 deg
+    0x0B, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x13, 0x14,  // [ 72] 202.5000 deg
+    0x15, 0x16, 0x17, 0x18, 0x18, 0x19, 0x1A, 0x1A,  // [ 80] 225.0000 deg
+    0x1B, 0x1C, 0x1C, 0x1C, 0x1D, 0x1D, 0x1D, 0x1D,  // [ 88] 247.5000 deg
+    0x1D, 0x1D, 0x1D, 0x1D, 0x1D, 0x1C, 0x1C, 0x1C,  // [ 96] 270.0000 deg
+    0x1B, 0x1A, 0x1A, 0x19, 0x18, 0x18, 0x17, 0x16,  // [104] 292.5000 deg
+    0x15, 0x14, 0x13, 0x11, 0x10, 0x0F, 0x0E, 0x0D,  // [112] 315.0000 deg
+    0x0B, 0x0A, 0x08, 0x07, 0x06, 0x04, 0x03, 0x01,  // [120] 337.5000 deg
 };

-const uint8_t ADAR1000Manager::VM_GAIN[128] = {
-    // ... (same as in your original file)
-};
+// NOTE: a VM_GAIN[128] table previously existed here as a placeholder but was
+// never populated and never read.  The ADAR1000 vector modulator has no
+// separate gain register: phase-state magnitude is encoded directly in
+// bits [4:0] of the VM_I/VM_Q bytes above.  Per-channel VGA gain is a
+// distinct register (CHx_RX_GAIN at 0x10-0x13, CHx_TX_GAIN at 0x1C-0x1F)
+// written with the user-supplied byte directly by adarSetRxVgaGain() /
+// adarSetTxVgaGain().  Do not reintroduce a VM_GAIN[] array.

 ADAR1000Manager::ADAR1000Manager() {
    for (int i = 0; i < 4; ++i) {
@@ -815,11 +868,22 @@ void ADAR1000Manager::adarSetRamBypass(uint8_t deviceIndex, uint8_t broadcast) {
 }

 void ADAR1000Manager::adarSetRxPhase(uint8_t deviceIndex, uint8_t channel, uint8_t phase, uint8_t broadcast) {
+    // channel is 1-based (CH1..CH4) per API contract documented in
+    // ADAR1000_AGC.cpp and matching ADI datasheet terminology.
+    // Reject out-of-range early so a stale 0-based caller does not
+    // silently wrap to ((0-1) & 0x03) == 3 and write to CH4.
+    // See issue #90.
+    if (channel < 1 || channel > 4) {
+        DIAG("BF", "adarSetRxPhase: channel %u out of range [1..4], ignored", channel);
+        return;
+    }
    uint8_t i_val = VM_I[phase % 128];
    uint8_t q_val = VM_Q[phase % 128];

-    uint32_t mem_addr_i = REG_CH1_RX_PHS_I + (channel & 0x03) * 2;
-    uint32_t mem_addr_q = REG_CH1_RX_PHS_Q + (channel & 0x03) * 2;
+    // Subtract 1 to convert 1-based channel to 0-based register offset
+    // before masking. See issue #90.
+    uint32_t mem_addr_i = REG_CH1_RX_PHS_I + ((channel - 1) & 0x03) * 2;
+    uint32_t mem_addr_q = REG_CH1_RX_PHS_Q + ((channel - 1) & 0x03) * 2;

    adarWrite(deviceIndex, mem_addr_i, i_val, broadcast);
    adarWrite(deviceIndex, mem_addr_q, q_val, broadcast);
@@ -827,11 +891,16 @@ void ADAR1000Manager::adarSetRxPhase(uint8_t deviceIndex, uint8_t channel, uint8
 }

 void ADAR1000Manager::adarSetTxPhase(uint8_t deviceIndex, uint8_t channel, uint8_t phase, uint8_t broadcast) {
+    // channel is 1-based (CH1..CH4). See issue #90.
+    if (channel < 1 || channel > 4) {
+        DIAG("BF", "adarSetTxPhase: channel %u out of range [1..4], ignored", channel);
+        return;
+    }
    uint8_t i_val = VM_I[phase % 128];
    uint8_t q_val = VM_Q[phase % 128];

-    uint32_t mem_addr_i = REG_CH1_TX_PHS_I + (channel & 0x03) * 2;
-    uint32_t mem_addr_q = REG_CH1_TX_PHS_Q + (channel & 0x03) * 2;
+    uint32_t mem_addr_i = REG_CH1_TX_PHS_I + ((channel - 1) & 0x03) * 2;
+    uint32_t mem_addr_q = REG_CH1_TX_PHS_Q + ((channel - 1) & 0x03) * 2;

    adarWrite(deviceIndex, mem_addr_i, i_val, broadcast);
    adarWrite(deviceIndex, mem_addr_q, q_val, broadcast);
@@ -839,13 +908,23 @@ void ADAR1000Manager::adarSetTxPhase(uint8_t deviceIndex, uint8_t channel, uint8
 }

 void ADAR1000Manager::adarSetRxVgaGain(uint8_t deviceIndex, uint8_t channel, uint8_t gain, uint8_t broadcast) {
-    uint32_t mem_addr = REG_CH1_RX_GAIN + (channel & 0x03);
+    // channel is 1-based (CH1..CH4). See issue #90.
+    if (channel < 1 || channel > 4) {
+        DIAG("BF", "adarSetRxVgaGain: channel %u out of range [1..4], ignored", channel);
+        return;
+    }
+    uint32_t mem_addr = REG_CH1_RX_GAIN + ((channel - 1) & 0x03);
    adarWrite(deviceIndex, mem_addr, gain, broadcast);
    adarWrite(deviceIndex, REG_LOAD_WORKING, 0x1, broadcast);
 }

 void ADAR1000Manager::adarSetTxVgaGain(uint8_t deviceIndex, uint8_t channel, uint8_t gain, uint8_t broadcast) {
-    uint32_t mem_addr = REG_CH1_TX_GAIN + (channel & 0x03);
+    // channel is 1-based (CH1..CH4). See issue #90.
+    if (channel < 1 || channel > 4) {
+        DIAG("BF", "adarSetTxVgaGain: channel %u out of range [1..4], ignored", channel);
+        return;
+    }
+    uint32_t mem_addr = REG_CH1_TX_GAIN + ((channel - 1) & 0x03);
    adarWrite(deviceIndex, mem_addr, gain, broadcast);
    adarWrite(deviceIndex, REG_LOAD_WORKING, LD_WRK_REGS_LDTX_OVERRIDE, broadcast);
 }
@@ -116,10 +116,12 @@ public:
    bool beam_sweeping_active_ = false;
    uint32_t last_beam_update_time_ = 0;

-    // Lookup tables
-    static const uint8_t VM_I[128];
+    // Vector Modulator lookup tables (see ADAR1000_Manager.cpp for provenance).
+    // Indexed as VM_*[phase % 128] on a uniform 2.8125 deg grid.
+    // No VM_GAIN[] table exists: VM magnitude is bits [4:0] of the I/Q bytes
+    // themselves; per-channel VGA gain uses a separate register.
+    static const uint8_t VM_I[128];
    static const uint8_t VM_Q[128];
-    static const uint8_t VM_GAIN[128];

    // Named defaults for the ADTR1107 and ADAR1000 power sequence.
    static constexpr uint8_t kDefaultTxVgaGain = 0x7F;
@@ -1,693 +0,0 @@
-/**
- * MIT License
- * 
- * Copyright (c) 2020 Jimmy Pentz
- *
- * Reach me at: github.com/jgpentz, jpentz1(at)gmail.com
- * 
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sells
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- * 
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- * 
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-/* ADAR1000 4-Channel, X Band and Ku Band Beamformer */
-// ----------------------------------------------------------------------------
-// Includes
-// ----------------------------------------------------------------------------
-#include "main.h"
-#include "stm32f7xx_hal.h"
-#include "stm32f7xx_hal_spi.h"
-#include "stm32f7xx_hal_gpio.h"
-#include "adar1000.h"
-
-
-// ----------------------------------------------------------------------------
-// Preprocessor Definitions and Constants
-// ----------------------------------------------------------------------------
-// VM_GAIN is 15 dB of gain in 128 steps. ~0.12 dB per step.
-// A 15 dB attenuator can be applied on top of these values.
-const uint8_t VM_GAIN[128] = {
-	0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
-	0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
-	0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
-	0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
-	0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
-	0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
-	0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
-	0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
-};
-
-// VM_I and VM_Q are the settings for the vector modulator. 128 steps in 360 degrees. ~2.813 degrees per step.
-const uint8_t VM_I[128] = {
-	0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3E, 0x3E, 0x3D, 0x3D, 0x3C, 0x3C, 0x3B, 0x3A, 0x39, 0x38, 0x37,
-	0x36, 0x35, 0x34, 0x33, 0x32, 0x30, 0x2F, 0x2E, 0x2C, 0x2B, 0x2A, 0x28, 0x27, 0x25, 0x24, 0x22,
-	0x21, 0x01, 0x03, 0x04, 0x06, 0x07, 0x08, 0x0A, 0x0B, 0x0D, 0x0E, 0x0F, 0x11, 0x12, 0x13, 0x14,
-	0x16, 0x17, 0x18, 0x19, 0x19, 0x1A, 0x1B, 0x1C, 0x1C, 0x1D, 0x1E, 0x1E, 0x1E, 0x1F, 0x1F, 0x1F,
-	0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1E, 0x1E, 0x1D, 0x1D, 0x1C, 0x1C, 0x1B, 0x1A, 0x19, 0x18, 0x17,
-	0x16, 0x15, 0x14, 0x13, 0x12, 0x10, 0x0F, 0x0E, 0x0C, 0x0B, 0x0A, 0x08, 0x07, 0x05, 0x04, 0x02,
-	0x01, 0x21, 0x23, 0x24, 0x26, 0x27, 0x28, 0x2A, 0x2B, 0x2D, 0x2E, 0x2F, 0x31, 0x32, 0x33, 0x34,
-	0x36, 0x37, 0x38, 0x39, 0x39, 0x3A, 0x3B, 0x3C, 0x3C, 0x3D, 0x3E, 0x3E, 0x3E, 0x3F, 0x3F, 0x3F,
-};
-
-const uint8_t VM_Q[128] = {
-	0x20, 0x21, 0x23, 0x24, 0x26, 0x27, 0x28, 0x2A, 0x2B, 0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x33, 0x34,
-	0x35, 0x36, 0x37, 0x38, 0x38, 0x39, 0x3A, 0x3A, 0x3B, 0x3C, 0x3C, 0x3C, 0x3D, 0x3D, 0x3D, 0x3D,
-	0x3D, 0x3D, 0x3D, 0x3D, 0x3D, 0x3C, 0x3C, 0x3C, 0x3B, 0x3A, 0x3A, 0x39, 0x38, 0x38, 0x37, 0x36,
-	0x35, 0x34, 0x33, 0x31, 0x30, 0x2F, 0x2E, 0x2D, 0x2B, 0x2A, 0x28, 0x27, 0x26, 0x24, 0x23, 0x21,
-	0x20, 0x01, 0x03, 0x04, 0x06, 0x07, 0x08, 0x0A, 0x0B, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x13, 0x14,
-	0x15, 0x16, 0x17, 0x18, 0x18, 0x19, 0x1A, 0x1A, 0x1B, 0x1C, 0x1C, 0x1C, 0x1D, 0x1D, 0x1D, 0x1D,
-	0x1D, 0x1D, 0x1D, 0x1D, 0x1D, 0x1C, 0x1C, 0x1C, 0x1B, 0x1A, 0x1A, 0x19, 0x18, 0x18, 0x17, 0x16,
-	0x15, 0x14, 0x13, 0x11, 0x10, 0x0F, 0x0E, 0x0D, 0x0B, 0x0A, 0x08, 0x07, 0x06, 0x04, 0x03, 0x01,
-};
-
-
-// ----------------------------------------------------------------------------
-// Function Definitions
-// ----------------------------------------------------------------------------
-/**
- * @brief	Initialize the ADC on the ADAR by setting the ADC with a 2 MHz clk, 
- *			and then enable it.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param 	broadcast	Send the message as a broadcast to all ADARs in the SPI chain
- *						if this set to BROADCAST_ON.
- *
- * @warning	This is setup to only read temperature sensor data, not the power detectors.
- */
-void Adar_AdcInit(const AdarDevice * p_adar, uint8_t broadcast)
-{
-	uint8_t data;
-
-	data = ADAR1000_ADC_2MHZ_CLK | ADAR1000_ADC_EN;
-
-	Adar_Write(p_adar, REG_ADC_CONTROL, data, broadcast);
-}
-
-
-/**
- * @brief	Read a byte of data from the ADAR.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param 	broadcast	Send the message as a broadcast to all ADARs in the SPI chain
- *						if this set to BROADCAST_ON.
- *
- * @return	Returns a byte of data that has been converted from the temperature sensor.
- *
- * @warning	This is setup to only read temperature sensor data, not the power detectors.
- */
-uint8_t Adar_AdcRead(const AdarDevice * p_adar, uint8_t broadcast)
-{
-	uint8_t data;
-
-    // Start the ADC conversion
-	Adar_Write(p_adar, REG_ADC_CONTROL, ADAR1000_ADC_ST_CONV, broadcast);
-
-    // This is blocking for now... wait until data is converted, then read it
-	while (!(Adar_Read(p_adar, REG_ADC_CONTROL) & 0x01))
-	{
-	}
-
-	data = Adar_Read(p_adar, REG_ADC_OUT);
-
-	return(data);
-}
-
-
-/**
- * @brief	Requests the device info from a specific ADAR and stores it in the
- *			provided AdarDeviceInfo struct.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param   info[out]	Struct that contains the device info fields.
- *
- * @return	Returns ADAR_ERROR_NOERROR if information was successfully received and stored in the struct.
- */
-uint8_t Adar_GetDeviceInfo(const AdarDevice * p_adar, AdarDeviceInfo * info)
-{
-	*((uint8_t *)info) = Adar_Read(p_adar, 0x002);
-	info->chip_type = Adar_Read(p_adar, 0x003);
-	info->product_id = ((uint16_t)Adar_Read(p_adar, 0x004)) << 8;
-	info->product_id |= ((uint16_t)Adar_Read(p_adar, 0x005)) & 0x00ff;
-	info->scratchpad = Adar_Read(p_adar, 0x00A);
-	info->spi_rev = Adar_Read(p_adar, 0x00B);
-	info->vendor_id = ((uint16_t)Adar_Read(p_adar, 0x00C)) << 8;
-	info->vendor_id |= ((uint16_t)Adar_Read(p_adar, 0x00D)) & 0x00ff;
-	info->rev_id = Adar_Read(p_adar, 0x045);
-
-	return(ADAR_ERROR_NOERROR);
-}
-
-
-/**
- * @brief	Read the data that is stored in a single ADAR register.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param	mem_addr	Memory address of the register you wish to read from.
- *
- * @return	Returns the byte of data that is stored in the desired register.
- *
- * @warning	This function will clear ADDR_ASCN bits.
- * @warning The ADAR does not allow for block reads.
- */
-uint8_t Adar_Read(const AdarDevice * p_adar, uint32_t mem_addr)
-{
-	uint8_t instruction[3];
-
-    // Set SDO active
-	Adar_Write(p_adar, REG_INTERFACE_CONFIG_A, INTERFACE_CONFIG_A_SDO_ACTIVE, 0);
-
-	instruction[0] = 0x80 | ((p_adar->dev_addr & 0x03) << 5);
-	instruction[0] |= ((0xff00 & mem_addr) >> 8);
-	instruction[1] = (0xff & mem_addr);
-	instruction[2] = 0x00;
-
-	p_adar->Transfer(instruction, p_adar->p_rx_buffer, ADAR1000_RD_SIZE);
-
-    // Set SDO Inactive
-	Adar_Write(p_adar, REG_INTERFACE_CONFIG_A, 0, 0);
-
-	return(p_adar->p_rx_buffer[2]);
-}
-
-
-/**
- * @brief	Block memory write to an ADAR device.
- *
- * @pre		ADDR_ASCN bits in register zero must be set!
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param	mem_addr  	Memory address of the register you wish to read from.
- * @param	p_data    	Pointer to block of data to transfer (must have two unused bytes preceding the data for instruction).
- * @param	size      	Size of data in bytes, including the two additional leading bytes.
- *
- * @warning First two bytes of data will be corrupted if you do not provide two unused leading bytes!
- */
-void Adar_ReadBlock(const AdarDevice * p_adar, uint16_t mem_addr, uint8_t * p_data, uint32_t size)
-{
-    // Set SDO active
-	Adar_Write(p_adar, REG_INTERFACE_CONFIG_A, INTERFACE_CONFIG_A_SDO_ACTIVE | INTERFACE_CONFIG_A_ADDR_ASCN, 0);
-
-    // Prepare command
-	p_data[0] = 0x80 | ((p_adar->dev_addr & 0x03) << 5);
-	p_data[0] |= ((mem_addr) >> 8) & 0x1F;
-	p_data[1] = (0xFF & mem_addr);
-
-    // Start the transfer
-	p_adar->Transfer(p_data, p_data, size);
-
-	Adar_Write(p_adar, REG_INTERFACE_CONFIG_A, 0, 0);
-    // Return nothing since we assume this is non-blocking and won't wait around
-}
-
-
-/**
- * @brief	Sets the Rx/Tx bias currents for the LNA, VM, and VGA to be in either
- *			low power setting or nominal setting.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param	p_bias[in]	An AdarBiasCurrents struct filled with bias settings
- *						as seen in the datasheet Table 6. SPI Settings for 
- *						Different Power	Modules
- * @param 	broadcast	Send the message as a broadcast to all ADARs in the SPI chain
- *						if this set to BROADCAST_ON.
- *
- * @return	Returns ADAR_ERR_NOERROR if the bias currents were set 
- */
-uint8_t Adar_SetBiasCurrents(const AdarDevice * p_adar, AdarBiasCurrents * p_bias, uint8_t broadcast)
-{
-	uint8_t bias = 0;
-
-    // RX LNA/VGA/VM bias
-	bias = (p_bias->rx_lna & 0x0f);
-	Adar_Write(p_adar, REG_BIAS_CURRENT_RX_LNA, bias, broadcast); // RX LNA bias
-	bias = (p_bias->rx_vga & 0x07 << 3) | (p_bias->rx_vm & 0x07);
-	Adar_Write(p_adar, REG_BIAS_CURRENT_RX, bias, broadcast);     // RX VM/VGA bias
-
-    // TX VGA/VM/DRV bias
-	bias = (p_bias->tx_vga & 0x07 << 3) | (p_bias->tx_vm & 0x07);
-	Adar_Write(p_adar, REG_BIAS_CURRENT_TX, bias, broadcast);     // TX VM/VGA bias
-	bias = (p_bias->tx_drv & 0x07);
-	Adar_Write(p_adar, REG_BIAS_CURRENT_TX_DRV, bias, broadcast); // TX DRV bias
-	
-	return(ADAR_ERROR_NOERROR);
-}
-
-
-/**
- * @brief	Set the bias ON and bias OFF voltages for the four PA's and one LNA.
- *
- * @pre		This will set all 5 bias ON values and all 5 bias OFF values at once.
- * 			To enable these bias values, please see the data sheet and ensure that the BIAS_CTRL,
- * 			LNA_BIAS_OUT_EN, TR_SOURCE, TX_EN, RX_EN, TR (input to chip), and PA_ON (input to chip)
- * 			bits have all been properly set.
- *
- * @param	p_adar[in]		Adar pointer Which specifies the device and what function 
- *							to use for SPI transfer.
- * @param 	bias_on_voltage   Array that contains the bias ON voltages.
- * @param 	bias_off_voltage  Array that contains the bias OFF voltages.
- *
- * @return	Returns ADAR_ERR_NOERROR if the bias currents were set 
- */
-uint8_t Adar_SetBiasVoltages(const AdarDevice * p_adar, uint8_t bias_on_voltage[5], uint8_t bias_off_voltage[5])
-{
-	Adar_SetBit(p_adar, 0x30, 6, BROADCAST_OFF);
-	Adar_SetBit(p_adar, 0x31, 2, BROADCAST_OFF);
-	Adar_SetBit(p_adar, 0x38, 5, BROADCAST_OFF);
-	Adar_Write(p_adar, REG_PA_CH1_BIAS_ON,bias_on_voltage[0], BROADCAST_OFF);
-	Adar_Write(p_adar, REG_PA_CH2_BIAS_ON,bias_on_voltage[1], BROADCAST_OFF);
-	Adar_Write(p_adar, REG_PA_CH3_BIAS_ON,bias_on_voltage[2], BROADCAST_OFF);
-	Adar_Write(p_adar, REG_PA_CH4_BIAS_ON,bias_on_voltage[3], BROADCAST_OFF);
-
-	Adar_Write(p_adar, REG_PA_CH1_BIAS_OFF,bias_off_voltage[0], BROADCAST_OFF);
-	Adar_Write(p_adar, REG_PA_CH2_BIAS_OFF,bias_off_voltage[1], BROADCAST_OFF);
-	Adar_Write(p_adar, REG_PA_CH3_BIAS_OFF,bias_off_voltage[2], BROADCAST_OFF);
-	Adar_Write(p_adar, REG_PA_CH4_BIAS_OFF,bias_off_voltage[3], BROADCAST_OFF);
-
-	Adar_SetBit(p_adar, 0x30, 4, BROADCAST_OFF);
-	Adar_SetBit(p_adar, 0x30, 6, BROADCAST_OFF);
-	Adar_SetBit(p_adar, 0x31, 2, BROADCAST_OFF);
-	Adar_SetBit(p_adar, 0x38, 5, BROADCAST_OFF);
-	Adar_Write(p_adar, REG_LNA_BIAS_ON,bias_on_voltage[4], BROADCAST_OFF);
-	Adar_Write(p_adar, REG_LNA_BIAS_OFF,bias_off_voltage[4], BROADCAST_OFF);
-
-	Adar_ResetBit(p_adar, 0x30, 7, BROADCAST_OFF);
-	Adar_SetBit(p_adar, 0x31, 2, BROADCAST_OFF);
-	Adar_SetBit(p_adar, 0x31, 4, BROADCAST_OFF);
-	Adar_SetBit(p_adar, 0x31, 7, BROADCAST_OFF);
-	
-	return(ADAR_ERROR_NOERROR);
-}
-
-
-/**
- * @brief	Setup the ADAR to use settings that are transferred over SPI.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param 	broadcast	Send the message as a broadcast to all ADARs in the SPI chain
- *						if this set to BROADCAST_ON.
- *
- * @return	Returns ADAR_ERR_NOERROR if the bias currents were set 
- */
-uint8_t Adar_SetRamBypass(const AdarDevice * p_adar, uint8_t broadcast)
-{
-	uint8_t data;
-
-	data = (MEM_CTRL_BIAS_RAM_BYPASS | MEM_CTRL_BEAM_RAM_BYPASS);
-
-	Adar_Write(p_adar, REG_MEM_CTL, data, broadcast);
-
-	return(ADAR_ERROR_NOERROR);
-}
-
-
-/**
- * @brief	Set the VGA gain value of a Receive channel in dB.
- *
- * @param	p_adar[in]		Adar pointer Which specifies the device and what function 
- *							to use for SPI transfer.
- * @param 	channel			Channel in which to set the gain (1-4).
- * @param 	vga_gain_db		Gain to be applied to the channel, ranging from 0 - 30 dB. 
- *							(Intended operation >16 dB).
- * @param 	broadcast	Send the message as a broadcast to all ADARs in the SPI chain
- *						if this set to BROADCAST_ON.
- *
- * @return 	Returns ADAR_ERROR_NOERROR if the gain was successfully set. 
- * 					ADAR_ERROR_FAILED if an invalid channel was selected.
- *
- * @warning 0 dB or 15 dB step attenuator may also be turned on, which is why intended operation is >16 dB.
- */
-uint8_t Adar_SetRxVgaGain(const AdarDevice * p_adar, uint8_t channel, uint8_t vga_gain_db, uint8_t broadcast)
-{
-	uint8_t	 vga_gain_bits = (uint8_t)(255*vga_gain_db/16);
-	uint32_t mem_addr = 0;
-
-	if((channel == 0) || (channel > 4))
-	{
-		return(ADAR_ERROR_FAILED);
-	}
-
-	mem_addr = REG_CH1_RX_GAIN + (channel & 0x03);
-
-    // Set gain
-	Adar_Write(p_adar, mem_addr, vga_gain_bits, broadcast);
-
-    // Load the new setting
-	Adar_Write(p_adar, REG_LOAD_WORKING, 0x1, broadcast);
-
-	return(ADAR_ERROR_NOERROR);
-}
-
-
-/**
- * @brief	Set the phase of a given receive channel using the I/Q vector modulator.
- *
- * @pre		According to the given @param phase, this sets the polarity (bit 5) and gain (bits 4-0)
- * 			of the @param channel, and then loads them into the working register.
- * 			A vector modulator I/Q look-up table has been provided at the beginning of this library.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param	channel   	Channel in which to set the gain (1-4).
- * @param	phase     	Byte that is used to set the polarity (bit 5) and gain (bits 4-0).
- * @param 	broadcast	Send the message as a broadcast to all ADARs in the SPI chain
- *						if this set to BROADCAST_ON.
- *
- * @return 	Returns ADAR_ERROR_NOERROR if the phase was successfully set. 
- * 					ADAR_ERROR_FAILED if an invalid channel was selected.
- *
- * @note    To obtain your phase:
- *          phase = degrees * 128;
- *          phase /= 360;
- */
-uint8_t Adar_SetRxPhase(const AdarDevice * p_adar, uint8_t channel, uint8_t phase, uint8_t broadcast)
-{
-	uint8_t	 i_val = 0;
-	uint8_t	 q_val = 0;
-	uint32_t mem_addr_i, mem_addr_q;
-
-	if((channel == 0) || (channel > 4))
-	{
-		return(ADAR_ERROR_FAILED);
-	}
-
-	//phase = phase % 128;
-	i_val = VM_I[phase];
-	q_val = VM_Q[phase];
-
-	mem_addr_i = REG_CH1_RX_PHS_I + (channel & 0x03) * 2;
-	mem_addr_q = REG_CH1_RX_PHS_Q + (channel & 0x03) * 2;
-
-	Adar_Write(p_adar, mem_addr_i, i_val, broadcast);
-	Adar_Write(p_adar, mem_addr_q, q_val, broadcast);
-	Adar_Write(p_adar, REG_LOAD_WORKING, 0x1, broadcast);
-
-	return(ADAR_ERROR_NOERROR);
-}
-
-
-/**
- * @brief	Set the VGA gain value of a Tx channel in dB.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param 	broadcast	Send the message as a broadcast to all ADARs in the SPI chain
- *						if this set to BROADCAST_ON.
- *
- * @return 	Returns ADAR_ERROR_NOERROR if the bias was successfully set. 
- * 					ADAR_ERROR_FAILED if an invalid channel was selected.
- *
- * @warning 0 dB or 15 dB step attenuator may also be turned on, which is why intended operation is >16 dB.
- */
-uint8_t Adar_SetTxBias(const AdarDevice * p_adar, uint8_t broadcast)
-{
-	uint8_t	 vga_bias_bits;
-	uint8_t	 drv_bias_bits;
-	uint32_t mem_vga_bias;
-	uint32_t mem_drv_bias;
-
-	mem_vga_bias = REG_BIAS_CURRENT_TX;
-	mem_drv_bias = REG_BIAS_CURRENT_TX_DRV;
-
-    // Set bias to nom
-	vga_bias_bits = 0x2D;
-	drv_bias_bits = 0x06;
-
-    // Set bias
-	Adar_Write(p_adar, mem_vga_bias, vga_bias_bits, broadcast);
-    // Set bias
-	Adar_Write(p_adar, mem_drv_bias, drv_bias_bits, broadcast);
-
-    // Load the new setting
-	Adar_Write(p_adar, REG_LOAD_WORKING, 0x2, broadcast);
-
-	return(ADAR_ERROR_NOERROR);
-}
-
-
-/**
- * @brief	Set the VGA gain value of a Tx channel.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param 	channel     Tx channel in which to set the gain, ranging from 1 - 4.
- * @param 	gain   		Gain to be applied to the channel, ranging from 0 - 127,
- *						plus the MSb 15dB attenuator (Intended operation >16 dB).
- * @param 	broadcast	Send the message as a broadcast to all ADARs in the SPI chain
- *						if this set to BROADCAST_ON.
- *
- * @return 	Returns ADAR_ERROR_NOERROR if the gain was successfully set. 
- * 					ADAR_ERROR_FAILED if an invalid channel was selected.
- *
- * @warning 0 dB or 15 dB step attenuator may also be turned on, which is why intended operation is >16 dB.
- */
-uint8_t Adar_SetTxVgaGain(const AdarDevice * p_adar, uint8_t channel, uint8_t gain, uint8_t broadcast)
-{
-	uint32_t mem_addr;
-	
-	if((channel == 0) || (channel > 4))
-	{
-		return(ADAR_ERROR_FAILED);
-	}
-
-	mem_addr = REG_CH1_TX_GAIN + (channel & 0x03);
-
-    // Set gain
-	Adar_Write(p_adar, mem_addr, gain, broadcast);
-
-    // Load the new setting
-	Adar_Write(p_adar, REG_LOAD_WORKING, LD_WRK_REGS_LDTX_OVERRIDE, broadcast);
-
-	return(ADAR_ERROR_NOERROR);
-}
-
-
-/**
- * @brief 	Set the phase of a given transmit channel using the I/Q vector modulator.
- *
- * @pre		According to the given @param phase, this sets the polarity (bit 5) and gain (bits 4-0)
- * 			of the @param channel, and then loads them into the working register.
- * 			A vector modulator I/Q look-up table has been provided at the beginning of this library.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param 	channel   	Channel in which to set the gain (1-4).
- * @param 	phase     	Byte that is used to set the polarity (bit 5) and gain (bits 4-0).
- * @param 	broadcast	Send the message as a broadcast to all ADARs in the SPI chain
- *						if this set to BROADCAST_ON.
- *
- * @return 	Returns ADAR_ERROR_NOERROR if the phase was successfully set. 
- * 					ADAR_ERROR_FAILED if an invalid channel was selected.
- *
- * @note    To obtain your phase:
- *          phase = degrees * 128;
- *          phase /= 360;
- */
-uint8_t Adar_SetTxPhase(const AdarDevice * p_adar, uint8_t channel, uint8_t phase, uint8_t broadcast)
-{
-	uint8_t	 i_val = 0;
-	uint8_t	 q_val = 0;
-	uint32_t mem_addr_i, mem_addr_q;
-
-	if((channel == 0) || (channel > 4))
-	{
-		return(ADAR_ERROR_FAILED);
-	}
-
-	//phase = phase % 128;
-	i_val = VM_I[phase];
-	q_val = VM_Q[phase];
-
-	mem_addr_i = REG_CH1_TX_PHS_I + (channel & 0x03) * 2;
-	mem_addr_q = REG_CH1_TX_PHS_Q + (channel & 0x03) * 2;
-
-	Adar_Write(p_adar, mem_addr_i, i_val, broadcast);
-	Adar_Write(p_adar, mem_addr_q, q_val, broadcast);
-	Adar_Write(p_adar, REG_LOAD_WORKING, 0x1, broadcast);
-
-	return(ADAR_ERROR_NOERROR);
-}
-
-
-/**
- * @brief 	Reset the whole ADAR device.
- *
- * @param	p_adar[in]	ADAR pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- */
-void Adar_SoftReset(const AdarDevice * p_adar)
-{
-	uint8_t instruction[3];
-
-	instruction[0] = ((p_adar->dev_addr & 0x03) << 5);
-	instruction[1] = 0x00;
-	instruction[2] = 0x81;
-
-	p_adar->Transfer(instruction, NULL, sizeof(instruction));
-}
-
-
-/**
- * @brief 	Reset ALL ADAR devices in the SPI chain.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- */
-void Adar_SoftResetAll(const AdarDevice * p_adar)
-{
-	uint8_t instruction[3];
-
-	instruction[0] = 0x08;
-	instruction[1] = 0x00;
-	instruction[2] = 0x81;
-
-	p_adar->Transfer(instruction, NULL, sizeof(instruction));
-}
-
-
-/**
- * @brief 	Write a byte of @param data to the register located at @param mem_addr.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param 	mem_addr  	Memory address of the register you wish to read from.
- * @param 	data      	Byte of data to be stored in the register.
- * @param 	broadcast	Send the message as a broadcast to all ADARs in the SPI chain
- 						if this set to BROADCAST_ON.
- *
- * @warning If writing the same data to multiple registers, use ADAR_WriteBlock.
- */
-void Adar_Write(const AdarDevice * p_adar, uint32_t mem_addr, uint8_t data, uint8_t broadcast)
-{
-	uint8_t instruction[3];
-	
-	if (broadcast)
-	{
-		instruction[0] = 0x08;
-	}
-	else
-	{
-		instruction[0] = ((p_adar->dev_addr & 0x03) << 5);
-	}
-
-	instruction[0] |= (0x1F00 & mem_addr) >> 8;
-	instruction[1] = (0xFF & mem_addr);
-	instruction[2] = data;
-
-	p_adar->Transfer(instruction, NULL, sizeof(instruction));
-}
-
-
-/**
- * @brief 	Block memory write to an ADAR device.
- *
- * @pre 	ADDR_ASCN BITS IN REGISTER ZERO MUST BE SET!
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param	mem_addr 	Memory address of the register you wish to read from.
- * @param	p_data[in]  Pointer to block of data to transfer (must have two unused bytes 
- 						preceding the data for instruction).
- * @param	size      	Size of data in bytes, including the two additional leading bytes.
- *
- * @warning First two bytes of data will be corrupted if you do not provide two unused leading bytes!
- */
-void Adar_WriteBlock(const AdarDevice * p_adar, uint16_t mem_addr, uint8_t * p_data, uint32_t size)
-{
-    // Prepare command
-	p_data[0] = ((p_adar->dev_addr & 0x03) << 5);
-	p_data[0] |= ((mem_addr) >> 8) & 0x1F;
-	p_data[1] = (0xFF & mem_addr);
-
-    // Start the transfer
-	p_adar->Transfer(p_data, NULL, size);
-
-    // Return nothing since we assume this is non-blocking and won't wait around
-}
-
-
-/**
- * @brief	Set contents of the INTERFACE_CONFIG_A register.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param 	flags     	#INTERFACE_CONFIG_A_SOFTRESET, #INTERFACE_CONFIG_A_LSB_FIRST,
- *                  	#INTERFACE_CONFIG_A_ADDR_ASCN, #INTERFACE_CONFIG_A_SDO_ACTIVE
- * @param 	broadcast	Send the message as a broadcast to all ADARs in the SPI chain
- *						if this set to BROADCAST_ON.
- */
-void Adar_WriteConfigA(const AdarDevice * p_adar, uint8_t flags, uint8_t broadcast)
-{
-	Adar_Write(p_adar, 0x00, flags, broadcast);
-}
-
-
-/**
- * @brief 	Write a byte of @param data to the register located at @param mem_addr and
- *			then read from the device and verify that the register was correctly set.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param 	mem_addr  	Memory address of the register you wish to read from.
- * @param 	data      	Byte of data to be stored in the register.
- *
- * @return	Returns the number of attempts that it took to successfully write to a register,
- *			starting from zero.
- * @warning This function currently only supports writes to a single regiter in a single ADAR.
- */
-uint8_t Adar_WriteVerify(const AdarDevice * p_adar, uint32_t mem_addr, uint8_t data)
-{
-	uint8_t rx_data;
-
-	for (uint8_t ii = 0; ii < 3; ii++)
-	{
-		Adar_Write(p_adar, mem_addr, data, 0);
-
-		// Can't read back from an ADAR with HW address 0
-		if (!((p_adar->dev_addr) % 4))
-		{
-			return(ADAR_ERROR_INVALIDADDR);
-		}
-		rx_data = Adar_Read(p_adar, mem_addr);
-		if (rx_data == data)
-		{
-			return(ii);
-		}
-	}
-
-	return(ADAR_ERROR_FAILED);
-}
-
-void Adar_SetBit(const AdarDevice * p_adar, uint32_t mem_addr, uint8_t bit, uint8_t broadcast)
-	{
-		uint8_t temp = Adar_Read(p_adar, mem_addr);
-		uint8_t data = temp|(1<<bit);
-		Adar_Write(p_adar,mem_addr, data,broadcast);
-	}
-
-void Adar_ResetBit(const AdarDevice * p_adar, uint32_t mem_addr, uint8_t bit, uint8_t broadcast)
-	{
-		uint8_t temp = Adar_Read(p_adar, mem_addr);
-		uint8_t data = temp&~(1<<bit);
-		Adar_Write(p_adar,mem_addr, data,broadcast);
-	}
-
@@ -1,294 +0,0 @@
-/**
- * MIT License
- * 
- * Copyright (c) 2020 Jimmy Pentz
- *
- * Reach me at: github.com/jgpentz, jpentz1( at )gmail.com
- * 
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sells
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- * 
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- * 
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-/* ADAR1000 4-Channel, X Band and Ku Band Beamformer */
-#ifndef LIB_ADAR1000_H_
-#define LIB_ADAR1000_H_
-
-#ifndef NULL
-#define NULL    (0)
-#endif
-
-// ----------------------------------------------------------------------------
-// Includes
-// ----------------------------------------------------------------------------
-#include "main.h"
-#include "stm32f7xx_hal.h"
-#include "stm32f7xx_hal_spi.h"
-#include "stm32f7xx_hal_gpio.h"
-#include <stdbool.h>
-#include <stdint.h>
-#include <string.h>
-
-#ifdef __cplusplus
-extern "C" {  // Prevent C++ name mangling
-#endif
-
-
-
-
-// ----------------------------------------------------------------------------
-// Datatypes
-// ----------------------------------------------------------------------------
-extern SPI_HandleTypeDef hspi1;
-extern const uint8_t VM_GAIN[128];
-extern const uint8_t VM_I[128];
-extern const uint8_t VM_Q[128];
-
-/// A function pointer prototype for a SPI transfer, the 3 parameters would be
-/// p_txData, p_rxData, and size (number of bytes to transfer), respectively.
-typedef uint32_t (*Adar_SpiTransfer)( uint8_t *, uint8_t *, uint32_t);
-
-typedef struct
- {
- 	uint8_t			 dev_addr; 		///< 2-bit device hardware address, 0x00, 0x01, 0x10, 0x11
- 	Adar_SpiTransfer Transfer;		///< Function pointer to the function used for SPI transfers
- 	uint8_t *		 p_rx_buffer;	///< Data buffer to store received bytes into
- }const AdarDevice;
-
-
-/// Use this to store bias current values into, as seen in the datasheet 
-/// Table 6. SPI Settings for Different Power Modules
-typedef struct
-{
-	uint8_t rx_lna;		///< nominal:  8, low power: 5
-	uint8_t rx_vm;		///< nominal:  5, low power: 2
-	uint8_t rx_vga;		///< nominal: 10, low power: 3
-	uint8_t tx_vm;		///< nominal:  5, low power: 2
-	uint8_t tx_vga;		///< nominal:  5, low power: 5
-	uint8_t tx_drv;		///< nominal:  6, low power: 3
-} AdarBiasCurrents;
-
-/// Useful for queries regarding the device info
-typedef struct
-{
-	uint8_t	 norm_operating_mode : 2;
-	uint8_t	 cust_operating_mode : 2;
-	uint8_t	 dev_status : 4;
-	uint8_t	 chip_type;
-	uint16_t product_id;
-	uint8_t	 scratchpad;
-	uint8_t	 spi_rev;
-	uint16_t vendor_id;
-	uint8_t	 rev_id;
-} AdarDeviceInfo;
-
-/// Return types for functions in this library
-typedef enum {
-	ADAR_ERROR_NOERROR		= 0,
-	ADAR_ERROR_FAILED		= 1,
-	ADAR_ERROR_INVALIDADDR	= 2,
-} AdarErrorCodes;
-
-
-// ----------------------------------------------------------------------------
-// Function Prototypes
-// ----------------------------------------------------------------------------
-void Adar_AdcInit(const AdarDevice * p_adar, uint8_t broadcast_bit);
-
-uint8_t Adar_AdcRead(const AdarDevice * p_adar, uint8_t broadcast_bit);
-
-uint8_t Adar_GetDeviceInfo(const AdarDevice * p_adar, AdarDeviceInfo * info);
-
-uint8_t Adar_Read(const AdarDevice * p_adar, uint32_t mem_addr);
-
-void Adar_ReadBlock(const AdarDevice * p_adar, uint16_t mem_addr, uint8_t * p_data, uint32_t size);
-
-uint8_t Adar_SetBiasCurrents(const AdarDevice * p_adar, AdarBiasCurrents * p_bias, uint8_t broadcast_bit);
-
-uint8_t Adar_SetBiasVoltages(const AdarDevice * p_adar, uint8_t bias_on_voltage[5], uint8_t bias_off_voltage[5]);
-
-uint8_t Adar_SetRamBypass(const AdarDevice * p_adar, uint8_t broadcast_bit);
-
-uint8_t Adar_SetRxVgaGain(const AdarDevice * p_adar, uint8_t channel, uint8_t vga_gain_db, uint8_t broadcast_bit);
-
-uint8_t Adar_SetRxPhase(const AdarDevice * p_adar, uint8_t channel, uint8_t phase, uint8_t broadcast_bit);
-
-uint8_t Adar_SetTxBias(const AdarDevice * p_adar, uint8_t broadcast_bit);
-
-uint8_t Adar_SetTxVgaGain(const AdarDevice * p_adar, uint8_t channel, uint8_t vga_gain_db, uint8_t broadcast_bit);
-
-uint8_t Adar_SetTxPhase(const AdarDevice * p_adar, uint8_t channel, uint8_t phase, uint8_t broadcast_bit);
-
-void Adar_SoftReset(const AdarDevice * p_adar);
-
-void Adar_SoftResetAll(const AdarDevice * p_adar);
-
-void Adar_Write(const AdarDevice * p_adar, uint32_t mem_addr, uint8_t data, uint8_t broadcast_bit);
-
-void Adar_WriteBlock(const AdarDevice * p_adar, uint16_t mem_addr, uint8_t * p_data, uint32_t size);
-
-void Adar_WriteConfigA(const AdarDevice * p_adar, uint8_t flags, uint8_t broadcast);
-
-uint8_t Adar_WriteVerify(const AdarDevice * p_adar, uint32_t mem_addr, uint8_t data);
-
-void Adar_SetBit(const AdarDevice * p_adar, uint32_t mem_addr, uint8_t bit, uint8_t broadcast);
-
-void Adar_ResetBit(const AdarDevice * p_adar, uint32_t mem_addr, uint8_t bit, uint8_t broadcast);
-
-
-// ----------------------------------------------------------------------------
-// Preprocessor Definitions and Constants
-// ----------------------------------------------------------------------------
-// Using BROADCAST_ON will send a command to all ADARs that share a bus
-#define BROADCAST_OFF					 0
-#define BROADCAST_ON					 1
-
-// The minimum size of a read from the ADARs consists of 3 bytes
-#define ADAR1000_RD_SIZE				 3
-
-// Address at which the TX RAM starts
-#define ADAR_TX_RAM_START_ADDR			 0x1800
-
-// ADC Defines
-#define ADAR1000_ADC_2MHZ_CLK			 0x00
-#define ADAR1000_ADC_EN					 0x60
-#define ADAR1000_ADC_ST_CONV			 0x70
-
-/* REGISTER DEFINITIONS */
-#define REG_INTERFACE_CONFIG_A			 0x000
-#define REG_INTERFACE_CONFIG_B			 0x001
-#define REG_DEV_CONFIG					 0x002
-#define REG_SCRATCHPAD					 0x00A
-#define REG_TRANSFER					 0x00F
-#define REG_CH1_RX_GAIN					 0x010
-#define REG_CH2_RX_GAIN					 0x011
-#define REG_CH3_RX_GAIN					 0x012
-#define REG_CH4_RX_GAIN					 0x013
-#define REG_CH1_RX_PHS_I				 0x014
-#define REG_CH1_RX_PHS_Q				 0x015
-#define REG_CH2_RX_PHS_I				 0x016
-#define REG_CH2_RX_PHS_Q				 0x017
-#define REG_CH3_RX_PHS_I				 0x018
-#define REG_CH3_RX_PHS_Q				 0x019
-#define REG_CH4_RX_PHS_I				 0x01A
-#define REG_CH4_RX_PHS_Q				 0x01B
-#define REG_CH1_TX_GAIN					 0x01C
-#define REG_CH2_TX_GAIN					 0x01D
-#define REG_CH3_TX_GAIN					 0x01E
-#define REG_CH4_TX_GAIN					 0x01F
-#define REG_CH1_TX_PHS_I				 0x020
-#define REG_CH1_TX_PHS_Q				 0x021
-#define REG_CH2_TX_PHS_I				 0x022
-#define REG_CH2_TX_PHS_Q				 0x023
-#define REG_CH3_TX_PHS_I				 0x024
-#define REG_CH3_TX_PHS_Q				 0x025
-#define REG_CH4_TX_PHS_I				 0x026
-#define REG_CH4_TX_PHS_Q				 0x027
-#define REG_LOAD_WORKING				 0x028
-#define REG_PA_CH1_BIAS_ON				 0x029
-#define REG_PA_CH2_BIAS_ON				 0x02A
-#define REG_PA_CH3_BIAS_ON				 0x02B
-#define REG_PA_CH4_BIAS_ON				 0x02C
-#define REG_LNA_BIAS_ON					 0x02D
-#define REG_RX_ENABLES					 0x02E
-#define REG_TX_ENABLES					 0x02F
-#define REG_MISC_ENABLES				 0x030
-#define REG_SW_CONTROL					 0x031
-#define REG_ADC_CONTROL					 0x032
-#define REG_ADC_CONTROL_TEMP_EN			 0xf0
-#define REG_ADC_OUT						 0x033
-#define REG_BIAS_CURRENT_RX_LNA			 0x034
-#define REG_BIAS_CURRENT_RX				 0x035
-#define REG_BIAS_CURRENT_TX				 0x036
-#define REG_BIAS_CURRENT_TX_DRV			 0x037
-#define REG_MEM_CTL						 0x038
-#define REG_RX_CHX_MEM					 0x039
-#define REG_TX_CHX_MEM					 0x03A
-#define REG_RX_CH1_MEM					 0x03D
-#define REG_RX_CH2_MEM					 0x03E
-#define REG_RX_CH3_MEM					 0x03F
-#define REG_RX_CH4_MEM					 0x040
-#define REG_TX_CH1_MEM					 0x041
-#define REG_TX_CH2_MEM					 0x042
-#define REG_TX_CH3_MEM					 0x043
-#define REG_TX_CH4_MEM					 0x044
-#define REG_PA_CH1_BIAS_OFF				 0x046
-#define REG_PA_CH2_BIAS_OFF				 0x047
-#define REG_PA_CH3_BIAS_OFF				 0x048
-#define REG_PA_CH4_BIAS_OFF				 0x049
-#define REG_LNA_BIAS_OFF				 0x04A
-#define REG_TX_BEAM_STEP_START			 0x04D
-#define REG_TX_BEAM_STEP_STOP			 0x04E
-#define REG_RX_BEAM_STEP_START			 0x04F
-#define REG_RX_BEAM_STEP_STOP			 0x050
-
-// REGISTER CONSTANTS
-#define INTERFACE_CONFIG_A_SOFTRESET	 	((1 << 7) | (1 << 0))
-#define INTERFACE_CONFIG_A_LSB_FIRST	 	((1 << 6) | (1 << 1))
-#define INTERFACE_CONFIG_A_ADDR_ASCN	 	((1 << 5) | (1 << 2))
-#define INTERFACE_CONFIG_A_SDO_ACTIVE		((1 << 4) | (1 << 3))
-
-#define LD_WRK_REGS_LDRX_OVERRIDE		   	(1 << 0)
-#define LD_WRK_REGS_LDTX_OVERRIDE		   	(1 << 1)
-
-#define RX_ENABLES_TX_VGA_EN			   	(1 << 0)
-#define RX_ENABLES_TX_VM_EN				   	(1 << 1)
-#define RX_ENABLES_TX_DRV_EN			   	(1 << 2)
-#define RX_ENABLES_CH3_TX_EN			   	(1 << 3)
-#define RX_ENABLES_CH2_TX_EN			   	(1 << 4)
-#define RX_ENABLES_CH1_TX_EN			   	(1 << 5)
-#define RX_ENABLES_CH0_TX_EN			   	(1 << 6)
-
-#define TX_ENABLES_TX_VGA_EN			   	(1 << 0)
-#define TX_ENABLES_TX_VM_EN				   	(1 << 1)
-#define TX_ENABLES_TX_DRV_EN			   	(1 << 2)
-#define TX_ENABLES_CH3_TX_EN			   	(1 << 3)
-#define TX_ENABLES_CH2_TX_EN			   	(1 << 4)
-#define TX_ENABLES_CH1_TX_EN			   	(1 << 5)
-#define TX_ENABLES_CH0_TX_EN			   	(1 << 6)
-
-#define MISC_ENABLES_CH4_DET_EN			   	(1 << 0)
-#define MISC_ENABLES_CH3_DET_EN			   	(1 << 1)
-#define MISC_ENABLES_CH2_DET_EN			   	(1 << 2)
-#define MISC_ENABLES_CH1_DET_EN			   	(1 << 3)
-#define MISC_ENABLES_LNA_BIAS_OUT_EN	   	(1 << 4)
-#define MISC_ENABLES_BIAS_EN			   	(1 << 5)
-#define MISC_ENABLES_BIAS_CTRL			   	(1 << 6)
-#define MISC_ENABLES_SW_DRV_TR_MODE_SEL	   	(1 << 7)
-
-#define SW_CTRL_POL						   	(1 << 0)
-#define SW_CTRL_TR_SPI					   	(1 << 1)
-#define SW_CTRL_TR_SOURCE				   	(1 << 2)
-#define SW_CTRL_SW_DRV_EN_POL			   	(1 << 3)
-#define SW_CTRL_SW_DRV_EN_TR			   	(1 << 4)
-#define SW_CTRL_RX_EN					   	(1 << 5)
-#define SW_CTRL_TX_EN					   	(1 << 6)
-#define SW_CTRL_SW_DRV_TR_STATE			   	(1 << 7)
-
-#define MEM_CTRL_RX_CHX_RAM_BYPASS		   	(1 << 0)
-#define MEM_CTRL_TX_CHX_RAM_BYPASS		   	(1 << 1)
-#define MEM_CTRL_RX_BEAM_STEP_EN		   	(1 << 2)
-#define MEM_CTRL_TX_BEAM_STEP_EN		   	(1 << 3)
-#define MEM_CTRL_BIAS_RAM_BYPASS		   	(1 << 5)
-#define MEM_CTRL_BEAM_RAM_BYPASS		   	(1 << 6)
-#define MEM_CTRL_SCAN_MODE_EN			   	(1 << 7)
-
-#ifdef __cplusplus
-}  // End extern "C"
-#endif
-
-#endif /* LIB_ADAR1000_H_ */
-
@@ -21,7 +21,6 @@
 #include "usb_device.h"
 #include "USBHandler.h"
 #include "usbd_cdc_if.h"
-#include "adar1000.h"
 #include "ADAR1000_Manager.h"
 #include "ADAR1000_AGC.h"
 extern "C" {
@@ -46,7 +45,9 @@ extern "C" {
 #include <vector>
 #include "stm32_spi.h"
 #include "stm32_delay.h"
-#include "TinyGPSPlus.h"
+extern "C" {
+#include "um982_gps.h"
+}
 extern "C" {
 #include "GY_85_HAL.h"
 }
@@ -121,8 +122,8 @@ UART_HandleTypeDef huart5;
 UART_HandleTypeDef huart3;

 /* USER CODE BEGIN PV */
-// The TinyGPSPlus object
-TinyGPSPlus gps;
+// UM982 dual-antenna GPS receiver
+UM982_GPS_t um982;

 // Global data structures
 GPS_Data_t current_gps_data = {0};
@@ -173,7 +174,7 @@ float RADAR_Altitude;
 double RADAR_Longitude = 0;
 double RADAR_Latitude = 0;

-extern uint8_t GUI_start_flag_received;
+extern uint8_t GUI_start_flag_received;  // [STM32-006] Legacy, unused -- kept for linker compat


 //RADAR
@@ -722,16 +723,13 @@ SystemError_t checkSystemHealth(void) {
        last_bmp_check = HAL_GetTick();
    }

-    // 6. Check GPS Communication
-    static uint32_t last_gps_fix = 0;
-    if (gps.location.isUpdated()) {
-        last_gps_fix = HAL_GetTick();
-    }
-    if (HAL_GetTick() - last_gps_fix > 30000) {
-        current_error = ERROR_GPS_COMM;
-        DIAG_WARN("SYS", "Health check: GPS no fix for >30s");
-        return current_error;
-    }
+    // 6. Check GPS Communication (30s grace period from boot / last valid fix)
+    uint32_t gps_fix_age = um982_position_age(&um982);
+    if (gps_fix_age > 30000) {
+        current_error = ERROR_GPS_COMM;
+        DIAG_WARN("SYS", "Health check: GPS no fix for >30s (age=%lu ms)", (unsigned long)gps_fix_age);
+        return current_error;
+    }

    // 7. Check RF Power Amplifier Current
    if (PowerAmplifier) {
@@ -1056,20 +1054,7 @@ static inline void delay_ms(uint32_t ms) { HAL_Delay(ms); }



-// This custom version of delay() ensures that the gps object
-// is being "fed".
-static void smartDelay(unsigned long ms)
-{
-    uint32_t start = HAL_GetTick();
-    uint8_t ch;
-
-    do {
-        // While there is new data available in UART (non-blocking)
-        if (HAL_UART_Receive(&huart5, &ch, 1, 0) == HAL_OK) {
-            gps.encode(ch);   // Pass received byte to TinyGPS++ equivalent parser
-        }
-    } while (HAL_GetTick() - start < ms);
-}
+// smartDelay removed -- replaced by non-blocking um982_process() in main loop

 // Small helper to enable DWT cycle counter for microdelay
 static void DWT_Init(void)
@@ -1213,7 +1198,14 @@ static int configure_ad9523(void)

    // init ad9523 defaults (fills any missing pdata defaults)
    DIAG("CLK", "Calling ad9523_init() -- fills pdata defaults");
-    ad9523_init(&init_param);
+    {
+        int32_t init_ret = ad9523_init(&init_param);
+        DIAG("CLK", "ad9523_init() returned %ld", (long)init_ret);
+        if (init_ret != 0) {
+            DIAG_ERR("CLK", "ad9523_init() FAILED (ret=%ld)", (long)init_ret);
+            return -1;
+        }
+    }

    /* [Bug #2 FIXED] Removed first ad9523_setup() call that was here.
     * It wrote to the chip while still in reset — writes were lost.
@@ -1602,6 +1594,12 @@ int main(void)
    Yaw_Sensor = (180*atan2(magRawY,magRawX)/PI) - Mag_Declination;

    if(Yaw_Sensor<0)Yaw_Sensor+=360;
+
+    // Override magnetometer heading with UM982 dual-antenna heading when available
+    if (um982_is_heading_valid(&um982)) {
+        Yaw_Sensor = um982_get_heading(&um982);
+    }
+
    RxEst_0 = RxEst_1;
    RyEst_0 = RyEst_1;
    RzEst_0 = RzEst_1;
@@ -1777,14 +1775,38 @@ int main(void)
  	//////////////////////////////////////////////////////////////////////////////////////
    //////////////////////////////////////////GPS/////////////////////////////////////////
    //////////////////////////////////////////////////////////////////////////////////////
-  for(int i=0; i<10;i++){
-  smartDelay(1000);
-  RADAR_Longitude = gps.location.lng();
-  RADAR_Latitude = gps.location.lat();
+  DIAG_SECTION("GPS INIT (UM982)");
+  DIAG("GPS", "Initializing UM982 on UART5 @ 115200 (baseline=50cm, tol=3cm)");
+  if (!um982_init(&um982, &huart5, 50.0f, 3.0f)) {
+      DIAG_WARN("GPS", "UM982 init: no VERSIONA response -- module may need more time");
+      // Not fatal: module may still start sending NMEA data after boot
+  } else {
+      DIAG("GPS", "UM982 init OK -- VERSIONA received");
  }

-  //move Stepper to position 1 = 0°
-  HAL_GPIO_WritePin(STEPPER_CW_P_GPIO_Port, STEPPER_CW_P_Pin, GPIO_PIN_RESET);//Set stepper motor spinning direction to CCW
+  // Collect GPS data for a few seconds (non-blocking pump)
+  DIAG("GPS", "Pumping GPS for 5 seconds to acquire initial fix...");
+  {
+      uint32_t gps_start = HAL_GetTick();
+      while (HAL_GetTick() - gps_start < 5000) {
+          um982_process(&um982);
+          HAL_Delay(10);
+      }
+  }
+  RADAR_Longitude = um982_get_longitude(&um982);
+  RADAR_Latitude = um982_get_latitude(&um982);
+  DIAG("GPS", "Initial position: lat=%.6f lon=%.6f fix=%d sats=%d",
+       RADAR_Latitude, RADAR_Longitude,
+       um982_get_fix_quality(&um982), um982_get_num_sats(&um982));
+
+  // Re-apply heading after GPS init so the north-alignment stepper move uses
+  // UM982 dual-antenna heading when available.
+  if (um982_is_heading_valid(&um982)) {
+      Yaw_Sensor = um982_get_heading(&um982);
+  }
+
+  //move Stepper to position 1 = 0°
+  HAL_GPIO_WritePin(STEPPER_CW_P_GPIO_Port, STEPPER_CW_P_Pin, GPIO_PIN_RESET);//Set stepper motor spinning direction to CCW
  //Point Stepper to North
  for(int i= 0;i<(int)(Yaw_Sensor*Stepper_steps/360);i++){
 	  HAL_GPIO_WritePin(STEPPER_CLK_P_GPIO_Port, STEPPER_CLK_P_Pin, GPIO_PIN_SET);
@@ -1806,29 +1828,11 @@ int main(void)
      HAL_UART_Transmit(&huart3, (uint8_t*)gps_send_error, sizeof(gps_send_error) - 1, 1000);
  }

-  // Check if start flag was received and settings are ready
-  do{
-	  if (usbHandler.isStartFlagReceived() &&
-		  usbHandler.getState() == USBHandler::USBState::READY_FOR_DATA) {
-
-		  const RadarSettings& settings = usbHandler.getSettings();
-
-		  // Use the settings to configure your radar system
-		  /*
-			  settings.getSystemFrequency();
-			  settings.getChirpDuration1();
-			  settings.getChirpDuration2();
-			  settings.getChirpsPerPosition();
-			  settings.getFreqMin();
-			  settings.getFreqMax();
-			  settings.getPRF1();
-			  settings.getPRF2();
-			  settings.getMaxDistance();
-			  */
-
-
-              }
-  }while(!usbHandler.isStartFlagReceived());
+  /* [STM32-006 FIXED] Removed blocking do-while loop that waited for
+   * usbHandler.isStartFlagReceived().  The production V7 PyQt GUI does not
+   * send the legacy 4-byte start flag [23,46,158,237], so this loop hung
+   * the MCU at boot indefinitely.  The USB settings handshake (if ever
+   * re-enabled) should be handled non-blocking in the main loop. */

  /***************************************************************/
  /************RF Power Amplifier Powering up sequence************/
@@ -2053,6 +2057,18 @@ int main(void)
 	        }
 	        DIAG("SYS", "Exited safe mode blink loop -- system_emergency_state cleared");
 	    }
+
+	  //////////////////////////////////////////////////////////////////////////////////////
+	  ////////////////////////// GPS: Non-blocking NMEA processing ////////////////////////
+	  //////////////////////////////////////////////////////////////////////////////////////
+	  um982_process(&um982);
+
+	  // Update position globals continuously
+	  if (um982_is_position_valid(&um982)) {
+	      RADAR_Latitude = um982_get_latitude(&um982);
+	      RADAR_Longitude = um982_get_longitude(&um982);
+	  }
+
 	  //////////////////////////////////////////////////////////////////////////////////////
 	  ////////////////////////// Monitor ADF4382A lock status periodically//////////////////
 	  //////////////////////////////////////////////////////////////////////////////////////
@@ -2163,9 +2179,24 @@ int main(void)

      runRadarPulseSequence();

-      /* [AGC] Outer-loop AGC: read FPGA saturation flag (DIG_5 / PD13),
-       * adjust ADAR1000 VGA common gain once per radar frame (~258 ms).
-       * Only run when AGC is enabled — otherwise leave VGA gains untouched. */
+      /* [AGC] Outer-loop AGC: sync enable from FPGA via DIG_6 (PD14),
+       * then read saturation flag (DIG_5 / PD13) and adjust ADAR1000 VGA
+       * common gain once per radar frame (~258 ms).
+       * FPGA register host_agc_enable is the single source of truth —
+       * DIG_6 propagates it to MCU every frame.
+       * 2-frame confirmation debounce: only change outerAgc.enabled when
+       * two consecutive frames read the same DIG_6 value. Prevents a
+       * single-sample glitch from causing a spurious AGC state transition.
+       * Added latency: 1 extra frame (~258 ms), acceptable for control plane. */
+      {
+          bool dig6_now = (HAL_GPIO_ReadPin(FPGA_DIG6_GPIO_Port,
+                                            FPGA_DIG6_Pin) == GPIO_PIN_SET);
+          static bool dig6_prev = false;  // matches boot default (AGC off)
+          if (dig6_now == dig6_prev) {
+              outerAgc.enabled = dig6_now;
+          }
+          dig6_prev = dig6_now;
+      }
      if (outerAgc.enabled) {
          bool sat = HAL_GPIO_ReadPin(FPGA_DIG5_SAT_GPIO_Port,
                                      FPGA_DIG5_SAT_Pin) == GPIO_PIN_SET;
@@ -2603,7 +2634,7 @@ static void MX_UART5_Init(void)

  /* USER CODE END UART5_Init 1 */
  huart5.Instance = UART5;
-  huart5.Init.BaudRate = 9600;
+  huart5.Init.BaudRate = 115200;
  huart5.Init.WordLength = UART_WORDLENGTH_8B;
  huart5.Init.StopBits = UART_STOPBITS_1;
  huart5.Init.Parity = UART_PARITY_NONE;
@@ -0,0 +1,586 @@
+/*******************************************************************************
+ * um982_gps.c -- UM982 dual-antenna GNSS receiver driver implementation
+ *
+ * See um982_gps.h for API documentation.
+ * Command syntax per Unicore N4 Command Reference EN R1.14.
+ ******************************************************************************/
+#include "um982_gps.h"
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+/* ========================= Internal helpers ========================== */
+
+/**
+ * Advance to the next comma-delimited field in an NMEA sentence.
+ * Returns pointer to the start of the next field (after the comma),
+ * or NULL if no more commas found before end-of-string or '*'.
+ *
+ * Handles empty fields (consecutive commas) correctly by returning
+ * a pointer to the character after the comma (which may be another comma).
+ */
+static const char *next_field(const char *p)
+{
+    if (p == NULL) return NULL;
+    while (*p != '\0' && *p != ',' && *p != '*') {
+        p++;
+    }
+    if (*p == ',') return p + 1;
+    return NULL;  /* End of sentence or checksum marker */
+}
+
+/**
+ * Get the length of the current field (up to next comma, '*', or '\0').
+ */
+static int field_len(const char *p)
+{
+    int len = 0;
+    if (p == NULL) return 0;
+    while (p[len] != '\0' && p[len] != ',' && p[len] != '*') {
+        len++;
+    }
+    return len;
+}
+
+/**
+ * Check if a field is non-empty (has at least one character before delimiter).
+ */
+static bool field_valid(const char *p)
+{
+    return p != NULL && field_len(p) > 0;
+}
+
+/**
+ * Parse a floating-point value from a field, returning 0.0 if empty.
+ */
+static double field_to_double(const char *p)
+{
+    if (!field_valid(p)) return 0.0;
+    return strtod(p, NULL);
+}
+
+static float field_to_float(const char *p)
+{
+    return (float)field_to_double(p);
+}
+
+static int field_to_int(const char *p)
+{
+    if (!field_valid(p)) return 0;
+    return (int)strtol(p, NULL, 10);
+}
+
+/* ========================= Checksum ================================== */
+
+bool um982_verify_checksum(const char *sentence)
+{
+    if (sentence == NULL || sentence[0] != '$') return false;
+
+    const char *p = sentence + 1;  /* Skip '$' */
+    uint8_t computed = 0;
+
+    while (*p != '\0' && *p != '*') {
+        computed ^= (uint8_t)*p;
+        p++;
+    }
+
+    if (*p != '*') return false;  /* No checksum marker found */
+    p++;  /* Skip '*' */
+
+    /* Parse 2-char hex checksum */
+    if (p[0] == '\0' || p[1] == '\0') return false;
+
+    char hex_str[3] = { p[0], p[1], '\0' };
+    unsigned long expected = strtoul(hex_str, NULL, 16);
+
+    return computed == (uint8_t)expected;
+}
+
+/* ========================= Coordinate parsing ======================== */
+
+double um982_parse_coord(const char *field, char hemisphere)
+{
+    if (field == NULL || field[0] == '\0') return NAN;
+
+    /* Find the decimal point to determine degree digit count.
+     * Latitude:  ddmm.mmmm  (dot at index 4, degrees = 2)
+     * Longitude: dddmm.mmmm (dot at index 5, degrees = 3)
+     * General:   degree_digits = dot_position - 2
+     */
+    const char *dot = strchr(field, '.');
+    if (dot == NULL) return NAN;
+
+    int dot_pos = (int)(dot - field);
+    int deg_digits = dot_pos - 2;
+
+    if (deg_digits < 1 || deg_digits > 3) return NAN;
+
+    /* Extract degree portion */
+    double degrees = 0.0;
+    for (int i = 0; i < deg_digits; i++) {
+        if (field[i] < '0' || field[i] > '9') return NAN;
+        degrees = degrees * 10.0 + (field[i] - '0');
+    }
+
+    /* Extract minutes portion (everything from deg_digits onward) */
+    double minutes = strtod(field + deg_digits, NULL);
+    if (minutes < 0.0 || minutes >= 60.0) return NAN;
+
+    double result = degrees + minutes / 60.0;
+
+    /* Apply hemisphere sign */
+    if (hemisphere == 'S' || hemisphere == 'W') {
+        result = -result;
+    }
+
+    return result;
+}
+
+/* ========================= Sentence parsers ========================== */
+
+/**
+ * Identify the NMEA sentence type by skipping the 2-char talker ID
+ * and comparing the 3-letter formatter.
+ *
+ * "$GNGGA,..." -> talker="GN", formatter="GGA"
+ * "$GPTHS,..." -> talker="GP", formatter="THS"
+ *
+ * Returns pointer to the formatter (3 chars at sentence+3), or NULL
+ * if sentence is too short.
+ */
+static const char *get_formatter(const char *sentence)
+{
+    /* sentence starts with '$', followed by 2-char talker + 3-char formatter */
+    if (sentence == NULL || strlen(sentence) < 6) return NULL;
+    return sentence + 3;  /* Skip "$XX" -> points to formatter */
+}
+
+/**
+ * Parse GGA sentence — position and fix quality.
+ *
+ * Format: $--GGA,time,lat,N/S,lon,E/W,quality,numSat,hdop,alt,M,geoidSep,M,dgpsAge,refID*XX
+ *         field:  1    2   3    4   5     6      7     8    9 10    11    12   13     14
+ */
+static void parse_gga(UM982_GPS_t *gps, const char *sentence)
+{
+    /* Skip to first field (after "$XXGGA,") */
+    const char *f = strchr(sentence, ',');
+    if (f == NULL) return;
+    f++;  /* f -> field 1 (time) */
+
+    /* Field 1: UTC time — skip for now */
+    const char *f2 = next_field(f);   /* lat */
+    const char *f3 = next_field(f2);  /* N/S */
+    const char *f4 = next_field(f3);  /* lon */
+    const char *f5 = next_field(f4);  /* E/W */
+    const char *f6 = next_field(f5);  /* quality */
+    const char *f7 = next_field(f6);  /* numSat */
+    const char *f8 = next_field(f7);  /* hdop */
+    const char *f9 = next_field(f8);  /* altitude */
+    const char *f10 = next_field(f9); /* M */
+    const char *f11 = next_field(f10); /* geoid sep */
+
+    uint32_t now = HAL_GetTick();
+
+    /* Parse fix quality first — if 0, position is meaningless */
+    gps->fix_quality = (uint8_t)field_to_int(f6);
+
+    /* Parse coordinates */
+    if (field_valid(f2) && field_valid(f3)) {
+        char hem = field_valid(f3) ? *f3 : 'N';
+        double lat = um982_parse_coord(f2, hem);
+        if (!isnan(lat)) gps->latitude = lat;
+    }
+
+    if (field_valid(f4) && field_valid(f5)) {
+        char hem = field_valid(f5) ? *f5 : 'E';
+        double lon = um982_parse_coord(f4, hem);
+        if (!isnan(lon)) gps->longitude = lon;
+    }
+
+    /* Number of satellites */
+    gps->num_satellites = (uint8_t)field_to_int(f7);
+
+    /* HDOP */
+    if (field_valid(f8)) {
+        gps->hdop = field_to_float(f8);
+    }
+
+    /* Altitude */
+    if (field_valid(f9)) {
+        gps->altitude = field_to_float(f9);
+    }
+
+    /* Geoid separation */
+    if (field_valid(f11)) {
+        gps->geoid_sep = field_to_float(f11);
+    }
+
+    gps->last_gga_tick = now;
+    if (gps->fix_quality != UM982_FIX_NONE) {
+        gps->last_fix_tick = now;
+    }
+}
+
+/**
+ * Parse RMC sentence — recommended minimum (position, speed, date).
+ *
+ * Format: $--RMC,time,status,lat,N/S,lon,E/W,speed,course,date,magVar,E/W,mode*XX
+ *         field:  1     2      3   4   5   6    7      8     9    10    11   12
+ */
+static void parse_rmc(UM982_GPS_t *gps, const char *sentence)
+{
+    const char *f = strchr(sentence, ',');
+    if (f == NULL) return;
+    f++;  /* f -> field 1 (time) */
+
+    const char *f2 = next_field(f);   /* status */
+    const char *f3 = next_field(f2);  /* lat */
+    const char *f4 = next_field(f3);  /* N/S */
+    const char *f5 = next_field(f4);  /* lon */
+    const char *f6 = next_field(f5);  /* E/W */
+    const char *f7 = next_field(f6);  /* speed knots */
+    const char *f8 = next_field(f7);  /* course true */
+
+    /* Status */
+    if (field_valid(f2)) {
+        gps->rmc_status = *f2;
+    }
+
+    /* Position (only if status = A for valid) */
+    if (field_valid(f2) && *f2 == 'A') {
+        if (field_valid(f3) && field_valid(f4)) {
+            double lat = um982_parse_coord(f3, *f4);
+            if (!isnan(lat)) gps->latitude = lat;
+        }
+        if (field_valid(f5) && field_valid(f6)) {
+            double lon = um982_parse_coord(f5, *f6);
+            if (!isnan(lon)) gps->longitude = lon;
+        }
+    }
+
+    /* Speed (knots) */
+    if (field_valid(f7)) {
+        gps->speed_knots = field_to_float(f7);
+    }
+
+    /* Course */
+    if (field_valid(f8)) {
+        gps->course_true = field_to_float(f8);
+    }
+
+    gps->last_rmc_tick = HAL_GetTick();
+}
+
+/**
+ * Parse THS sentence — true heading and status (UM982-specific).
+ *
+ * Format: $--THS,heading,mode*XX
+ *         field:    1      2
+ */
+static void parse_ths(UM982_GPS_t *gps, const char *sentence)
+{
+    const char *f = strchr(sentence, ',');
+    if (f == NULL) return;
+    f++;  /* f -> field 1 (heading) */
+
+    const char *f2 = next_field(f);  /* mode */
+
+    /* Heading */
+    if (field_valid(f)) {
+        gps->heading = field_to_float(f);
+    } else {
+        gps->heading = NAN;
+    }
+
+    /* Mode */
+    if (field_valid(f2)) {
+        gps->heading_mode = *f2;
+    } else {
+        gps->heading_mode = 'V';  /* Not valid if missing */
+    }
+
+    gps->last_ths_tick = HAL_GetTick();
+}
+
+/**
+ * Parse VTG sentence — course and speed over ground.
+ *
+ * Format: $--VTG,courseTrue,T,courseMag,M,speedKnots,N,speedKmh,K,mode*XX
+ *         field:     1      2     3      4     5      6    7     8   9
+ */
+static void parse_vtg(UM982_GPS_t *gps, const char *sentence)
+{
+    const char *f = strchr(sentence, ',');
+    if (f == NULL) return;
+    f++;  /* f -> field 1 (course true) */
+
+    const char *f2 = next_field(f);   /* T */
+    const char *f3 = next_field(f2);  /* course mag */
+    const char *f4 = next_field(f3);  /* M */
+    const char *f5 = next_field(f4);  /* speed knots */
+    const char *f6 = next_field(f5);  /* N */
+    const char *f7 = next_field(f6);  /* speed km/h */
+
+    /* Course true */
+    if (field_valid(f)) {
+        gps->course_true = field_to_float(f);
+    }
+
+    /* Speed knots */
+    if (field_valid(f5)) {
+        gps->speed_knots = field_to_float(f5);
+    }
+
+    /* Speed km/h */
+    if (field_valid(f7)) {
+        gps->speed_kmh = field_to_float(f7);
+    }
+
+    gps->last_vtg_tick = HAL_GetTick();
+}
+
+/* ========================= Sentence dispatch ========================= */
+
+void um982_parse_sentence(UM982_GPS_t *gps, const char *sentence)
+{
+    if (sentence == NULL || sentence[0] != '$') return;
+
+    /* Verify checksum before parsing */
+    if (!um982_verify_checksum(sentence)) return;
+
+    /* Check for VERSIONA response (starts with '#', not '$') -- handled separately */
+    /* Actually VERSIONA starts with '#', so it won't enter here. We check in feed(). */
+
+    /* Identify sentence type */
+    const char *fmt = get_formatter(sentence);
+    if (fmt == NULL) return;
+
+    if (strncmp(fmt, "GGA", 3) == 0) {
+        gps->initialized = true;
+        parse_gga(gps, sentence);
+    } else if (strncmp(fmt, "RMC", 3) == 0) {
+        gps->initialized = true;
+        parse_rmc(gps, sentence);
+    } else if (strncmp(fmt, "THS", 3) == 0) {
+        gps->initialized = true;
+        parse_ths(gps, sentence);
+    } else if (strncmp(fmt, "VTG", 3) == 0) {
+        gps->initialized = true;
+        parse_vtg(gps, sentence);
+    }
+    /* Other sentences silently ignored */
+}
+
+/* ========================= Command interface ========================= */
+
+bool um982_send_command(UM982_GPS_t *gps, const char *cmd)
+{
+    if (gps == NULL || gps->huart == NULL || cmd == NULL) return false;
+
+    /* Build command with \r\n termination */
+    char buf[UM982_CMD_BUF_SIZE];
+    int len = snprintf(buf, sizeof(buf), "%s\r\n", cmd);
+    if (len <= 0 || (size_t)len >= sizeof(buf)) return false;
+
+    HAL_StatusTypeDef status = HAL_UART_Transmit(
+        gps->huart, (const uint8_t *)buf, (uint16_t)len, 100);
+
+    return status == HAL_OK;
+}
+
+/* ========================= Line assembly + feed ====================== */
+
+/**
+ * Process a completed line from the line buffer.
+ */
+static void process_line(UM982_GPS_t *gps, const char *line)
+{
+    if (line == NULL || line[0] == '\0') return;
+
+    /* NMEA sentence starts with '$' */
+    if (line[0] == '$') {
+        um982_parse_sentence(gps, line);
+        return;
+    }
+
+    /* Unicore proprietary response starts with '#' (e.g. #VERSIONA) */
+    if (line[0] == '#') {
+        if (strncmp(line + 1, "VERSIONA", 8) == 0) {
+            gps->version_received = true;
+            gps->initialized = true;
+        }
+        return;
+    }
+}
+
+void um982_feed(UM982_GPS_t *gps, const uint8_t *data, uint16_t len)
+{
+    if (gps == NULL || data == NULL || len == 0) return;
+
+    for (uint16_t i = 0; i < len; i++) {
+        uint8_t ch = data[i];
+
+        /* End of line: process if we have content */
+        if (ch == '\n' || ch == '\r') {
+            if (gps->line_len > 0 && !gps->line_overflow) {
+                gps->line_buf[gps->line_len] = '\0';
+                process_line(gps, gps->line_buf);
+            }
+            gps->line_len = 0;
+            gps->line_overflow = false;
+            continue;
+        }
+
+        /* Accumulate into line buffer */
+        if (gps->line_len < UM982_LINE_BUF_SIZE - 1) {
+            gps->line_buf[gps->line_len++] = (char)ch;
+        } else {
+            gps->line_overflow = true;
+        }
+    }
+}
+
+/* ========================= UART process (production) ================= */
+
+void um982_process(UM982_GPS_t *gps)
+{
+    if (gps == NULL || gps->huart == NULL) return;
+
+    /* Read all available bytes from the UART one at a time.
+     * At 115200 baud (~11.5 KB/s) and a typical main-loop period of ~10 ms,
+     * we expect ~115 bytes per call — negligible overhead on a 168 MHz STM32.
+     *
+     * Note: batch reads (HAL_UART_Receive with Size > 1 and Timeout = 0) are
+     * NOT safe here because the HAL consumes bytes from the data register as
+     * it reads them.  If fewer than Size bytes are available, the consumed
+     * bytes are lost (HAL_TIMEOUT is returned and the caller has no way to
+     * know how many bytes were actually placed into the buffer). */
+    uint8_t ch;
+    while (HAL_UART_Receive(gps->huart, &ch, 1, 0) == HAL_OK) {
+        um982_feed(gps, &ch, 1);
+    }
+}
+
+/* ========================= Validity checks =========================== */
+
+bool um982_is_heading_valid(const UM982_GPS_t *gps)
+{
+    if (gps == NULL) return false;
+    if (isnan(gps->heading)) return false;
+
+    /* Mode must be Autonomous or Differential */
+    if (gps->heading_mode != 'A' && gps->heading_mode != 'D') return false;
+
+    /* Check age */
+    uint32_t age = HAL_GetTick() - gps->last_ths_tick;
+    return age < UM982_HEADING_TIMEOUT_MS;
+}
+
+bool um982_is_position_valid(const UM982_GPS_t *gps)
+{
+    if (gps == NULL) return false;
+    if (gps->fix_quality == UM982_FIX_NONE) return false;
+
+    /* Check age of the last valid fix */
+    uint32_t age = HAL_GetTick() - gps->last_fix_tick;
+    return age < UM982_POSITION_TIMEOUT_MS;
+}
+
+uint32_t um982_heading_age(const UM982_GPS_t *gps)
+{
+    if (gps == NULL) return UINT32_MAX;
+    return HAL_GetTick() - gps->last_ths_tick;
+}
+
+uint32_t um982_position_age(const UM982_GPS_t *gps)
+{
+    if (gps == NULL) return UINT32_MAX;
+    return HAL_GetTick() - gps->last_fix_tick;
+}
+
+/* ========================= Initialization ============================ */
+
+bool um982_init(UM982_GPS_t *gps, UART_HandleTypeDef *huart,
+                float baseline_cm, float tolerance_cm)
+{
+    if (gps == NULL || huart == NULL) return false;
+
+    /* Zero-init entire structure */
+    memset(gps, 0, sizeof(UM982_GPS_t));
+
+    gps->huart = huart;
+    gps->heading = NAN;
+    gps->heading_mode = 'V';
+    gps->rmc_status = 'V';
+    gps->speed_knots = 0.0f;
+
+    /* Seed fix timestamp so position_age() returns ~0 instead of uptime.
+     * Gives the module a full 30s grace window from init to acquire a fix
+     * before the health check fires ERROR_GPS_COMM. */
+    gps->last_fix_tick = HAL_GetTick();
+    gps->speed_kmh = 0.0f;
+    gps->course_true = 0.0f;
+
+    /* Step 1: Stop all current output to get a clean slate */
+    um982_send_command(gps, "UNLOG");
+    HAL_Delay(100);
+
+    /* Step 2: Configure heading mode
+     * Per N4 Reference 4.18: CONFIG HEADING FIXLENGTH (default mode)
+     * "The distance between ANT1 and ANT2 is fixed. They move synchronously." */
+    um982_send_command(gps, "CONFIG HEADING FIXLENGTH");
+    HAL_Delay(50);
+
+    /* Step 3: Set baseline length if specified
+     * Per N4 Reference: CONFIG HEADING LENGTH <cm> <tolerance_cm>
+     * "parameter1: Fixed baseline length (cm), valid range >= 0"
+     * "parameter2: Tolerable error margin (cm), valid range > 0" */
+    if (baseline_cm > 0.0f) {
+        char cmd[64];
+        if (tolerance_cm > 0.0f) {
+            snprintf(cmd, sizeof(cmd), "CONFIG HEADING LENGTH %.0f %.0f",
+                     baseline_cm, tolerance_cm);
+        } else {
+            snprintf(cmd, sizeof(cmd), "CONFIG HEADING LENGTH %.0f",
+                     baseline_cm);
+        }
+        um982_send_command(gps, cmd);
+        HAL_Delay(50);
+    }
+
+    /* Step 4: Enable NMEA output sentences on COM2.
+     * Per N4 Reference: "When requesting NMEA messages, users should add GP
+     * before each command name"
+     *
+     * We target COM2 because the ELT0213 board (GNSS.STORE) exposes COM2
+     * (RXD2/TXD2) on its 12-pin JST connector (pins 5 & 6).  The STM32
+     * UART5 (PC12-TX, PD2-RX) connects to these pins via JP8.
+     * COM2 defaults to 115200 baud — matching our UART5 config. */
+    um982_send_command(gps, "GPGGA COM2 1");     /* GGA at 1 Hz */
+    HAL_Delay(50);
+    um982_send_command(gps, "GPRMC COM2 1");     /* RMC at 1 Hz */
+    HAL_Delay(50);
+    um982_send_command(gps, "GPTHS COM2 0.2");   /* THS at 5 Hz (heading primary) */
+    HAL_Delay(50);
+
+    /* Step 5: Skip SAVECONFIG -- NMEA config is re-sent every boot anyway.
+     * Saving to NVM on every power cycle would wear flash.  If persistent
+     * config is needed, call um982_send_command(gps, "SAVECONFIG") once
+     * during commissioning. */
+
+    /* Step 6: Query version to verify communication */
+    gps->version_received = false;
+    um982_send_command(gps, "VERSIONA");
+
+    /* Wait for VERSIONA response (non-blocking poll) */
+    uint32_t start = HAL_GetTick();
+    while (!gps->version_received &&
+           (HAL_GetTick() - start) < UM982_INIT_TIMEOUT_MS) {
+        um982_process(gps);
+        HAL_Delay(10);
+    }
+
+    gps->initialized = gps->version_received;
+    return gps->initialized;
+}
@@ -0,0 +1,213 @@
+/*******************************************************************************
+ * um982_gps.h -- UM982 dual-antenna GNSS receiver driver
+ *
+ * Parses NMEA sentences (GGA, RMC, THS, VTG) from the Unicore UM982 module
+ * and provides position, heading, and velocity data.
+ *
+ * Design principles:
+ *   - Non-blocking: process() reads available UART bytes without waiting
+ *   - Correct NMEA parsing: proper tokenizer handles empty fields
+ *   - Longitude handles 3-digit degrees (dddmm.mmmm) via decimal-point detection
+ *   - Checksum verified on every sentence
+ *   - Command syntax verified against Unicore N4 Command Reference EN R1.14
+ *
+ * Hardware: UM982 on UART5 @ 115200 baud, dual-antenna heading mode
+ ******************************************************************************/
+#ifndef UM982_GPS_H
+#define UM982_GPS_H
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <math.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Forward-declare the HAL UART handle type.  The real definition comes from
+ * stm32f7xx_hal.h (production) or stm32_hal_mock.h (tests). */
+#ifndef STM32_HAL_MOCK_H
+#include "stm32f7xx_hal.h"
+#else
+/* Already included via mock -- nothing to do */
+#endif
+
+/* ========================= Constants ================================= */
+
+#define UM982_RX_BUF_SIZE    512   /* Ring buffer for incoming UART bytes */
+#define UM982_LINE_BUF_SIZE   96   /* Max NMEA sentence (82 chars + margin) */
+#define UM982_CMD_BUF_SIZE   128   /* Outgoing command buffer */
+#define UM982_INIT_TIMEOUT_MS 3000 /* Timeout waiting for VERSIONA response */
+
+/* Fix quality values (from GGA field 6) */
+#define UM982_FIX_NONE       0
+#define UM982_FIX_GPS        1
+#define UM982_FIX_DGPS       2
+#define UM982_FIX_RTK_FIXED  4
+#define UM982_FIX_RTK_FLOAT  5
+
+/* Validity timeout defaults (ms) */
+#define UM982_HEADING_TIMEOUT_MS 2000
+#define UM982_POSITION_TIMEOUT_MS 5000
+
+/* ========================= Data Types ================================ */
+
+typedef struct {
+    /* Position */
+    double   latitude;       /* Decimal degrees, positive = North */
+    double   longitude;      /* Decimal degrees, positive = East */
+    float    altitude;       /* Meters above MSL */
+    float    geoid_sep;      /* Geoid separation (meters) */
+
+    /* Heading (from dual-antenna THS) */
+    float    heading;        /* True heading 0-360 degrees, NAN if invalid */
+    char     heading_mode;   /* A=autonomous, D=diff, E=est, M=manual, S=sim, V=invalid */
+
+    /* Velocity */
+    float    speed_knots;    /* Speed over ground (knots) */
+    float    speed_kmh;      /* Speed over ground (km/h) */
+    float    course_true;    /* Course over ground (degrees true) */
+
+    /* Quality */
+    uint8_t  fix_quality;    /* 0=none, 1=GPS, 2=DGPS, 4=RTK fixed, 5=RTK float */
+    uint8_t  num_satellites; /* Satellites used in fix */
+    float    hdop;           /* Horizontal dilution of precision */
+
+    /* RMC status */
+    char     rmc_status;     /* A=valid, V=warning */
+
+    /* Timestamps (HAL_GetTick() at last update) */
+    uint32_t last_fix_tick;   /* Last valid GGA fix (fix_quality > 0) */
+    uint32_t last_gga_tick;
+    uint32_t last_rmc_tick;
+    uint32_t last_ths_tick;
+    uint32_t last_vtg_tick;
+
+    /* Communication state */
+    bool     initialized;      /* VERSIONA or supported NMEA traffic seen */
+    bool     version_received; /* VERSIONA response seen */
+
+    /* ---- Internal parser state (not for external use) ---- */
+
+    /* Ring buffer */
+    uint8_t  rx_buf[UM982_RX_BUF_SIZE];
+    uint16_t rx_head;        /* Write index */
+    uint16_t rx_tail;        /* Read index */
+
+    /* Line assembler */
+    char     line_buf[UM982_LINE_BUF_SIZE];
+    uint8_t  line_len;
+    bool     line_overflow;  /* Current line exceeded buffer */
+
+    /* UART handle */
+    UART_HandleTypeDef *huart;
+
+} UM982_GPS_t;
+
+/* ========================= Public API ================================ */
+
+/**
+ * Initialize the UM982_GPS_t structure and configure the module.
+ *
+ * Sends: UNLOG, CONFIG HEADING, optional CONFIG HEADING LENGTH,
+ *        GPGGA, GPRMC, GPTHS
+ * Queries VERSIONA to verify communication.
+ *
+ * @param gps          Pointer to UM982_GPS_t instance
+ * @param huart        UART handle (e.g. &huart5)
+ * @param baseline_cm  Distance between antennas in cm (0 = use module default)
+ * @param tolerance_cm Baseline tolerance in cm (0 = use module default)
+ * @return true if VERSIONA response received within timeout
+ */
+bool um982_init(UM982_GPS_t *gps, UART_HandleTypeDef *huart,
+                float baseline_cm, float tolerance_cm);
+
+/**
+ * Process available UART data. Call from main loop — non-blocking.
+ *
+ * Reads all available bytes from UART, assembles lines, and dispatches
+ * complete NMEA sentences to the appropriate parser.
+ *
+ * @param gps  Pointer to UM982_GPS_t instance
+ */
+void um982_process(UM982_GPS_t *gps);
+
+/**
+ * Feed raw bytes directly into the parser (useful for testing).
+ * In production, um982_process() calls this internally after UART read.
+ *
+ * @param gps   Pointer to UM982_GPS_t instance
+ * @param data  Pointer to byte array
+ * @param len   Number of bytes
+ */
+void um982_feed(UM982_GPS_t *gps, const uint8_t *data, uint16_t len);
+
+/* ---- Getters ---- */
+
+static inline float    um982_get_heading(const UM982_GPS_t *gps)     { return gps->heading; }
+static inline double   um982_get_latitude(const UM982_GPS_t *gps)    { return gps->latitude; }
+static inline double   um982_get_longitude(const UM982_GPS_t *gps)   { return gps->longitude; }
+static inline float    um982_get_altitude(const UM982_GPS_t *gps)    { return gps->altitude; }
+static inline uint8_t  um982_get_fix_quality(const UM982_GPS_t *gps) { return gps->fix_quality; }
+static inline uint8_t  um982_get_num_sats(const UM982_GPS_t *gps)    { return gps->num_satellites; }
+static inline float    um982_get_hdop(const UM982_GPS_t *gps)        { return gps->hdop; }
+static inline float    um982_get_speed_knots(const UM982_GPS_t *gps) { return gps->speed_knots; }
+static inline float    um982_get_speed_kmh(const UM982_GPS_t *gps)   { return gps->speed_kmh; }
+static inline float    um982_get_course(const UM982_GPS_t *gps)      { return gps->course_true; }
+
+/**
+ * Check if heading is valid (mode A or D, and within timeout).
+ */
+bool um982_is_heading_valid(const UM982_GPS_t *gps);
+
+/**
+ * Check if position is valid (fix_quality > 0, and within timeout).
+ */
+bool um982_is_position_valid(const UM982_GPS_t *gps);
+
+/**
+ * Get age of last heading update in milliseconds.
+ */
+uint32_t um982_heading_age(const UM982_GPS_t *gps);
+
+/**
+ * Get age of the last valid position fix in milliseconds.
+ */
+uint32_t um982_position_age(const UM982_GPS_t *gps);
+
+/* ========================= Internal (exposed for testing) ============ */
+
+/**
+ * Verify NMEA checksum. Returns true if valid.
+ * Sentence must start with '$' and contain '*XX' before termination.
+ */
+bool um982_verify_checksum(const char *sentence);
+
+/**
+ * Parse a complete NMEA line (with $ prefix and *XX checksum).
+ * Dispatches to GGA/RMC/THS/VTG parsers as appropriate.
+ */
+void um982_parse_sentence(UM982_GPS_t *gps, const char *sentence);
+
+/**
+ * Parse NMEA coordinate string to decimal degrees.
+ * Works for both latitude (ddmm.mmmm) and longitude (dddmm.mmmm)
+ * by detecting the decimal point position.
+ *
+ * @param field     NMEA coordinate field (e.g. "4404.14036" or "12118.85961")
+ * @param hemisphere 'N', 'S', 'E', or 'W'
+ * @return Decimal degrees (negative for S/W), or NAN on parse error
+ */
+double um982_parse_coord(const char *field, char hemisphere);
+
+/**
+ * Send a command to the UM982. Appends \r\n automatically.
+ * @return true if UART transmit succeeded
+ */
+bool um982_send_command(UM982_GPS_t *gps, const char *cmd);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* UM982_GPS_H */
@@ -27,6 +27,10 @@ CXX_LIB_DIR := ../9_1_1_C_Cpp_Libraries
 CXX_SRCS    := $(CXX_LIB_DIR)/ADAR1000_AGC.cpp $(CXX_LIB_DIR)/ADAR1000_Manager.cpp
 CXX_OBJS    := ADAR1000_AGC.o ADAR1000_Manager.o

+# GPS driver source
+GPS_SRC := ../9_1_3_C_Cpp_Code/um982_gps.c
+GPS_OBJ := um982_gps.o
+
 # Real source files compiled against mock headers
 REAL_SRC := ../9_1_1_C_Cpp_Libraries/adf4382a_manager.c

@@ -74,7 +78,10 @@ TESTS_WITH_PLATFORM := test_bug11_platform_spi_transmit_only
 # C++ tests (AGC outer loop)
 TESTS_WITH_CXX := test_agc_outer_loop

-ALL_TESTS := $(TESTS_WITH_REAL) $(TESTS_MOCK_ONLY) $(TESTS_STANDALONE) $(TESTS_WITH_PLATFORM) $(TESTS_WITH_CXX)
+# GPS driver tests (need mocks + GPS source + -lm)
+TESTS_GPS := test_um982_gps
+
+ALL_TESTS := $(TESTS_WITH_REAL) $(TESTS_MOCK_ONLY) $(TESTS_STANDALONE) $(TESTS_WITH_PLATFORM) $(TESTS_WITH_CXX) $(TESTS_GPS)

 .PHONY: all build test clean \
        $(addprefix test_,bug1 bug2 bug3 bug4 bug5 bug6 bug7 bug8 bug9 bug10 bug11 bug12 bug13 bug14 bug15) \
@@ -193,6 +200,20 @@ test_agc_outer_loop: test_agc_outer_loop.cpp $(CXX_OBJS) $(MOCK_OBJS)
 test_agc: test_agc_outer_loop
 	./test_agc_outer_loop

+# --- GPS driver rules ---
+
+$(GPS_OBJ): $(GPS_SRC)
+	$(CC) $(CFLAGS) $(INCLUDES) -I../9_1_3_C_Cpp_Code -c $< -o $@
+
+# Note: test includes um982_gps.c directly for white-box testing (static fn access)
+test_um982_gps: test_um982_gps.c $(MOCK_OBJS)
+	$(CC) $(CFLAGS) $(INCLUDES) -I../9_1_3_C_Cpp_Code $< $(MOCK_OBJS) -lm -o $@
+
+# Convenience target
+.PHONY: test_gps
+test_gps: test_um982_gps
+	./test_um982_gps
+
 # --- Individual test targets ---

 test_bug1: test_bug1_timed_sync_init_ordering
@@ -21,6 +21,7 @@ SPI_HandleTypeDef  hspi4 = { .id = 4 };
 I2C_HandleTypeDef  hi2c1 = { .id = 1 };
 I2C_HandleTypeDef  hi2c2 = { .id = 2 };
 UART_HandleTypeDef huart3 = { .id = 3 };
+UART_HandleTypeDef huart5 = { .id = 5 };  /* GPS UART */
 ADC_HandleTypeDef  hadc3 = { .id = 3 };
 TIM_HandleTypeDef  htim3 = { .id = 3 };

@@ -34,6 +35,26 @@ uint32_t mock_tick = 0;
 /* ========================= Printf control ========================= */
 int mock_printf_enabled = 0;

+/* ========================= Mock UART TX capture =================== */
+uint8_t  mock_uart_tx_buf[MOCK_UART_TX_BUF_SIZE];
+uint16_t mock_uart_tx_len = 0;
+
+/* ========================= Mock UART RX buffer ==================== */
+#define MOCK_UART_RX_SLOTS 8
+
+static struct {
+    uint32_t uart_id;
+    uint8_t  buf[MOCK_UART_RX_BUF_SIZE];
+    uint16_t head;
+    uint16_t tail;
+} mock_uart_rx[MOCK_UART_RX_SLOTS];
+
+void mock_uart_tx_clear(void)
+{
+    mock_uart_tx_len = 0;
+    memset(mock_uart_tx_buf, 0, sizeof(mock_uart_tx_buf));
+}
+
 /* ========================= Mock GPIO read ========================= */
 #define GPIO_READ_TABLE_SIZE 32
 static struct {
@@ -49,6 +70,9 @@ void spy_reset(void)
    mock_tick = 0;
    mock_printf_enabled = 0;
    memset(gpio_read_table, 0, sizeof(gpio_read_table));
+    memset(mock_uart_rx, 0, sizeof(mock_uart_rx));
+    mock_uart_tx_len = 0;
+    memset(mock_uart_tx_buf, 0, sizeof(mock_uart_tx_buf));
 }

 const SpyRecord *spy_get(int index)
@@ -185,6 +209,83 @@ HAL_StatusTypeDef HAL_UART_Transmit(UART_HandleTypeDef *huart, const uint8_t *pD
        .value = Timeout,
        .extra = huart
    });
+    /* Capture TX data for test inspection */
+    for (uint16_t i = 0; i < Size && mock_uart_tx_len < MOCK_UART_TX_BUF_SIZE; i++) {
+        mock_uart_tx_buf[mock_uart_tx_len++] = pData[i];
+    }
+    return HAL_OK;
+}
+
+/* ========================= Mock UART RX helpers ====================== */
+
+/* find_rx_slot, mock_uart_rx_load, etc. use the mock_uart_rx declared above */
+
+static int find_rx_slot(UART_HandleTypeDef *huart)
+{
+    if (huart == NULL) return -1;
+    /* Find existing slot */
+    for (int i = 0; i < MOCK_UART_RX_SLOTS; i++) {
+        if (mock_uart_rx[i].uart_id == huart->id && mock_uart_rx[i].head != mock_uart_rx[i].tail) {
+            return i;
+        }
+        if (mock_uart_rx[i].uart_id == huart->id) {
+            return i;
+        }
+    }
+    /* Find empty slot */
+    for (int i = 0; i < MOCK_UART_RX_SLOTS; i++) {
+        if (mock_uart_rx[i].uart_id == 0) {
+            mock_uart_rx[i].uart_id = huart->id;
+            return i;
+        }
+    }
+    return -1;
+}
+
+void mock_uart_rx_load(UART_HandleTypeDef *huart, const uint8_t *data, uint16_t len)
+{
+    int slot = find_rx_slot(huart);
+    if (slot < 0) return;
+    mock_uart_rx[slot].uart_id = huart->id;
+    for (uint16_t i = 0; i < len; i++) {
+        uint16_t next = (mock_uart_rx[slot].head + 1) % MOCK_UART_RX_BUF_SIZE;
+        if (next == mock_uart_rx[slot].tail) break;  /* Buffer full */
+        mock_uart_rx[slot].buf[mock_uart_rx[slot].head] = data[i];
+        mock_uart_rx[slot].head = next;
+    }
+}
+
+void mock_uart_rx_clear(UART_HandleTypeDef *huart)
+{
+    int slot = find_rx_slot(huart);
+    if (slot < 0) return;
+    mock_uart_rx[slot].head = 0;
+    mock_uart_rx[slot].tail = 0;
+}
+
+HAL_StatusTypeDef HAL_UART_Receive(UART_HandleTypeDef *huart, uint8_t *pData,
+                                    uint16_t Size, uint32_t Timeout)
+{
+    (void)Timeout;
+    int slot = find_rx_slot(huart);
+    if (slot < 0) return HAL_TIMEOUT;
+
+    for (uint16_t i = 0; i < Size; i++) {
+        if (mock_uart_rx[slot].head == mock_uart_rx[slot].tail) {
+            return HAL_TIMEOUT;  /* No more data */
+        }
+        pData[i] = mock_uart_rx[slot].buf[mock_uart_rx[slot].tail];
+        mock_uart_rx[slot].tail = (mock_uart_rx[slot].tail + 1) % MOCK_UART_RX_BUF_SIZE;
+    }
+
+    spy_push((SpyRecord){
+        .type  = SPY_UART_RX,
+        .port  = NULL,
+        .pin   = Size,
+        .value = Timeout,
+        .extra = huart
+    });
+
    return HAL_OK;
 }

@@ -105,6 +105,7 @@ typedef struct {
 extern SPI_HandleTypeDef  hspi1, hspi4;
 extern I2C_HandleTypeDef  hi2c1, hi2c2;
 extern UART_HandleTypeDef huart3;
+extern UART_HandleTypeDef huart5;  /* GPS UART */
 extern ADC_HandleTypeDef  hadc3;
 extern TIM_HandleTypeDef  htim3;  /* Timer for DELADJ PWM */

@@ -139,6 +140,7 @@ typedef enum {
    SPY_TIM_SET_COMPARE,
    SPY_SPI_TRANSMIT_RECEIVE,
    SPY_SPI_TRANSMIT,
+    SPY_UART_RX,
 } SpyCallType;

 typedef struct {
@@ -187,6 +189,23 @@ void          HAL_GPIO_TogglePin(GPIO_TypeDef *GPIOx, uint16_t GPIO_Pin);
 uint32_t      HAL_GetTick(void);
 void          HAL_Delay(uint32_t Delay);
 HAL_StatusTypeDef HAL_UART_Transmit(UART_HandleTypeDef *huart, const uint8_t *pData, uint16_t Size, uint32_t Timeout);
+HAL_StatusTypeDef HAL_UART_Receive(UART_HandleTypeDef *huart, uint8_t *pData, uint16_t Size, uint32_t Timeout);
+
+/* ========================= Mock UART RX buffer ======================= */
+
+/* Inject bytes into the mock UART RX buffer for a specific UART handle.
+ * HAL_UART_Receive will return these bytes one at a time. */
+#define MOCK_UART_RX_BUF_SIZE 2048
+
+void mock_uart_rx_load(UART_HandleTypeDef *huart, const uint8_t *data, uint16_t len);
+void mock_uart_rx_clear(UART_HandleTypeDef *huart);
+
+/* Capture buffer for UART TX data (to verify commands sent to GPS module) */
+#define MOCK_UART_TX_BUF_SIZE 2048
+
+extern uint8_t  mock_uart_tx_buf[MOCK_UART_TX_BUF_SIZE];
+extern uint16_t mock_uart_tx_len;
+void mock_uart_tx_clear(void);

 /* ========================= SPI stubs ============================== */

@@ -50,7 +50,7 @@ static void test_defaults()
    assert(agc.min_gain == 0);
    assert(agc.max_gain == 127);
    assert(agc.holdoff_frames == 4);
-    assert(agc.enabled == true);
+    assert(agc.enabled == false);  // disabled by default — FPGA DIG_6 is source of truth
    assert(agc.holdoff_counter == 0);
    assert(agc.last_saturated == false);
    assert(agc.saturation_event_count == 0);
@@ -67,6 +67,7 @@ static void test_defaults()
 static void test_saturation_reduces_gain()
 {
    ADAR1000_AGC agc;
+    agc.enabled = true;  // default is OFF; enable for this test
    uint8_t initial = agc.agc_base_gain;  // 30

    agc.update(true);  // saturation
@@ -82,6 +83,7 @@ static void test_saturation_reduces_gain()
 static void test_holdoff_prevents_early_gain_up()
 {
    ADAR1000_AGC agc;
+    agc.enabled = true;  // default is OFF; enable for this test
    agc.update(true);  // saturate once -> gain = 26
    uint8_t after_sat = agc.agc_base_gain;

@@ -101,6 +103,7 @@ static void test_holdoff_prevents_early_gain_up()
 static void test_recovery_after_holdoff()
 {
    ADAR1000_AGC agc;
+    agc.enabled = true;  // default is OFF; enable for this test
    agc.update(true);  // saturate -> gain = 26
    uint8_t after_sat = agc.agc_base_gain;

@@ -119,6 +122,7 @@ static void test_recovery_after_holdoff()
 static void test_min_gain_clamp()
 {
    ADAR1000_AGC agc;
+    agc.enabled = true;  // default is OFF; enable for this test
    agc.min_gain = 10;
    agc.agc_base_gain = 12;
    agc.gain_step_down = 4;
@@ -136,6 +140,7 @@ static void test_min_gain_clamp()
 static void test_max_gain_clamp()
 {
    ADAR1000_AGC agc;
+    agc.enabled = true;  // default is OFF; enable for this test
    agc.max_gain = 32;
    agc.agc_base_gain = 31;
    agc.gain_step_up = 2;
@@ -226,6 +231,7 @@ static void test_apply_gain_spi()
 static void test_reset_preserves_config()
 {
    ADAR1000_AGC agc;
+    agc.enabled = true;  // default is OFF; enable for this test
    agc.agc_base_gain = 42;
    agc.gain_step_down = 8;
    agc.cal_offset[3] = -5;
@@ -255,6 +261,7 @@ static void test_reset_preserves_config()
 static void test_saturation_counter()
 {
    ADAR1000_AGC agc;
+    agc.enabled = true;  // default is OFF; enable for this test

    for (int i = 0; i < 10; ++i) {
        agc.update(true);
@@ -274,6 +281,7 @@ static void test_saturation_counter()
 static void test_mixed_sequence()
 {
    ADAR1000_AGC agc;
+    agc.enabled = true;  // default is OFF; enable for this test
    agc.agc_base_gain = 30;
    agc.gain_step_down = 4;
    agc.gain_step_up = 1;
@@ -0,0 +1,853 @@
+/*******************************************************************************
+ * test_um982_gps.c -- Unit tests for UM982 GPS driver
+ *
+ * Tests NMEA parsing, checksum validation, coordinate parsing, init sequence,
+ * and validity tracking. Uses the mock HAL infrastructure for UART.
+ *
+ * Build: see Makefile target test_um982_gps
+ * Run:   ./test_um982_gps
+ ******************************************************************************/
+#include "stm32_hal_mock.h"
+#include "../9_1_3_C_Cpp_Code/um982_gps.h"
+#include "../9_1_3_C_Cpp_Code/um982_gps.c"  /* Include .c directly for white-box testing */
+
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include <math.h>
+
+/* ========================= Test helpers ============================== */
+
+static int tests_passed = 0;
+static int tests_failed = 0;
+
+#define TEST(name) \
+    do { printf("  [TEST] %-55s ", name); } while(0)
+
+#define PASS() \
+    do { printf("PASS\n"); tests_passed++; } while(0)
+
+#define FAIL(msg) \
+    do { printf("FAIL: %s\n", msg); tests_failed++; } while(0)
+
+#define ASSERT_TRUE(expr, msg) \
+    do { if (!(expr)) { FAIL(msg); return; } } while(0)
+
+#define ASSERT_FALSE(expr, msg) \
+    do { if (expr) { FAIL(msg); return; } } while(0)
+
+#define ASSERT_EQ_INT(a, b, msg) \
+    do { if ((a) != (b)) { \
+        char _buf[256]; \
+        snprintf(_buf, sizeof(_buf), "%s (got %d, expected %d)", msg, (int)(a), (int)(b)); \
+        FAIL(_buf); return; \
+    } } while(0)
+
+#define ASSERT_NEAR(a, b, tol, msg) \
+    do { if (fabs((double)(a) - (double)(b)) > (tol)) { \
+        char _buf[256]; \
+        snprintf(_buf, sizeof(_buf), "%s (got %.8f, expected %.8f)", msg, (double)(a), (double)(b)); \
+        FAIL(_buf); return; \
+    } } while(0)
+
+#define ASSERT_NAN(val, msg) \
+    do { if (!isnan(val)) { FAIL(msg); return; } } while(0)
+
+static UM982_GPS_t gps;
+
+static void reset_gps(void)
+{
+    spy_reset();
+    memset(&gps, 0, sizeof(gps));
+    gps.huart = &huart5;
+    gps.heading = NAN;
+    gps.heading_mode = 'V';
+    gps.rmc_status = 'V';
+}
+
+/* ========================= Checksum tests ============================ */
+
+static void test_checksum_valid(void)
+{
+    TEST("checksum: valid GGA");
+    ASSERT_TRUE(um982_verify_checksum(
+        "$GNGGA,001043.00,4404.14036,N,12118.85961,W,1,12,0.98,1113.0,M,-21.3,M*47"),
+        "should be valid");
+    PASS();
+}
+
+static void test_checksum_valid_ths(void)
+{
+    TEST("checksum: valid THS");
+    ASSERT_TRUE(um982_verify_checksum("$GNTHS,341.3344,A*1F"),
+        "should be valid");
+    PASS();
+}
+
+static void test_checksum_invalid(void)
+{
+    TEST("checksum: invalid (wrong value)");
+    ASSERT_FALSE(um982_verify_checksum("$GNTHS,341.3344,A*FF"),
+        "should be invalid");
+    PASS();
+}
+
+static void test_checksum_missing_star(void)
+{
+    TEST("checksum: missing * marker");
+    ASSERT_FALSE(um982_verify_checksum("$GNTHS,341.3344,A"),
+        "should be invalid");
+    PASS();
+}
+
+static void test_checksum_null(void)
+{
+    TEST("checksum: NULL input");
+    ASSERT_FALSE(um982_verify_checksum(NULL), "should be false");
+    PASS();
+}
+
+static void test_checksum_no_dollar(void)
+{
+    TEST("checksum: missing $ prefix");
+    ASSERT_FALSE(um982_verify_checksum("GNTHS,341.3344,A*1F"),
+        "should be invalid without $");
+    PASS();
+}
+
+/* ========================= Coordinate parsing tests ================== */
+
+static void test_coord_latitude_north(void)
+{
+    TEST("coord: latitude 4404.14036 N");
+    double lat = um982_parse_coord("4404.14036", 'N');
+    /* 44 + 04.14036/60 = 44.069006 */
+    ASSERT_NEAR(lat, 44.069006, 0.000001, "latitude");
+    PASS();
+}
+
+static void test_coord_latitude_south(void)
+{
+    TEST("coord: latitude 3358.92500 S (negative)");
+    double lat = um982_parse_coord("3358.92500", 'S');
+    ASSERT_TRUE(lat < 0.0, "should be negative for S");
+    ASSERT_NEAR(lat, -(33.0 + 58.925/60.0), 0.000001, "latitude");
+    PASS();
+}
+
+static void test_coord_longitude_3digit(void)
+{
+    TEST("coord: longitude 12118.85961 W (3-digit degrees)");
+    double lon = um982_parse_coord("12118.85961", 'W');
+    /* 121 + 18.85961/60 = 121.314327 */
+    ASSERT_TRUE(lon < 0.0, "should be negative for W");
+    ASSERT_NEAR(lon, -(121.0 + 18.85961/60.0), 0.000001, "longitude");
+    PASS();
+}
+
+static void test_coord_longitude_east(void)
+{
+    TEST("coord: longitude 11614.19729 E");
+    double lon = um982_parse_coord("11614.19729", 'E');
+    ASSERT_TRUE(lon > 0.0, "should be positive for E");
+    ASSERT_NEAR(lon, 116.0 + 14.19729/60.0, 0.000001, "longitude");
+    PASS();
+}
+
+static void test_coord_empty(void)
+{
+    TEST("coord: empty string returns NAN");
+    ASSERT_NAN(um982_parse_coord("", 'N'), "should be NAN");
+    PASS();
+}
+
+static void test_coord_null(void)
+{
+    TEST("coord: NULL returns NAN");
+    ASSERT_NAN(um982_parse_coord(NULL, 'N'), "should be NAN");
+    PASS();
+}
+
+static void test_coord_no_dot(void)
+{
+    TEST("coord: no decimal point returns NAN");
+    ASSERT_NAN(um982_parse_coord("440414036", 'N'), "should be NAN");
+    PASS();
+}
+
+/* ========================= GGA parsing tests ========================= */
+
+static void test_parse_gga_full(void)
+{
+    TEST("GGA: full sentence with all fields");
+    reset_gps();
+    mock_set_tick(1000);
+
+    um982_parse_sentence(&gps,
+        "$GNGGA,001043.00,4404.14036,N,12118.85961,W,1,12,0.98,1113.0,M,-21.3,M*47");
+
+    ASSERT_NEAR(gps.latitude, 44.069006, 0.0001, "latitude");
+    ASSERT_NEAR(gps.longitude, -(121.0 + 18.85961/60.0), 0.0001, "longitude");
+    ASSERT_EQ_INT(gps.fix_quality, 1, "fix quality");
+    ASSERT_EQ_INT(gps.num_satellites, 12, "num sats");
+    ASSERT_NEAR(gps.hdop, 0.98, 0.01, "hdop");
+    ASSERT_NEAR(gps.altitude, 1113.0, 0.1, "altitude");
+    ASSERT_NEAR(gps.geoid_sep, -21.3, 0.1, "geoid sep");
+    PASS();
+}
+
+static void test_parse_gga_rtk_fixed(void)
+{
+    TEST("GGA: RTK fixed (quality=4)");
+    reset_gps();
+
+    um982_parse_sentence(&gps,
+        "$GNGGA,023634.00,4004.73871635,N,11614.19729418,E,4,28,0.7,61.0988,M,-8.4923,M,,*5D");
+
+    ASSERT_EQ_INT(gps.fix_quality, 4, "RTK fixed");
+    ASSERT_EQ_INT(gps.num_satellites, 28, "num sats");
+    ASSERT_NEAR(gps.latitude, 40.0 + 4.73871635/60.0, 0.0000001, "latitude");
+    ASSERT_NEAR(gps.longitude, 116.0 + 14.19729418/60.0, 0.0000001, "longitude");
+    PASS();
+}
+
+static void test_parse_gga_no_fix(void)
+{
+    TEST("GGA: no fix (quality=0)");
+    reset_gps();
+
+    /* Compute checksum for this sentence */
+    um982_parse_sentence(&gps,
+        "$GNGGA,235959.00,,,,,0,00,99.99,,,,,,*79");
+
+    ASSERT_EQ_INT(gps.fix_quality, 0, "no fix");
+    PASS();
+}
+
+/* ========================= RMC parsing tests ========================= */
+
+static void test_parse_rmc_valid(void)
+{
+    TEST("RMC: valid position and speed");
+    reset_gps();
+    mock_set_tick(2000);
+
+    um982_parse_sentence(&gps,
+        "$GNRMC,001031.00,A,4404.13993,N,12118.86023,W,0.146,,100117,,,A*7B");
+
+    ASSERT_EQ_INT(gps.rmc_status, 'A', "status");
+    ASSERT_NEAR(gps.latitude, 44.0 + 4.13993/60.0, 0.0001, "latitude");
+    ASSERT_NEAR(gps.longitude, -(121.0 + 18.86023/60.0), 0.0001, "longitude");
+    ASSERT_NEAR(gps.speed_knots, 0.146, 0.001, "speed");
+    PASS();
+}
+
+static void test_parse_rmc_void(void)
+{
+    TEST("RMC: void status (no valid fix)");
+    reset_gps();
+    gps.latitude = 12.34;  /* Pre-set to check it doesn't get overwritten */
+
+    um982_parse_sentence(&gps,
+        "$GNRMC,235959.00,V,,,,,,,100117,,,N*64");
+
+    ASSERT_EQ_INT(gps.rmc_status, 'V', "void status");
+    ASSERT_NEAR(gps.latitude, 12.34, 0.001, "lat should not change on void");
+    PASS();
+}
+
+/* ========================= THS parsing tests ========================= */
+
+static void test_parse_ths_autonomous(void)
+{
+    TEST("THS: autonomous heading 341.3344");
+    reset_gps();
+    mock_set_tick(3000);
+
+    um982_parse_sentence(&gps, "$GNTHS,341.3344,A*1F");
+
+    ASSERT_NEAR(gps.heading, 341.3344, 0.001, "heading");
+    ASSERT_EQ_INT(gps.heading_mode, 'A', "mode");
+    PASS();
+}
+
+static void test_parse_ths_not_valid(void)
+{
+    TEST("THS: not valid mode");
+    reset_gps();
+
+    um982_parse_sentence(&gps, "$GNTHS,,V*10");
+
+    ASSERT_NAN(gps.heading, "heading should be NAN when empty");
+    ASSERT_EQ_INT(gps.heading_mode, 'V', "mode V");
+    PASS();
+}
+
+static void test_parse_ths_zero(void)
+{
+    TEST("THS: heading exactly 0.0000");
+    reset_gps();
+
+    um982_parse_sentence(&gps, "$GNTHS,0.0000,A*19");
+
+    ASSERT_NEAR(gps.heading, 0.0, 0.001, "heading zero");
+    ASSERT_EQ_INT(gps.heading_mode, 'A', "mode A");
+    PASS();
+}
+
+static void test_parse_ths_360_boundary(void)
+{
+    TEST("THS: heading near 360");
+    reset_gps();
+
+    um982_parse_sentence(&gps, "$GNTHS,359.9999,D*13");
+
+    ASSERT_NEAR(gps.heading, 359.9999, 0.001, "heading near 360");
+    ASSERT_EQ_INT(gps.heading_mode, 'D', "mode D");
+    PASS();
+}
+
+/* ========================= VTG parsing tests ========================= */
+
+static void test_parse_vtg(void)
+{
+    TEST("VTG: course and speed");
+    reset_gps();
+
+    um982_parse_sentence(&gps,
+        "$GPVTG,220.86,T,,M,2.550,N,4.724,K,A*34");
+
+    ASSERT_NEAR(gps.course_true, 220.86, 0.01, "course");
+    ASSERT_NEAR(gps.speed_knots, 2.550, 0.001, "speed knots");
+    ASSERT_NEAR(gps.speed_kmh, 4.724, 0.001, "speed kmh");
+    PASS();
+}
+
+/* ========================= Talker ID tests =========================== */
+
+static void test_talker_gp(void)
+{
+    TEST("talker: GP prefix parses correctly");
+    reset_gps();
+
+    um982_parse_sentence(&gps, "$GPTHS,123.4567,A*07");
+
+    ASSERT_NEAR(gps.heading, 123.4567, 0.001, "heading with GP");
+    PASS();
+}
+
+static void test_talker_gl(void)
+{
+    TEST("talker: GL prefix parses correctly");
+    reset_gps();
+
+    um982_parse_sentence(&gps, "$GLTHS,123.4567,A*1B");
+
+    ASSERT_NEAR(gps.heading, 123.4567, 0.001, "heading with GL");
+    PASS();
+}
+
+/* ========================= Feed / line assembly tests ================ */
+
+static void test_feed_single_sentence(void)
+{
+    TEST("feed: single complete sentence with CRLF");
+    reset_gps();
+    mock_set_tick(5000);
+
+    const char *data = "$GNTHS,341.3344,A*1F\r\n";
+    um982_feed(&gps, (const uint8_t *)data, (uint16_t)strlen(data));
+
+    ASSERT_NEAR(gps.heading, 341.3344, 0.001, "heading");
+    PASS();
+}
+
+static void test_feed_multiple_sentences(void)
+{
+    TEST("feed: multiple sentences in one chunk");
+    reset_gps();
+    mock_set_tick(5000);
+
+    const char *data =
+        "$GNTHS,100.0000,A*18\r\n"
+        "$GNGGA,001043.00,4404.14036,N,12118.85961,W,1,12,0.98,1113.0,M,-21.3,M*47\r\n";
+    um982_feed(&gps, (const uint8_t *)data, (uint16_t)strlen(data));
+
+    ASSERT_NEAR(gps.heading, 100.0, 0.01, "heading from THS");
+    ASSERT_EQ_INT(gps.fix_quality, 1, "fix from GGA");
+    PASS();
+}
+
+static void test_feed_partial_then_complete(void)
+{
+    TEST("feed: partial bytes then complete");
+    reset_gps();
+    mock_set_tick(5000);
+
+    const char *part1 = "$GNTHS,200.";
+    const char *part2 = "5000,A*1E\r\n";
+    um982_feed(&gps, (const uint8_t *)part1, (uint16_t)strlen(part1));
+    /* Heading should not be set yet */
+    ASSERT_NAN(gps.heading, "should be NAN before complete");
+
+    um982_feed(&gps, (const uint8_t *)part2, (uint16_t)strlen(part2));
+    ASSERT_NEAR(gps.heading, 200.5, 0.01, "heading after complete");
+    PASS();
+}
+
+static void test_feed_bad_checksum_rejected(void)
+{
+    TEST("feed: bad checksum sentence is rejected");
+    reset_gps();
+    mock_set_tick(5000);
+
+    const char *data = "$GNTHS,999.0000,A*FF\r\n";
+    um982_feed(&gps, (const uint8_t *)data, (uint16_t)strlen(data));
+
+    ASSERT_NAN(gps.heading, "heading should remain NAN");
+    PASS();
+}
+
+static void test_feed_versiona_response(void)
+{
+    TEST("feed: VERSIONA response sets flag");
+    reset_gps();
+
+    const char *data = "#VERSIONA,79,GPS,FINE,2326,378237000,15434,0,18,889;\"UM982\"\r\n";
+    um982_feed(&gps, (const uint8_t *)data, (uint16_t)strlen(data));
+
+    ASSERT_TRUE(gps.version_received, "version_received should be true");
+    ASSERT_TRUE(gps.initialized, "VERSIONA should mark communication alive");
+    PASS();
+}
+
+/* ========================= Validity / age tests ====================== */
+
+static void test_heading_valid_within_timeout(void)
+{
+    TEST("validity: heading valid within timeout");
+    reset_gps();
+    mock_set_tick(10000);
+
+    um982_parse_sentence(&gps, "$GNTHS,341.3344,A*1F");
+
+    /* Still at tick 10000 */
+    ASSERT_TRUE(um982_is_heading_valid(&gps), "should be valid");
+    PASS();
+}
+
+static void test_heading_invalid_after_timeout(void)
+{
+    TEST("validity: heading invalid after 2s timeout");
+    reset_gps();
+    mock_set_tick(10000);
+
+    um982_parse_sentence(&gps, "$GNTHS,341.3344,A*1F");
+
+    /* Advance past timeout */
+    mock_set_tick(12500);
+    ASSERT_FALSE(um982_is_heading_valid(&gps), "should be invalid after 2.5s");
+    PASS();
+}
+
+static void test_heading_invalid_mode_v(void)
+{
+    TEST("validity: heading invalid with mode V");
+    reset_gps();
+    mock_set_tick(10000);
+
+    um982_parse_sentence(&gps, "$GNTHS,,V*10");
+
+    ASSERT_FALSE(um982_is_heading_valid(&gps), "mode V is invalid");
+    PASS();
+}
+
+static void test_position_valid(void)
+{
+    TEST("validity: position valid with fix quality 1");
+    reset_gps();
+    mock_set_tick(10000);
+
+    um982_parse_sentence(&gps,
+        "$GNGGA,001043.00,4404.14036,N,12118.85961,W,1,12,0.98,1113.0,M,-21.3,M*47");
+
+    ASSERT_TRUE(um982_is_position_valid(&gps), "should be valid");
+    PASS();
+}
+
+static void test_position_invalid_no_fix(void)
+{
+    TEST("validity: position invalid with no fix");
+    reset_gps();
+    mock_set_tick(10000);
+
+    um982_parse_sentence(&gps,
+        "$GNGGA,235959.00,,,,,0,00,99.99,,,,,,*79");
+
+    ASSERT_FALSE(um982_is_position_valid(&gps), "no fix = invalid");
+    PASS();
+}
+
+static void test_position_age_uses_last_valid_fix(void)
+{
+    TEST("age: position age uses last valid fix, not no-fix GGA");
+    reset_gps();
+
+    mock_set_tick(10000);
+    um982_parse_sentence(&gps,
+        "$GNGGA,001043.00,4404.14036,N,12118.85961,W,1,12,0.98,1113.0,M,-21.3,M*47");
+
+    mock_set_tick(12000);
+    um982_parse_sentence(&gps,
+        "$GNGGA,235959.00,,,,,0,00,99.99,,,,,,*79");
+
+    mock_set_tick(12500);
+    ASSERT_EQ_INT(um982_position_age(&gps), 2500, "age should still be from last valid fix");
+    ASSERT_FALSE(um982_is_position_valid(&gps), "latest no-fix GGA should invalidate position");
+    PASS();
+}
+
+static void test_heading_age(void)
+{
+    TEST("age: heading age computed correctly");
+    reset_gps();
+    mock_set_tick(10000);
+
+    um982_parse_sentence(&gps, "$GNTHS,341.3344,A*1F");
+
+    mock_set_tick(10500);
+    uint32_t age = um982_heading_age(&gps);
+    ASSERT_EQ_INT(age, 500, "age should be 500ms");
+    PASS();
+}
+
+/* ========================= Send command tests ======================== */
+
+static void test_send_command_appends_crlf(void)
+{
+    TEST("send_command: appends \\r\\n");
+    reset_gps();
+
+    um982_send_command(&gps, "GPGGA COM2 1");
+
+    /* Check that TX buffer contains "GPGGA COM2 1\r\n" */
+    const char *expected = "GPGGA COM2 1\r\n";
+    ASSERT_TRUE(mock_uart_tx_len == strlen(expected), "TX length");
+    ASSERT_TRUE(memcmp(mock_uart_tx_buf, expected, strlen(expected)) == 0,
+        "TX content should be 'GPGGA COM2 1\\r\\n'");
+    PASS();
+}
+
+static void test_send_command_null_safety(void)
+{
+    TEST("send_command: NULL gps returns false");
+    ASSERT_FALSE(um982_send_command(NULL, "RESET"), "should return false");
+    PASS();
+}
+
+/* ========================= Init sequence tests ======================= */
+
+static void test_init_sends_correct_commands(void)
+{
+    TEST("init: sends correct command sequence");
+    spy_reset();
+    mock_uart_tx_clear();
+
+    /* Pre-load VERSIONA response so init succeeds */
+    const char *ver_resp = "#VERSIONA,79,GPS,FINE,2326,378237000,15434,0,18,889;\"UM982\"\r\n";
+    mock_uart_rx_load(&huart5, (const uint8_t *)ver_resp, (uint16_t)strlen(ver_resp));
+
+    UM982_GPS_t init_gps;
+    bool ok = um982_init(&init_gps, &huart5, 50.0f, 3.0f);
+
+    ASSERT_TRUE(ok, "init should succeed");
+    ASSERT_TRUE(init_gps.initialized, "should be initialized");
+
+    /* Verify TX buffer contains expected commands */
+    const char *tx = (const char *)mock_uart_tx_buf;
+    ASSERT_TRUE(strstr(tx, "UNLOG\r\n") != NULL, "should send UNLOG");
+    ASSERT_TRUE(strstr(tx, "CONFIG HEADING FIXLENGTH\r\n") != NULL, "should send CONFIG HEADING");
+    ASSERT_TRUE(strstr(tx, "CONFIG HEADING LENGTH 50 3\r\n") != NULL, "should send LENGTH");
+    ASSERT_TRUE(strstr(tx, "GPGGA COM2 1\r\n") != NULL, "should enable GGA");
+    ASSERT_TRUE(strstr(tx, "GPRMC COM2 1\r\n") != NULL, "should enable RMC");
+    ASSERT_TRUE(strstr(tx, "GPTHS COM2 0.2\r\n") != NULL, "should enable THS at 5Hz");
+    ASSERT_TRUE(strstr(tx, "SAVECONFIG\r\n") == NULL, "should NOT save config (NVM wear)");
+    ASSERT_TRUE(strstr(tx, "VERSIONA\r\n") != NULL, "should query version");
+
+    /* Verify command order: UNLOG should come before GPGGA */
+    const char *unlog_pos = strstr(tx, "UNLOG\r\n");
+    const char *gpgga_pos = strstr(tx, "GPGGA COM2 1\r\n");
+    ASSERT_TRUE(unlog_pos < gpgga_pos, "UNLOG should precede GPGGA");
+
+    PASS();
+}
+
+static void test_init_no_baseline(void)
+{
+    TEST("init: baseline=0 skips LENGTH command");
+    spy_reset();
+    mock_uart_tx_clear();
+
+    const char *ver_resp = "#VERSIONA,79,GPS,FINE,2326,378237000,15434,0,18,889;\"UM982\"\r\n";
+    mock_uart_rx_load(&huart5, (const uint8_t *)ver_resp, (uint16_t)strlen(ver_resp));
+
+    UM982_GPS_t init_gps;
+    um982_init(&init_gps, &huart5, 0.0f, 0.0f);
+
+    const char *tx = (const char *)mock_uart_tx_buf;
+    ASSERT_TRUE(strstr(tx, "CONFIG HEADING LENGTH") == NULL, "should NOT send LENGTH");
+    PASS();
+}
+
+static void test_init_fails_no_version(void)
+{
+    TEST("init: fails if no VERSIONA response");
+    spy_reset();
+    mock_uart_tx_clear();
+
+    /* Don't load any RX data — init should timeout */
+    UM982_GPS_t init_gps;
+    bool ok = um982_init(&init_gps, &huart5, 50.0f, 3.0f);
+
+    ASSERT_FALSE(ok, "init should fail without version response");
+    ASSERT_FALSE(init_gps.initialized, "should not be initialized");
+    PASS();
+}
+
+static void test_nmea_traffic_sets_initialized_without_versiona(void)
+{
+    TEST("init state: supported NMEA traffic sets initialized");
+    reset_gps();
+
+    ASSERT_FALSE(gps.initialized, "should start uninitialized");
+    um982_parse_sentence(&gps, "$GNTHS,341.3344,A*1F");
+    ASSERT_TRUE(gps.initialized, "supported NMEA should mark communication alive");
+    PASS();
+}
+
+/* ========================= Edge case tests =========================== */
+
+static void test_empty_fields_handled(void)
+{
+    TEST("edge: GGA with empty lat/lon fields");
+    reset_gps();
+    gps.latitude = 99.99;
+    gps.longitude = 99.99;
+
+    /* GGA with empty position fields (no fix) */
+    um982_parse_sentence(&gps,
+        "$GNGGA,235959.00,,,,,0,00,99.99,,,,,,*79");
+
+    ASSERT_EQ_INT(gps.fix_quality, 0, "no fix");
+    /* Latitude/longitude should not be updated (fields are empty) */
+    ASSERT_NEAR(gps.latitude, 99.99, 0.01, "lat unchanged");
+    ASSERT_NEAR(gps.longitude, 99.99, 0.01, "lon unchanged");
+    PASS();
+}
+
+static void test_sentence_too_short(void)
+{
+    TEST("edge: sentence too short to have formatter");
+    reset_gps();
+    /* Should not crash */
+    um982_parse_sentence(&gps, "$GN");
+    um982_parse_sentence(&gps, "$");
+    um982_parse_sentence(&gps, "");
+    um982_parse_sentence(&gps, NULL);
+    PASS();
+}
+
+static void test_line_overflow(void)
+{
+    TEST("edge: oversized line is dropped");
+    reset_gps();
+
+    /* Create a line longer than UM982_LINE_BUF_SIZE */
+    char big[200];
+    memset(big, 'X', sizeof(big));
+    big[0] = '$';
+    big[198] = '\n';
+    big[199] = '\0';
+
+    um982_feed(&gps, (const uint8_t *)big, 199);
+    /* Should not crash, heading should still be NAN */
+    ASSERT_NAN(gps.heading, "no valid data from overflow");
+    PASS();
+}
+
+static void test_process_via_mock_uart(void)
+{
+    TEST("process: reads from mock UART RX buffer");
+    reset_gps();
+    mock_set_tick(5000);
+
+    /* Load data into mock UART RX */
+    const char *data = "$GNTHS,275.1234,D*18\r\n";
+    mock_uart_rx_load(&huart5, (const uint8_t *)data, (uint16_t)strlen(data));
+
+    /* Call process() which reads from UART */
+    um982_process(&gps);
+
+    ASSERT_NEAR(gps.heading, 275.1234, 0.001, "heading via process()");
+    ASSERT_EQ_INT(gps.heading_mode, 'D', "mode D");
+    PASS();
+}
+
+/* ========================= PR #68 bug regression tests =============== */
+
+/* These tests specifically verify the bugs found in the reverted PR #68 */
+
+static void test_regression_sentence_id_with_gn_prefix(void)
+{
+    TEST("regression: GN-prefixed GGA is correctly identified");
+    reset_gps();
+
+    /* PR #68 bug: strncmp(sentence, "GGA", 3) compared "GNG" vs "GGA" — never matched.
+     * Our fix: skip 2-char talker ID, compare at sentence+3. */
+    um982_parse_sentence(&gps,
+        "$GNGGA,001043.00,4404.14036,N,12118.85961,W,1,12,0.98,1113.0,M,-21.3,M*47");
+
+    ASSERT_EQ_INT(gps.fix_quality, 1, "GGA should parse with GN prefix");
+    ASSERT_NEAR(gps.latitude, 44.069006, 0.001, "latitude should be parsed");
+    PASS();
+}
+
+static void test_regression_longitude_3digit_degrees(void)
+{
+    TEST("regression: 3-digit longitude degrees parsed correctly");
+    reset_gps();
+
+    /* PR #68 bug: hardcoded 2-digit degrees for longitude.
+     * 12118.85961 should be 121° 18.85961' = 121.314327° */
+    um982_parse_sentence(&gps,
+        "$GNGGA,001043.00,4404.14036,N,12118.85961,W,1,12,0.98,1113.0,M,-21.3,M*47");
+
+    ASSERT_NEAR(gps.longitude, -(121.0 + 18.85961/60.0), 0.0001,
+        "longitude 121° should not be parsed as 12°");
+    ASSERT_TRUE(gps.longitude < -100.0, "longitude should be > 100 degrees");
+    PASS();
+}
+
+static void test_regression_hemisphere_no_ptr_corrupt(void)
+{
+    TEST("regression: hemisphere parsing doesn't corrupt field pointer");
+    reset_gps();
+
+    /* PR #68 bug: GGA/RMC hemisphere cases manually advanced ptr,
+     * desynchronizing from field counter. Our parser uses proper tokenizer. */
+    um982_parse_sentence(&gps,
+        "$GNGGA,001043.00,4404.14036,N,12118.85961,W,1,12,0.98,1113.0,M,-21.3,M*47");
+
+    /* After lat/lon, remaining fields should be correct */
+    ASSERT_EQ_INT(gps.num_satellites, 12, "sats after hemisphere");
+    ASSERT_NEAR(gps.hdop, 0.98, 0.01, "hdop after hemisphere");
+    ASSERT_NEAR(gps.altitude, 1113.0, 0.1, "altitude after hemisphere");
+    PASS();
+}
+
+static void test_regression_rmc_also_parsed(void)
+{
+    TEST("regression: RMC sentence is actually parsed (not dead code)");
+    reset_gps();
+
+    /* PR #68 bug: identifySentence never matched GGA/RMC, so position
+     * parsing was dead code. */
+    um982_parse_sentence(&gps,
+        "$GNRMC,001031.00,A,4404.13993,N,12118.86023,W,0.146,,100117,,,A*7B");
+
+    ASSERT_TRUE(gps.latitude > 44.0, "RMC lat should be parsed");
+    ASSERT_TRUE(gps.longitude < -121.0, "RMC lon should be parsed");
+    ASSERT_NEAR(gps.speed_knots, 0.146, 0.001, "RMC speed");
+    PASS();
+}
+
+/* ========================= Main ====================================== */
+
+int main(void)
+{
+    printf("=== UM982 GPS Driver Tests ===\n\n");
+
+    printf("--- Checksum ---\n");
+    test_checksum_valid();
+    test_checksum_valid_ths();
+    test_checksum_invalid();
+    test_checksum_missing_star();
+    test_checksum_null();
+    test_checksum_no_dollar();
+
+    printf("\n--- Coordinate Parsing ---\n");
+    test_coord_latitude_north();
+    test_coord_latitude_south();
+    test_coord_longitude_3digit();
+    test_coord_longitude_east();
+    test_coord_empty();
+    test_coord_null();
+    test_coord_no_dot();
+
+    printf("\n--- GGA Parsing ---\n");
+    test_parse_gga_full();
+    test_parse_gga_rtk_fixed();
+    test_parse_gga_no_fix();
+
+    printf("\n--- RMC Parsing ---\n");
+    test_parse_rmc_valid();
+    test_parse_rmc_void();
+
+    printf("\n--- THS Parsing ---\n");
+    test_parse_ths_autonomous();
+    test_parse_ths_not_valid();
+    test_parse_ths_zero();
+    test_parse_ths_360_boundary();
+
+    printf("\n--- VTG Parsing ---\n");
+    test_parse_vtg();
+
+    printf("\n--- Talker IDs ---\n");
+    test_talker_gp();
+    test_talker_gl();
+
+    printf("\n--- Feed / Line Assembly ---\n");
+    test_feed_single_sentence();
+    test_feed_multiple_sentences();
+    test_feed_partial_then_complete();
+    test_feed_bad_checksum_rejected();
+    test_feed_versiona_response();
+
+    printf("\n--- Validity / Age ---\n");
+    test_heading_valid_within_timeout();
+    test_heading_invalid_after_timeout();
+    test_heading_invalid_mode_v();
+    test_position_valid();
+    test_position_invalid_no_fix();
+    test_position_age_uses_last_valid_fix();
+    test_heading_age();
+
+    printf("\n--- Send Command ---\n");
+    test_send_command_appends_crlf();
+    test_send_command_null_safety();
+
+    printf("\n--- Init Sequence ---\n");
+    test_init_sends_correct_commands();
+    test_init_no_baseline();
+    test_init_fails_no_version();
+    test_nmea_traffic_sets_initialized_without_versiona();
+
+    printf("\n--- Edge Cases ---\n");
+    test_empty_fields_handled();
+    test_sentence_too_short();
+    test_line_overflow();
+    test_process_via_mock_uart();
+
+    printf("\n--- PR #68 Regression ---\n");
+    test_regression_sentence_id_with_gn_prefix();
+    test_regression_longitude_3digit_degrees();
+    test_regression_hemisphere_no_ptr_corrupt();
+    test_regression_rmc_also_parsed();
+
+    printf("\n===============================================\n");
+    printf("  Results: %d passed, %d failed (of %d total)\n",
+           tests_passed, tests_failed, tests_passed + tests_failed);
+    printf("===============================================\n");
+
+    return tests_failed > 0 ? 1 : 0;
+}
@@ -224,7 +224,7 @@ set_property IOSTANDARD LVCMOS33 [get_ports {stm32_mixers_enable}]

 # DIG_5 = H11, DIG_6 = G12, DIG_7 = H12 — FPGA→STM32 status outputs
 # DIG_5: AGC saturation flag (PD13 on STM32)
-# DIG_6: reserved (PD14)
+# DIG_6: AGC enable flag (PD14) — mirrors FPGA host_agc_enable to STM32
 # DIG_7: reserved (PD15)
 set_property PACKAGE_PIN H11 [get_ports {gpio_dig5}]
 set_property PACKAGE_PIN G12 [get_ports {gpio_dig6}]
@@ -11,8 +11,10 @@ module radar_receiver_final (
    input wire adc_dco_n,            // Data Clock Output N (400MHz LVDS)
 	 output wire adc_pwdn,
    
-    // Chirp counter from transmitter (for frame sync and matched filter)
+    // Chirp counter from transmitter (for matched filter indexing)
    input wire [5:0] chirp_counter,
+    // Frame-start pulse from transmitter (CDC-synchronized, 1 clk_100m cycle)
+    input wire tx_frame_start,
    
    output wire [31:0] doppler_output,
    output wire doppler_valid,
@@ -392,32 +394,31 @@ mti_canceller #(
    .mti_first_chirp(mti_first_chirp)
 );

-// ========== FRAME SYNC USING chirp_counter ==========
-reg [5:0] chirp_counter_prev;
+// ========== FRAME SYNC FROM TRANSMITTER ==========
+// [FPGA-001 FIXED] Use the authoritative new_chirp_frame signal from the
+// transmitter (via plfm_chirp_controller_enhanced), CDC-synchronized to
+// clk_100m in radar_system_top.  Previous code tried to derive frame
+// boundaries from chirp_counter == 0, but that counter comes from the
+// transmitter path (plfm_chirp_controller_enhanced) which does NOT wrap
+// at chirps_per_elev — it overflows to N and only wraps at 6-bit rollover
+// (64).  This caused frame pulses at half the expected rate for N=32.
+reg tx_frame_start_prev;
 reg new_frame_pulse;

 always @(posedge clk or negedge reset_n) begin
    if (!reset_n) begin
-        chirp_counter_prev <= 6'd0;
+        tx_frame_start_prev <= 1'b0;
        new_frame_pulse <= 1'b0;
    end else begin
-        // Default: no pulse
        new_frame_pulse <= 1'b0;
        
-        // Dynamic frame detection using host_chirps_per_elev.
-        // Detect frame boundary when chirp_counter changes AND is a
-        // multiple of host_chirps_per_elev (0, N, 2N, 3N, ...).
-        // Uses a modulo counter that resets at host_chirps_per_elev.
-        if (chirp_counter != chirp_counter_prev) begin
-            if (chirp_counter == 6'd0 ||
-                chirp_counter == host_chirps_per_elev ||
-                chirp_counter == {host_chirps_per_elev, 1'b0}) begin
-                new_frame_pulse <= 1'b1;
-            end
+        // Edge detect: tx_frame_start is a toggle-CDC derived pulse that
+        // may be 1 clock wide.  Capture rising edge for clean 1-cycle pulse.
+        if (tx_frame_start && !tx_frame_start_prev) begin
+            new_frame_pulse <= 1'b1;
        end
        
-        // Store previous value
-        chirp_counter_prev <= chirp_counter;
+        tx_frame_start_prev <= tx_frame_start;
    end
 end

@@ -483,14 +484,6 @@ always @(posedge clk or negedge reset_n) begin
            `endif
            chirps_in_current_frame <= 0;
        end
-        
-        // Monitor chirp counter pattern
-        if (chirp_counter != chirp_counter_prev) begin
-            `ifdef SIMULATION
-            $display("[TOP] chirp_counter: %0d ? %0d", 
-                     chirp_counter_prev, chirp_counter);
-            `endif
-        end
    end
 end

@@ -130,7 +130,7 @@ module radar_system_top (
    // FPGA→STM32 GPIO outputs (DIG_5..DIG_7 on 50T board)
    // Used by STM32 outer AGC loop to read saturation state without USB polling.
    output wire gpio_dig5,          // DIG_5 (H11→PD13): AGC saturation flag (1=clipping detected)
-    output wire gpio_dig6,          // DIG_6 (G12→PD14): reserved (tied low)
+    output wire gpio_dig6,          // DIG_6 (G12→PD14): AGC enable flag (mirrors host_agc_enable)
    output wire gpio_dig7           // DIG_7 (H12→PD15): reserved (tied low)
 );

@@ -505,6 +505,8 @@ radar_receiver_final rx_inst (
    
    // Chirp counter from transmitter (CDC-synchronized from 120 MHz domain)
    .chirp_counter(tx_current_chirp_sync),
+    // Frame-start pulse from transmitter (CDC-synchronized toggle→pulse)
+    .tx_frame_start(tx_new_chirp_frame_sync),
    
    // ADC Physical Interface
    .adc_d_p(adc_d_p),
@@ -1035,9 +1037,11 @@ assign system_status = status_reg;
 // ============================================================================
 // DIG_5: AGC saturation flag — high when per-frame saturation_count > 0.
 //        STM32 reads PD13 to detect clipping and adjust ADAR1000 VGA gain.
-// DIG_6, DIG_7: Reserved (tied low for future use).
+// DIG_6: AGC enable flag — mirrors host_agc_enable so STM32 outer-loop AGC
+//        tracks the FPGA register as single source of truth.
+// DIG_7: Reserved (tied low for future use).
 assign gpio_dig5 = (rx_agc_saturation_count != 8'd0);
-assign gpio_dig6 = 1'b0;
+assign gpio_dig6 = host_agc_enable;
 assign gpio_dig7 = 1'b0;

 // ============================================================================
@@ -291,9 +291,12 @@ class Mixer:
        Convert 8-bit unsigned ADC to 18-bit signed.
        RTL: adc_signed_w = {1'b0, adc_data, {9{1'b0}}} -
                            {1'b0, {8{1'b1}}, {9{1'b0}}} / 2
-        = (adc_data << 9) - (0xFF << 9) / 2
-        = (adc_data << 9) - (0xFF << 8)  [integer division]
-        = (adc_data << 9) - 0x7F80
+
+        Verilog '/' binds tighter than '-', so the division applies
+        only to the second concatenation:
+            {1'b0, 8'hFF, 9'b0} = 0x1FE00
+            0x1FE00 / 2 = 0xFF00 = 65280
+        Result: (adc_data << 9) - 0xFF00
        """
        adc_data_8bit = adc_data_8bit & 0xFF
        # {1'b0, adc_data, 9'b0} = adc_data << 9, zero-padded to 18 bits
@@ -290,9 +290,9 @@ def run_ddc(adc_samples):
    for n in range(n_samples):
        # ADC sign conversion: RTL does offset binary → signed 18-bit
        # adc_signed_w = {1'b0, adc_data, 9'b0} - {1'b0, 8'hFF, 9'b0}/2
-        # Simplified: center around zero, scale to 18-bit
+        # Exact: (adc_val << 9) - 0xFF00, where 0xFF00 = {1'b0,8'hFF,9'b0}/2
        adc_val = int(adc_samples[n])
-        adc_signed = (adc_val - 128) << 9  # Approximate RTL sign conversion to 18-bit
+        adc_signed = (adc_val << 9) - 0xFF00  # Exact RTL: {1'b0,adc,9'b0} - {1'b0,8'hFF,9'b0}/2
        adc_signed = saturate(adc_signed, 18)
        
        # NCO lookup (ignoring dithering for golden reference)
@@ -96,15 +96,31 @@ end
 reg [5:0] chirp_counter;
 reg mc_new_chirp_prev;

+// Frame-start pulse: mirrors the real transmitter's new_chirp_frame signal.
+// In the real system this fires on IDLE→LONG_CHIRP transitions in the chirp
+// controller.  Here we derive it from the mode controller's chirp_count
+// wrapping back to 0 (which wraps correctly at cfg_chirps_per_elev).
+reg tx_frame_start;
+reg [5:0] rmc_chirp_prev;
+
 always @(posedge clk_100m or negedge reset_n) begin
    if (!reset_n) begin
        chirp_counter <= 6'd0;
        mc_new_chirp_prev <= 1'b0;
+        tx_frame_start <= 1'b0;
+        rmc_chirp_prev <= 6'd0;
    end else begin
        mc_new_chirp_prev <= dut.mc_new_chirp;
        if (dut.mc_new_chirp != mc_new_chirp_prev) begin
            chirp_counter <= chirp_counter + 1;
        end
+        
+        // Detect when the internal mode controller's chirp_count wraps to 0
+        tx_frame_start <= 1'b0;
+        if (dut.rmc_chirp_count == 6'd0 && rmc_chirp_prev != 6'd0) begin
+            tx_frame_start <= 1'b1;
+        end
+        rmc_chirp_prev <= dut.rmc_chirp_count;
    end
 end

@@ -128,6 +144,7 @@ radar_receiver_final dut (
    .adc_pwdn(),

    .chirp_counter(chirp_counter),
+    .tx_frame_start(tx_frame_start),

    .doppler_output(doppler_output),
    .doppler_valid(doppler_valid),
@@ -0,0 +1,216 @@
+"""ADAR1000 vector-modulator ground-truth table and firmware parser.
+
+This module is a pure data + helpers library imported by the cross-layer
+test suite (`9_Firmware/tests/cross_layer/test_cross_layer_contract.py`,
+class `TestTier2Adar1000VmTableGroundTruth`). It has no CLI entry point
+and no side effects on import beyond the structural assertion on the
+table length.
+
+Ground-truth source
+-------------------
+The 128-entry `(I, Q)` byte pairs below are transcribed from the ADAR1000
+datasheet Rev. B, Tables 13-16, page 34 ("Phase Shifter Programming"),
+which is the primary normative reference. The same values appear in the
+Analog Devices Linux beamformer driver
+(`drivers/iio/beamformer/adar1000.c`, `adar1000_phase_values[]`) and were
+cross-checked against that driver as a secondary, independent
+transcription. The byte values are factual data (5-bit unsigned magnitude
+in bits[4:0], polarity bit at bit[5], bits[7:6] reserved zero); no
+copyrightable creative expression. Only the datasheet is the
+licensing-relevant source.
+
+PLFM_RADAR firmware indexing convention
+---------------------------------------
+`adarSetRxPhase` / `adarSetTxPhase` in
+`9_Firmware/9_1_Microcontroller/9_1_1_C_Cpp_Libraries/ADAR1000_Manager.cpp`
+write `VM_I[phase % 128]` and `VM_Q[phase % 128]` to the chip. Each index
+N corresponds to commanded beam phase `N * 360/128 = N * 2.8125 deg`. The
+ADI table is also on a uniform 2.8125 deg grid (verified by
+`check_uniform_2p8125_deg_step` below), so a 1:1 mapping is correct:
+PLFM index N == ADI table row N.
+"""
+
+from __future__ import annotations
+
+import re
+
+# ----------------------------------------------------------------------------
+# Ground truth: ADAR1000 datasheet Rev. B Tables 13-16 p.34
+# Each entry: (angle_int_deg, angle_frac_x10000, vm_byte_I, vm_byte_Q)
+# ----------------------------------------------------------------------------
+GROUND_TRUTH: list[tuple[int, int, int, int]] = [
+    (0, 0, 0x3F, 0x20), (2, 8125, 0x3F, 0x21), (5, 6250, 0x3F, 0x23),
+    (8, 4375, 0x3F, 0x24), (11, 2500, 0x3F, 0x26), (14, 625, 0x3E, 0x27),
+    (16, 8750, 0x3E, 0x28), (19, 6875, 0x3D, 0x2A), (22, 5000, 0x3D, 0x2B),
+    (25, 3125, 0x3C, 0x2D), (28, 1250, 0x3C, 0x2E), (30, 9375, 0x3B, 0x2F),
+    (33, 7500, 0x3A, 0x30), (36, 5625, 0x39, 0x31), (39, 3750, 0x38, 0x33),
+    (42, 1875, 0x37, 0x34), (45, 0, 0x36, 0x35), (47, 8125, 0x35, 0x36),
+    (50, 6250, 0x34, 0x37), (53, 4375, 0x33, 0x38), (56, 2500, 0x32, 0x38),
+    (59, 625, 0x30, 0x39), (61, 8750, 0x2F, 0x3A), (64, 6875, 0x2E, 0x3A),
+    (67, 5000, 0x2C, 0x3B), (70, 3125, 0x2B, 0x3C), (73, 1250, 0x2A, 0x3C),
+    (75, 9375, 0x28, 0x3C), (78, 7500, 0x27, 0x3D), (81, 5625, 0x25, 0x3D),
+    (84, 3750, 0x24, 0x3D), (87, 1875, 0x22, 0x3D), (90, 0, 0x21, 0x3D),
+    (92, 8125, 0x01, 0x3D), (95, 6250, 0x03, 0x3D), (98, 4375, 0x04, 0x3D),
+    (101, 2500, 0x06, 0x3D), (104, 625, 0x07, 0x3C), (106, 8750, 0x08, 0x3C),
+    (109, 6875, 0x0A, 0x3C), (112, 5000, 0x0B, 0x3B), (115, 3125, 0x0D, 0x3A),
+    (118, 1250, 0x0E, 0x3A), (120, 9375, 0x0F, 0x39), (123, 7500, 0x11, 0x38),
+    (126, 5625, 0x12, 0x38), (129, 3750, 0x13, 0x37), (132, 1875, 0x14, 0x36),
+    (135, 0, 0x16, 0x35), (137, 8125, 0x17, 0x34), (140, 6250, 0x18, 0x33),
+    (143, 4375, 0x19, 0x31), (146, 2500, 0x19, 0x30), (149, 625, 0x1A, 0x2F),
+    (151, 8750, 0x1B, 0x2E), (154, 6875, 0x1C, 0x2D), (157, 5000, 0x1C, 0x2B),
+    (160, 3125, 0x1D, 0x2A), (163, 1250, 0x1E, 0x28), (165, 9375, 0x1E, 0x27),
+    (168, 7500, 0x1E, 0x26), (171, 5625, 0x1F, 0x24), (174, 3750, 0x1F, 0x23),
+    (177, 1875, 0x1F, 0x21), (180, 0, 0x1F, 0x20), (182, 8125, 0x1F, 0x01),
+    (185, 6250, 0x1F, 0x03), (188, 4375, 0x1F, 0x04), (191, 2500, 0x1F, 0x06),
+    (194, 625, 0x1E, 0x07), (196, 8750, 0x1E, 0x08), (199, 6875, 0x1D, 0x0A),
+    (202, 5000, 0x1D, 0x0B), (205, 3125, 0x1C, 0x0D), (208, 1250, 0x1C, 0x0E),
+    (210, 9375, 0x1B, 0x0F), (213, 7500, 0x1A, 0x10), (216, 5625, 0x19, 0x11),
+    (219, 3750, 0x18, 0x13), (222, 1875, 0x17, 0x14), (225, 0, 0x16, 0x15),
+    (227, 8125, 0x15, 0x16), (230, 6250, 0x14, 0x17), (233, 4375, 0x13, 0x18),
+    (236, 2500, 0x12, 0x18), (239, 625, 0x10, 0x19), (241, 8750, 0x0F, 0x1A),
+    (244, 6875, 0x0E, 0x1A), (247, 5000, 0x0C, 0x1B), (250, 3125, 0x0B, 0x1C),
+    (253, 1250, 0x0A, 0x1C), (255, 9375, 0x08, 0x1C), (258, 7500, 0x07, 0x1D),
+    (261, 5625, 0x05, 0x1D), (264, 3750, 0x04, 0x1D), (267, 1875, 0x02, 0x1D),
+    (270, 0, 0x01, 0x1D), (272, 8125, 0x21, 0x1D), (275, 6250, 0x23, 0x1D),
+    (278, 4375, 0x24, 0x1D), (281, 2500, 0x26, 0x1D), (284, 625, 0x27, 0x1C),
+    (286, 8750, 0x28, 0x1C), (289, 6875, 0x2A, 0x1C), (292, 5000, 0x2B, 0x1B),
+    (295, 3125, 0x2D, 0x1A), (298, 1250, 0x2E, 0x1A), (300, 9375, 0x2F, 0x19),
+    (303, 7500, 0x31, 0x18), (306, 5625, 0x32, 0x18), (309, 3750, 0x33, 0x17),
+    (312, 1875, 0x34, 0x16), (315, 0, 0x36, 0x15), (317, 8125, 0x37, 0x14),
+    (320, 6250, 0x38, 0x13), (323, 4375, 0x39, 0x11), (326, 2500, 0x39, 0x10),
+    (329, 625, 0x3A, 0x0F), (331, 8750, 0x3B, 0x0E), (334, 6875, 0x3C, 0x0D),
+    (337, 5000, 0x3C, 0x0B), (340, 3125, 0x3D, 0x0A), (343, 1250, 0x3E, 0x08),
+    (345, 9375, 0x3E, 0x07), (348, 7500, 0x3E, 0x06), (351, 5625, 0x3F, 0x04),
+    (354, 3750, 0x3F, 0x03), (357, 1875, 0x3F, 0x01),
+]
+
+assert len(GROUND_TRUTH) == 128, f"GROUND_TRUTH must have 128 entries, has {len(GROUND_TRUTH)}"
+
+VM_I_REF: list[int] = [row[2] for row in GROUND_TRUTH]
+VM_Q_REF: list[int] = [row[3] for row in GROUND_TRUTH]
+
+
+# ----------------------------------------------------------------------------
+# Structural-invariant checks on the embedded ground-truth transcription.
+# These defend against typos during the copy-paste from the datasheet / ADI
+# driver. Each function returns a list of error strings (empty == pass) so
+# callers (the pytest class) can assert-on-empty with a useful message.
+# ----------------------------------------------------------------------------
+def check_byte_format(label: str, table: list[int]) -> list[str]:
+    """Each byte must have bits[7:6] == 0 (reserved)."""
+    errors = []
+    for i, byte in enumerate(table):
+        if byte & 0xC0:
+            errors.append(f"{label}[{i}]=0x{byte:02X}: reserved bits[7:6] non-zero")
+    return errors
+
+
+def check_uniform_2p8125_deg_step() -> list[str]:
+    """Angles must form a uniform 2.8125 deg grid: angle[N] == N * 2.8125."""
+    errors = []
+    for i, (deg_int, deg_frac, _, _) in enumerate(GROUND_TRUTH):
+        # angle in units of 1/10000 degree; 2.8125 deg = 28125/10000 exactly
+        angle_e4 = deg_int * 10000 + deg_frac
+        expected_e4 = i * 28125
+        if angle_e4 != expected_e4:
+            errors.append(
+                f"GROUND_TRUTH[{i}]: angle {deg_int}.{deg_frac:04d} deg "
+                f"(={angle_e4}/10000) != expected {expected_e4}/10000 "
+                f"(=i*2.8125)"
+            )
+    return errors
+
+
+def check_quadrant_symmetry() -> list[str]:
+    """Angle and angle+180 deg must have inverted polarity bits but identical
+    magnitudes. Index offset 64 corresponds to 180 deg on the 128-step grid.
+
+    Exemption: when magnitude is zero the polarity bit is physically
+    meaningless (sign of zero is undefined for the IQ phasor projection).
+    The datasheet uses POL=1 for both 0 and 180 deg Q components (both
+    encode Q=0). Skip the polarity assertion for zero-magnitude entries.
+    """
+    errors = []
+    POL = 0x20
+    MAG = 0x1F
+    for i in range(64):
+        j = i + 64
+        mag_i_a, mag_i_b = VM_I_REF[i] & MAG, VM_I_REF[j] & MAG
+        if mag_i_a != mag_i_b:
+            errors.append(
+                f"VM_I[{i}]=0x{VM_I_REF[i]:02X} vs VM_I[{j}]=0x{VM_I_REF[j]:02X}: "
+                f"180 deg pair has different magnitude"
+            )
+        if mag_i_a != 0 and (VM_I_REF[i] & POL) == (VM_I_REF[j] & POL):
+            errors.append(
+                f"VM_I[{i}]=0x{VM_I_REF[i]:02X} vs VM_I[{j}]=0x{VM_I_REF[j]:02X}: "
+                f"180 deg pair has same polarity (should be inverted, mag={mag_i_a})"
+            )
+        mag_q_a, mag_q_b = VM_Q_REF[i] & MAG, VM_Q_REF[j] & MAG
+        if mag_q_a != mag_q_b:
+            errors.append(
+                f"VM_Q[{i}]=0x{VM_Q_REF[i]:02X} vs VM_Q[{j}]=0x{VM_Q_REF[j]:02X}: "
+                f"180 deg pair has different magnitude"
+            )
+        if mag_q_a != 0 and (VM_Q_REF[i] & POL) == (VM_Q_REF[j] & POL):
+            errors.append(
+                f"VM_Q[{i}]=0x{VM_Q_REF[i]:02X} vs VM_Q[{j}]=0x{VM_Q_REF[j]:02X}: "
+                f"180 deg pair has same polarity (should be inverted, mag={mag_q_a})"
+            )
+    return errors
+
+
+def check_cardinal_points() -> list[str]:
+    """Spot-check cardinal phase points against datasheet expectations."""
+    errors = []
+    expectations = [
+        (0,  0x3F, 0x20, "0 deg: max +I, ~zero Q"),
+        (32, 0x21, 0x3D, "90 deg: ~zero I, max +Q"),
+        (64, 0x1F, 0x20, "180 deg: max -I, ~zero Q"),
+        (96, 0x01, 0x1D, "270 deg: ~zero I, max -Q"),
+    ]
+    for idx, exp_i, exp_q, desc in expectations:
+        if VM_I_REF[idx] != exp_i or VM_Q_REF[idx] != exp_q:
+            errors.append(
+                f"index {idx} ({desc}): expected (0x{exp_i:02X}, 0x{exp_q:02X}), "
+                f"got (0x{VM_I_REF[idx]:02X}, 0x{VM_Q_REF[idx]:02X})"
+            )
+    return errors
+
+
+# ----------------------------------------------------------------------------
+# Parse VM_I[] / VM_Q[] from firmware C++ source.
+# ----------------------------------------------------------------------------
+ARRAY_RE = re.compile(
+    r"const\s+uint8_t\s+ADAR1000Manager::(?P<name>VM_I|VM_Q|VM_GAIN)\s*"
+    r"\[\s*128\s*\]\s*=\s*\{(?P<body>[^}]*)\}\s*;",
+    re.DOTALL,
+)
+HEX_RE = re.compile(r"0[xX][0-9a-fA-F]{1,2}")
+
+
+def parse_array(source: str, name: str) -> list[int] | None:
+    """Extract a 128-entry uint8_t array from C++ source by name.
+
+    Returns None if the array is not found. Returns a list (possibly shorter
+    than 128) of the parsed bytes if found; caller is responsible for length
+    validation.
+
+    LIMITATION (intentional, see PR fix/adar1000-vm-tables review finding #2):
+    ARRAY_RE uses `[^}]*` for the body, which terminates at the first `}`.
+    This is sufficient for the *flat* `const uint8_t NAME[128] = { ... };`
+    declarations VM_I/VM_Q use today, but it would mis-parse if the array
+    body ever contained nested braces (e.g. designated initialisers, struct
+    aggregates, or macro-expansions producing braces). If the firmware ever
+    needs such a form for the VM tables, replace ARRAY_RE with a balanced
+    brace-counting parser. Until then, the current regex is preferred for
+    its simplicity and the round-trip tests will catch any silent breakage.
+    """
+    for m in ARRAY_RE.finditer(source):
+        if m.group("name") != name:
+            continue
+        body = m.group("body")
+        body = re.sub(r"//[^\n]*", "", body)
+        body = re.sub(r"/\*.*?\*/", "", body, flags=re.DOTALL)
+        return [int(tok, 16) for tok in HEX_RE.findall(body)]
+    return None
@@ -497,6 +497,7 @@ def count_concat_bits(concat_expr: str, port_widths: dict[str, int]) -> ConcatWi
            # Unknown width — flag it
            fragments.append((part, -1))
            total = -1  # Can't compute
+            break

    return ConcatWidth(
        total_bits=total,
@@ -26,11 +26,14 @@ layers agree (because both could be wrong).

 from __future__ import annotations

+import ast
 import os
+import re
 import struct
 import subprocess
 import tempfile
 from pathlib import Path
+from typing import ClassVar

 import pytest

@@ -40,6 +43,7 @@ import sys
 THIS_DIR = Path(__file__).resolve().parent
 sys.path.insert(0, str(THIS_DIR))
 import contract_parser as cp  # noqa: E402
+import adar1000_vm_reference as adar_vm  # noqa: E402

 # Also add the GUI dir to import radar_protocol
 sys.path.insert(0, str(cp.GUI_DIR))
@@ -49,8 +53,8 @@ sys.path.insert(0, str(cp.GUI_DIR))
 # Helpers
 # ===================================================================

-IVERILOG = os.environ.get("IVERILOG", "/opt/homebrew/bin/iverilog")
-VVP = os.environ.get("VVP", "/opt/homebrew/bin/vvp")
+IVERILOG = os.environ.get("IVERILOG", "iverilog")
+VVP = os.environ.get("VVP", "vvp")
 CXX = os.environ.get("CXX", "c++")

 # Check tool availability for conditional skipping
@@ -61,6 +65,92 @@ _has_cxx = subprocess.run(
    [CXX, "--version"], capture_output=True
 ).returncode == 0

+# In CI, missing tools must be a hard failure — never silently skip.
+_in_ci = os.environ.get("GITHUB_ACTIONS") == "true"
+if _in_ci:
+    if not _has_iverilog:
+        raise RuntimeError(
+            "iverilog is required in CI but was not found. "
+            "Ensure 'apt-get install iverilog' ran and IVERILOG/VVP are on PATH."
+        )
+    if not _has_cxx:
+        raise RuntimeError(
+            "C++ compiler is required in CI but was not found. "
+            "Ensure build-essential is installed."
+        )
+
+
+def _strip_cxx_comments_and_strings(src: str) -> str:
+    """Return src with all C/C++ comments and string/char literals removed.
+
+    Tokenising state machine with four states:
+      * CODE              — default; watches for `"`, `'`, `//`, `/*`
+      * STRING ("...")    — handles `\\"` and `\\\\` escapes
+      * CHAR   ('...')    — handles `\\'` and `\\\\` escapes
+      * LINE_COMMENT      — until next `\\n`
+      * BLOCK_COMMENT     — until next `*/`
+
+    Used by test_vm_gain_table_is_not_reintroduced to ensure the substring
+    "VM_GAIN" appearing only inside an explanatory comment or a string
+    literal does NOT count as code reintroduction. We replace stripped
+    regions with a single space so token boundaries (and line counts, by
+    approximation — newlines preserved) are not collapsed.
+    """
+    out: list[str] = []
+    i = 0
+    n = len(src)
+    CODE, STRING, CHAR, LINE_C, BLOCK_C = 0, 1, 2, 3, 4
+    state = CODE
+    while i < n:
+        c = src[i]
+        nxt = src[i + 1] if i + 1 < n else ""
+        if state == CODE:
+            if c == "/" and nxt == "/":
+                state = LINE_C
+                i += 2
+            elif c == "/" and nxt == "*":
+                state = BLOCK_C
+                i += 2
+            elif c == '"':
+                state = STRING
+                i += 1
+            elif c == "'":
+                state = CHAR
+                i += 1
+            else:
+                out.append(c)
+                i += 1
+        elif state == STRING:
+            if c == "\\" and i + 1 < n:
+                i += 2  # skip escape pair (handles \" and \\)
+            elif c == '"':
+                state = CODE
+                i += 1
+            else:
+                i += 1
+        elif state == CHAR:
+            if c == "\\" and i + 1 < n:
+                i += 2
+            elif c == "'":
+                state = CODE
+                i += 1
+            else:
+                i += 1
+        elif state == LINE_C:
+            if c == "\n":
+                out.append("\n")  # preserve line numbering
+                state = CODE
+            i += 1
+        elif state == BLOCK_C:
+            if c == "*" and nxt == "/":
+                state = CODE
+                i += 2
+            else:
+                if c == "\n":
+                    out.append("\n")
+                i += 1
+    return "".join(out)
+

 def _parse_hex_results(text: str) -> list[dict[str, str]]:
    """Parse space-separated hex lines from TB output files."""
@@ -355,6 +445,602 @@ class TestTier1ResetDefaults:
            )


+class TestTier1AgcCrossLayerInvariant:
+    """
+    Verify AGC enable/disable is consistent across FPGA, MCU, and GUI layers.
+
+    System-level invariant: the FPGA register host_agc_enable is the single
+    source of truth for AGC state. It propagates to MCU via DIG_6 GPIO and
+    to GUI via status word 4 bit[11]. At boot, all layers must agree AGC=OFF.
+    At runtime, the MCU must read DIG_6 every frame to sync its outer-loop AGC.
+    """
+
+    def test_fpga_dig6_drives_agc_enable(self):
+        """FPGA must drive gpio_dig6 from host_agc_enable, NOT tied low."""
+        rtl = (cp.FPGA_DIR / "radar_system_top.v").read_text()
+        # Must find: assign gpio_dig6 = host_agc_enable;
+        assert re.search(
+            r'assign\s+gpio_dig6\s*=\s*host_agc_enable\s*;', rtl
+        ), "gpio_dig6 must be driven by host_agc_enable (not tied low)"
+        # Must NOT have the old tied-low pattern
+        assert not re.search(
+            r"assign\s+gpio_dig6\s*=\s*1'b0\s*;", rtl
+        ), "gpio_dig6 must NOT be tied low — it carries AGC enable"
+
+    def test_fpga_agc_enable_boot_default_off(self):
+        """FPGA host_agc_enable must reset to 0 (AGC off at boot)."""
+        v_defaults = cp.parse_verilog_reset_defaults()
+        assert "host_agc_enable" in v_defaults, (
+            "host_agc_enable not found in reset block"
+        )
+        assert v_defaults["host_agc_enable"] == 0, (
+            f"host_agc_enable reset default is {v_defaults['host_agc_enable']}, "
+            "expected 0 (AGC off at boot)"
+        )
+
+    def test_mcu_agc_constructor_default_off(self):
+        """MCU ADAR1000_AGC constructor must default enabled=false."""
+        agc_cpp = (cp.MCU_LIB_DIR / "ADAR1000_AGC.cpp").read_text()
+        # The constructor initializer list must have enabled(false)
+        assert re.search(
+            r'enabled\s*\(\s*false\s*\)', agc_cpp
+        ), "ADAR1000_AGC constructor must initialize enabled(false)"
+        assert not re.search(
+            r'enabled\s*\(\s*true\s*\)', agc_cpp
+        ), "ADAR1000_AGC constructor must NOT initialize enabled(true)"
+
+    def test_mcu_reads_dig6_before_agc_gate(self):
+        """MCU main loop must read DIG_6 GPIO to sync outerAgc.enabled."""
+        main_cpp = (cp.MCU_CODE_DIR / "main.cpp").read_text()
+        # DIG_6 must be read via HAL_GPIO_ReadPin
+        assert re.search(
+            r'HAL_GPIO_ReadPin\s*\(\s*FPGA_DIG6', main_cpp,
+        ), "main.cpp must read DIG_6 GPIO via HAL_GPIO_ReadPin"
+        # outerAgc.enabled must be assigned from the DIG_6 reading
+        # (may be indirect via debounce variable like dig6_now)
+        assert re.search(
+            r'outerAgc\.enabled\s*=', main_cpp,
+        ), "main.cpp must assign outerAgc.enabled from DIG_6 state"
+
+    def test_boot_invariant_all_layers_agc_off(self):
+        """
+        At boot, all three layers must agree: AGC is OFF.
+        - FPGA: host_agc_enable resets to 0 -> DIG_6 low
+        - MCU: ADAR1000_AGC.enabled defaults to false
+        - GUI: reads status word 4 bit[11] = 0 -> reports MANUAL
+        """
+        # FPGA
+        v_defaults = cp.parse_verilog_reset_defaults()
+        assert v_defaults.get("host_agc_enable") == 0
+
+        # MCU
+        agc_cpp = (cp.MCU_LIB_DIR / "ADAR1000_AGC.cpp").read_text()
+        assert re.search(r'enabled\s*\(\s*false\s*\)', agc_cpp)
+
+        # GUI: status word 4 bit[11] is host_agc_enable, which resets to 0.
+        # Verify the GUI parses bit[11] of status word 4 as the AGC flag.
+        gui_py = (cp.GUI_DIR / "radar_protocol.py").read_text()
+        assert re.search(
+            r'words\[4\].*>>\s*11|status_words\[4\].*>>\s*11',
+            gui_py,
+        ), "GUI must parse AGC status from words[4] bit[11]"
+
+    def test_status_word4_agc_bit_matches_dig6_source(self):
+        """
+        Status word 4 bit[11] and DIG_6 must both derive from host_agc_enable.
+        This guarantees the GUI status display can never lie about MCU AGC state.
+        """
+        rtl = (cp.FPGA_DIR / "radar_system_top.v").read_text()
+
+        # DIG_6 driven by host_agc_enable
+        assert re.search(
+            r'assign\s+gpio_dig6\s*=\s*host_agc_enable\s*;', rtl
+        )
+
+        # Status word 4 must contain host_agc_enable (may be named
+        # status_agc_enable at the USB interface port boundary).
+        # Also verify the top-level wiring connects them.
+        usb_ft2232h = (cp.FPGA_DIR / "usb_data_interface_ft2232h.v").read_text()
+        usb_ft601 = (cp.FPGA_DIR / "usb_data_interface.v").read_text()
+
+        # USB interfaces use the port name status_agc_enable
+        found_in_ft2232h = "status_agc_enable" in usb_ft2232h
+        found_in_ft601 = "status_agc_enable" in usb_ft601
+
+        assert found_in_ft2232h or found_in_ft601, (
+            "status_agc_enable must appear in at least one USB interface's "
+            "status word to guarantee GUI status matches DIG_6"
+        )
+
+        # Verify top-level wiring: status_agc_enable port is connected
+        # to host_agc_enable (same signal that drives DIG_6)
+        assert re.search(
+            r'\.status_agc_enable\s*\(\s*host_agc_enable\s*\)', rtl
+        ), (
+            "Top-level must wire .status_agc_enable(host_agc_enable) "
+            "so status word and DIG_6 derive from the same signal"
+        )
+
+    def test_mcu_dig6_debounce_guards_enable_assignment(self):
+        """
+        MCU must apply a 2-frame confirmation debounce before mutating
+        outerAgc.enabled from DIG_6 reads. A naive assignment straight from
+        the latest GPIO sample would let a single-cycle glitch flip the AGC
+        state for one frame — defeating the debounce claim in the PR body.
+        """
+        main_cpp = (cp.MCU_CODE_DIR / "main.cpp").read_text()
+
+        # (1) Current-frame DIG_6 sample must be captured in a local variable
+        # so it can be compared against the previous-frame value.
+        now_match = re.search(
+            r'(bool|int|uint8_t)\s+(\w*dig6\w*)\s*=\s*[^;]*?'
+            r'HAL_GPIO_ReadPin\s*\(\s*FPGA_DIG6[^;]*;',
+            main_cpp,
+            re.DOTALL,
+        )
+        assert now_match, (
+            "DIG_6 read must be stored in a local variable (e.g. `dig6_now`) "
+            "so the current sample can be compared against the previous frame"
+        )
+        now_var = now_match.group(2)
+
+        # (2) Previous-frame state must persist across iterations via static
+        # storage, and must default to false (matches FPGA boot: AGC off).
+        prev_match = re.search(
+            r'static\s+(bool|int|uint8_t)\s+(\w*dig6\w*)\s*=\s*(false|0)\s*;',
+            main_cpp,
+        )
+        assert prev_match, (
+            "A static previous-frame variable (e.g. "
+            "`static bool dig6_prev = false;`) must exist, initialized to "
+            "false so the debounce starts in sync with the FPGA boot default"
+        )
+        prev_var = prev_match.group(2)
+        assert prev_var != now_var, (
+            f"Current and previous DIG_6 variables must be distinct "
+            f"(both are '{now_var}')"
+        )
+
+        # (3) outerAgc.enabled assignment must be gated by now == prev.
+        guarded_assign = re.search(
+            rf'if\s*\(\s*{now_var}\s*==\s*{prev_var}\s*\)\s*\{{[^}}]*?'
+            rf'outerAgc\.enabled\s*=\s*{now_var}\s*;',
+            main_cpp,
+            re.DOTALL,
+        )
+        assert guarded_assign, (
+            f"`outerAgc.enabled = {now_var};` must be inside "
+            f"`if ({now_var} == {prev_var}) {{ ... }}` — the confirmation "
+            "guard that absorbs single-sample GPIO glitches. A naive "
+            "assignment without this guard reintroduces the glitch bug."
+        )
+
+        # (4) Previous-frame variable must advance each frame.
+        prev_update = re.search(
+            rf'{prev_var}\s*=\s*{now_var}\s*;',
+            main_cpp,
+        )
+        assert prev_update, (
+            f"`{prev_var} = {now_var};` must run each frame so the "
+            "debounce window slides forward; without it the guard is "
+            "stuck and enable changes never confirm"
+        )
+
+
+# ===================================================================
+# ADAR1000 channel→register round-trip invariant (issue #90)
+# ===================================================================
+#
+# Ground-truth invariant crossing three system layers:
+#   Chip (datasheet) -> Driver (MCU helpers) -> Application (callers).
+#
+# For every logical element ch in {0,1,2,3} (hardware channels CH1..CH4),
+# the round-trip
+#     caller_expr(ch) --> helper_offset(channel) * stride --> base + off
+# must land on the physical register REG_CH{ch+1}_* defined in the ADI
+# ADAR1000 register map parsed from ADAR1000_Manager.h.
+#
+# Catches:
+#   * #90 channel rotation regardless of which side is fixed (caller OR helper).
+#   * Wrong stride (e.g. phase written with stride 1 instead of 2).
+#   * Bad mask (e.g. `channel & 0x07`, `channel & 0x01`).
+#   * Wrong base register in a helper.
+#   * New setter added with mismatched convention.
+#   * Caller moved to a file the test no longer scans (fails loudly).
+#
+# Cannot be defeated by:
+#   * Renaming/refactoring helper layout: the setter coverage test
+#     (`test_helper_sites_exist_for_all_setters`) catches missing parse.
+#   * Changing 0x03 to 3 or adding a named constant: the offset is
+#     evaluated symbolically via AST, not matched by regex.
+
+
+def _parse_adar_register_map(header_text):
+    """Extract `#define REG_CHn_(RX|TX)_(GAIN|PHS_I|PHS_Q)` values."""
+    regs = {}
+    for m in re.finditer(
+        r"^#define\s+(REG_CH[1-4]_(?:RX|TX)_(?:GAIN|PHS_I|PHS_Q))\s+(0x[0-9A-Fa-f]+)",
+        header_text,
+        re.MULTILINE,
+    ):
+        regs[m.group(1)] = int(m.group(2), 16)
+    return regs
+
+
+def _safe_eval_int_expr(expr, **variables):
+    """
+    Evaluate a small integer expression with +, -, *, &, |, ^, ~, <<, >>.
+    Python's & / | / ^ / ~ / << / >> have the same semantics as C for the
+    operand widths we care about here (uint8_t after the mask makes the
+    result fit in 0..3). No floating point, no function calls, no names
+    outside ``variables``.
+
+    SECURITY: ``expr`` MUST come from a trusted source -- specifically,
+    C/C++ source text under version control in this repository (e.g.
+    arguments parsed out of ``main.cpp``/``ADAR1000_AGC.cpp``).  Although
+    the AST whitelist below rejects function calls, attribute access,
+    subscripts, and any name not in ``variables``, ``eval`` is still
+    invoked on the compiled tree.  Do NOT pass user-supplied / network /
+    GUI input here.
+    """
+    tree = ast.parse(expr, mode="eval")
+    allowed = (
+        ast.Expression, ast.BinOp, ast.UnaryOp, ast.Constant,
+        ast.Name, ast.Load,
+        ast.Add, ast.Sub, ast.Mult, ast.Mod, ast.FloorDiv,
+        ast.BitAnd, ast.BitOr, ast.BitXor,
+        ast.USub, ast.UAdd, ast.Invert,
+        ast.LShift, ast.RShift,
+    )
+    for node in ast.walk(tree):
+        if not isinstance(node, allowed):
+            raise ValueError(
+                f"disallowed AST node {type(node).__name__!s} in `{expr}`"
+            )
+    return eval(
+        compile(tree, "<expr>", "eval"),
+        {"__builtins__": {}},
+        variables,
+    )
+
+
+def _extract_adar_helper_sites(manager_cpp, setter_names):
+    """
+    For each setter, locate the body of ``void ADAR1000Manager::<setter>``
+    and return a list of (setter, base_register, offset_expr_c, stride)
+    for every ``REG_CHn_XXX + <expr>`` memory-address assignment.
+    """
+    sites = []
+    for setter in setter_names:
+        m = re.search(
+            rf"void\s+ADAR1000Manager::{setter}\s*\([^)]*\)\s*\{{(.+?)^\}}",
+            manager_cpp,
+            re.MULTILINE | re.DOTALL,
+        )
+        if not m:
+            continue
+        body = m.group(1)
+        for access in re.finditer(
+            r"=\s*(REG_CH[1-4]_(?:RX|TX)_(?:GAIN|PHS_I|PHS_Q))\s*\+\s*([^;]+);",
+            body,
+        ):
+            base = access.group(1)
+            rhs = access.group(2).strip()
+            # Trailing `* <integer>` = stride multiplier (2 for phase I/Q).
+            stride_match = re.match(r"(.+?)\s*\*\s*(\d+)\s*$", rhs)
+            if stride_match:
+                offset_expr = stride_match.group(1).strip()
+                stride = int(stride_match.group(2))
+            else:
+                offset_expr = rhs
+                stride = 1
+            sites.append((setter, base, offset_expr, stride))
+    return sites
+
+
+# Method-definition line pattern: `[qualifier...] <ret-type> <Class>::<setter>(`
+# Covers: plain `void X::f(`, `inline void X::f(`, `static bool X::f(`, etc.
+_DEFN_RE = re.compile(
+    r"^\s*(?:inline\s+|static\s+|virtual\s+|constexpr\s+|explicit\s+)*"
+    r"(?:void|bool|uint\w+|int\w*|auto)\s+\S+::\w+\s*\("
+)
+
+
+def _extract_adar_caller_sites(sources, setter):
+    """
+    Find every call ``<obj>.<setter>(dev, <channel_expr>, ...)`` across
+    ``sources = [(filename, text), ...]``. Returns (filename, line_no,
+    channel_expr) for each. Skips function declarations/definitions.
+
+    Arg list up to matching `)`: restricted to a single line. All existing
+    call sites fit on one line; a future multi-line refactor would drop
+    callers from the scan, which the round-trip test surfaces loudly via
+    `assert callers` (rather than silently missing a site).
+    """
+    out = []
+    call_re = re.compile(rf"\b{setter}\s*\(([^;]*?)\)\s*;")
+    for filename, text in sources:
+        for line_no, line in enumerate(text.splitlines(), start=1):
+            # Skip method definition / declaration lines.
+            if _DEFN_RE.match(line):
+                continue
+            cm = call_re.search(line)
+            if not cm:
+                continue
+            args = _split_top_level_commas(cm.group(1))
+            if len(args) < 2:
+                continue
+            channel_expr = args[1].strip()
+            out.append((filename, line_no, channel_expr))
+    return out
+
+
+def _split_top_level_commas(text):
+    """Split on commas that sit at paren-depth 0 (ignores nested calls)."""
+    parts, depth, cur = [], 0, []
+    for ch in text:
+        if ch == "(":
+            depth += 1
+            cur.append(ch)
+        elif ch == ")":
+            depth -= 1
+            cur.append(ch)
+        elif ch == "," and depth == 0:
+            parts.append("".join(cur))
+            cur = []
+        else:
+            cur.append(ch)
+    if cur:
+        parts.append("".join(cur))
+    return parts
+
+
+class TestTier1Adar1000ChannelRegisterRoundTrip:
+    """
+    Cross-layer round-trip: caller channel expr -> helper offset formula
+    -> physical register address must equal REG_CH{ch+1}_* for every
+    caller and every ch in {0,1,2,3}.
+
+    See module-level block comment above and upstream issue #90.
+    """
+
+    _SETTERS = (
+        "adarSetRxPhase",
+        "adarSetTxPhase",
+        "adarSetRxVgaGain",
+        "adarSetTxVgaGain",
+    )
+
+    # Register base -> stride override. Parsed values of stride are
+    # trusted; this table is the independent ground truth for cross-check.
+    _EXPECTED_STRIDE: ClassVar[dict[str, int]] = {
+        "REG_CH1_RX_GAIN": 1,
+        "REG_CH1_TX_GAIN": 1,
+        "REG_CH1_RX_PHS_I": 2,
+        "REG_CH1_RX_PHS_Q": 2,
+        "REG_CH1_TX_PHS_I": 2,
+        "REG_CH1_TX_PHS_Q": 2,
+    }
+
+    @classmethod
+    def setup_class(cls):
+        cls.header_txt = (cp.MCU_LIB_DIR / "ADAR1000_Manager.h").read_text()
+        cls.manager_txt = (cp.MCU_LIB_DIR / "ADAR1000_Manager.cpp").read_text()
+        cls.reg_map = _parse_adar_register_map(cls.header_txt)
+        cls.helper_sites = _extract_adar_helper_sites(
+            cls.manager_txt, cls._SETTERS,
+        )
+        # Auto-discover every C++ TU under the MCU tree so a new caller
+        # added to e.g. a future ``ADAR1000_Calibration.cpp`` cannot
+        # silently escape the round-trip check (issue #90 reviewer note).
+        # Exclude any path containing a ``tests`` segment so this test
+        # does not parse its own fixtures.  The resulting list is
+        # deterministic (sorted) for reproducible parametrization.
+        scanned = []
+        seen = set()
+        for root in (cp.MCU_LIB_DIR, cp.MCU_CODE_DIR):
+            for path in sorted(root.rglob("*.cpp")):
+                if "tests" in path.parts:
+                    continue
+                if path in seen:
+                    continue
+                seen.add(path)
+                scanned.append((path.name, path.read_text()))
+        cls.sources = scanned
+        # Sanity: the two TUs known to call ADAR1000 setters at the time
+        # of issue #90 must be in scope.  If a future refactor renames or
+        # moves them this assert fires loudly rather than silently
+        # passing an empty round-trip.
+        scanned_names = {n for (n, _) in scanned}
+        for required in ("ADAR1000_AGC.cpp", "main.cpp", "ADAR1000_Manager.cpp"):
+            assert required in scanned_names, (
+                f"Auto-discovery missed `{required}`; check MCU_LIB_DIR / "
+                f"MCU_CODE_DIR roots in contract_parser.py."
+            )
+
+    # ---------- Tier A: chip ground truth ----------------------------
+
+    def test_register_map_gain_stride_is_one_per_channel(self):
+        """Datasheet invariant: RX/TX VGA gain registers are 1 byte apart."""
+        for kind in ("RX_GAIN", "TX_GAIN"):
+            for n in range(1, 4):
+                delta = (
+                    self.reg_map[f"REG_CH{n+1}_{kind}"]
+                    - self.reg_map[f"REG_CH{n}_{kind}"]
+                )
+                assert delta == 1, (
+                    f"ADAR1000 register map invariant broken: "
+                    f"REG_CH{n+1}_{kind} - REG_CH{n}_{kind} = {delta}, "
+                    f"datasheet says 1. Either the header was mis-edited "
+                    f"or ADI released a part with a different map."
+                )
+
+    def test_register_map_phase_stride_is_two_per_channel(self):
+        """Datasheet invariant: phase I/Q pairs occupy 2 bytes per channel."""
+        for kind in ("RX_PHS_I", "RX_PHS_Q", "TX_PHS_I", "TX_PHS_Q"):
+            for n in range(1, 4):
+                delta = (
+                    self.reg_map[f"REG_CH{n+1}_{kind}"]
+                    - self.reg_map[f"REG_CH{n}_{kind}"]
+                )
+                assert delta == 2, (
+                    f"ADAR1000 register map invariant broken: "
+                    f"REG_CH{n+1}_{kind} - REG_CH{n}_{kind} = {delta}, "
+                    f"datasheet says 2."
+                )
+
+    # ---------- Tier B: driver parses cleanly -------------------------
+
+    def test_helper_sites_exist_for_all_setters(self):
+        """Every channel-indexed setter must parse at least one register access."""
+        found = {s for (s, _, _, _) in self.helper_sites}
+        missing = set(self._SETTERS) - found
+        assert not missing, (
+            f"Helper parse failed for: {sorted(missing)}. "
+            f"Either a setter was renamed (update _SETTERS), moved out of "
+            f"ADAR1000_Manager.cpp (extend scan scope), or the register-"
+            f"access form changed beyond `REG_CHn_XXX + <expr>`. "
+            f"DO NOT weaken this test without reviewing issue #90."
+        )
+
+    def test_helper_parsed_stride_matches_datasheet(self):
+        """Parsed helper strides must match the datasheet register spacing."""
+        for setter, base, offset_expr, stride in self.helper_sites:
+            expected = self._EXPECTED_STRIDE.get(base)
+            assert expected is not None, (
+                f"{setter} writes to unrecognised base `{base}`. "
+                f"If ADI added a new channel-indexed register block, "
+                f"extend _EXPECTED_STRIDE with its datasheet stride."
+            )
+            assert stride == expected, (
+                f"{setter} helper uses stride {stride} for `{base}` "
+                f"(`{offset_expr} * {stride}`), datasheet says {expected}. "
+                f"Writes will overlap or skip channels."
+            )
+
+    # ---------- Tier C: round-trip to physical register ---------------
+
+    def test_all_callers_pass_one_based_channel(self):
+        """
+        INVARIANT: every caller's channel argument must, for ch in
+        {0,1,2,3}, evaluate to a 1-based ADI channel index in {1,2,3,4}.
+
+        The bug fixed in #90 was that helpers used ``channel & 0x03``
+        directly, so a caller passing bare ``ch`` (0..3) appeared to
+        work for ch=0..2 and silently aliased ch=3 onto CH4-then-CH1.
+        After the fix, helpers do ``(channel - 1) & 0x03`` and reject
+        ``channel < 1 || channel > 4``.  A future caller written as
+        ``adarSetRxPhase(dev, ch, ...)`` (bare 0-based) or
+        ``adarSetRxPhase(dev, 0, ...)`` (literal 0) would silently be
+        dropped by the bounds-check at runtime; this test catches it at
+        CI time instead.
+
+        The check intentionally lives one tier above the round-trip test
+        so the failure message points the reader at the API contract
+        (1-based per ADI datasheet & ADAR1000_AGC.cpp:76) rather than at
+        a register-arithmetic mismatch.
+        """
+        offenders = []
+        for setter in self._SETTERS:
+            callers = _extract_adar_caller_sites(self.sources, setter)
+            for filename, line_no, ch_expr in callers:
+                for ch in range(4):
+                    try:
+                        channel_val = _safe_eval_int_expr(ch_expr, ch=ch)
+                    except (NameError, KeyError, ValueError) as e:
+                        offenders.append(
+                            f"  - {filename}:{line_no} {setter}("
+                            f"…, `{ch_expr}`, …) -- ch={ch}: "
+                            f"unparseable ({e})"
+                        )
+                        continue
+                    if channel_val not in (1, 2, 3, 4):
+                        offenders.append(
+                            f"  - {filename}:{line_no} {setter}("
+                            f"…, `{ch_expr}`, …) -- ch={ch}: "
+                            f"channel={channel_val}, expected 1..4"
+                        )
+        assert not offenders, (
+            "ADAR1000 1-based channel API contract violated. The fix "
+            "for issue #90 requires every caller to pass channel in "
+            "{1,2,3,4} (CH1..CH4 per ADI datasheet). Bare 0-based ch "
+            "or a literal 0 will be silently dropped by the helper's "
+            "bounds check.  Offenders:\n" + "\n".join(offenders)
+        )
+
+    @pytest.mark.parametrize(
+        "setter",
+        [
+            "adarSetRxPhase",
+            "adarSetTxPhase",
+            "adarSetRxVgaGain",
+            "adarSetTxVgaGain",
+        ],
+    )
+    def test_round_trip_lands_on_intended_physical_channel(self, setter):
+        """
+        INVARIANT: for every caller of ``<setter>`` and every logical ch
+        in {0,1,2,3}, the effective register address equals
+        REG_CH{ch+1}_*. Catches #90 regardless of fix direction.
+        """
+        callers = _extract_adar_caller_sites(self.sources, setter)
+        assert callers, (
+            f"No callers of `{setter}` found. Either the test scope is "
+            f"incomplete (extend `setup_class.sources`) or the symbol was "
+            f"inlined/removed. A blind test is a dangerous test — "
+            f"investigate before weakening."
+        )
+        helpers = [
+            (b, e, s) for (nm, b, e, s) in self.helper_sites if nm == setter
+        ]
+        assert helpers, f"helper body for `{setter}` not parseable"
+
+        errors = []
+        for filename, line_no, ch_expr in callers:
+            for ch in range(4):
+                try:
+                    channel_val = _safe_eval_int_expr(ch_expr, ch=ch)
+                except (NameError, KeyError, ValueError) as e:
+                    pytest.fail(
+                        f"{filename}:{line_no}: caller channel expression "
+                        f"`{ch_expr}` uses symbol outside {{ch}} or a "
+                        f"disallowed operator ({e}). Extend "
+                        f"_safe_eval_int_expr variables or rewrite the "
+                        f"call site with a supported expression."
+                    )
+                for base_sym, offset_expr, stride in helpers:
+                    try:
+                        offset = _safe_eval_int_expr(
+                            offset_expr, channel=channel_val,
+                        )
+                    except (NameError, KeyError, ValueError) as e:
+                        pytest.fail(
+                            f"helper `{setter}` offset expr "
+                            f"`{offset_expr}` uses symbol outside "
+                            f"{{channel}} or a disallowed operator ({e}). "
+                            f"Extend _safe_eval_int_expr variables if new "
+                            f"driver state is introduced."
+                        )
+                    final = self.reg_map[base_sym] + offset * stride
+                    expected_sym = base_sym.replace("CH1", f"CH{ch + 1}")
+                    expected = self.reg_map[expected_sym]
+                    if final != expected:
+                        errors.append(
+                            f"  - {filename}:{line_no} {setter} "
+                            f"caller `{ch_expr}` | ch={ch} -> "
+                            f"channel={channel_val} -> "
+                            f"`{base_sym} + ({offset_expr})"
+                            f"{' * ' + str(stride) if stride != 1 else ''}`"
+                            f" = 0x{final:03X} "
+                            f"(expected {expected_sym} = 0x{expected:03X})"
+                        )
+        assert not errors, (
+            f"ADAR1000 channel round-trip FAILED for {setter} "
+            f"({len(errors)} mismatches) — writes routed to wrong physical "
+            f"channel. This is issue #90.\n" + "\n".join(errors)
+        )
+
+
 class TestTier1DataPacketLayout:
    """Verify data packet byte layout matches between Python and Verilog."""

@@ -468,6 +1154,204 @@ class TestTier1STM32SettingsPacket:
        assert flag == [23, 46, 158, 237], f"Start flag: {flag}"


+# ===================================================================
+# TIER 2: ADAR1000 Vector Modulator Lookup-Table Ground Truth
+# ===================================================================
+#
+# Cross-layer contract: the firmware constants
+#   ADAR1000Manager::VM_I[128] / VM_Q[128]
+# (in 9_Firmware/9_1_Microcontroller/9_1_1_C_Cpp_Libraries/ADAR1000_Manager.cpp)
+# MUST equal the byte values published in the ADAR1000 datasheet Rev. B,
+# Tables 13-16 page 34 ("Phase Shifter Programming"), on a uniform 2.8125 deg
+# grid (index N == phase N * 360/128 deg).
+#
+# Independent ground truth lives in tools/verify_adar1000_vm_tables.py
+# (transcribed from the datasheet, cross-checked against the ADI Linux
+# beamformer driver as a secondary source). This test imports that
+# reference and asserts a byte-exact match.
+#
+# Historical bug guarded against: from initial commit through PR #94 the
+# arrays shipped as empty placeholders ("// ... (same as in your original
+# file)"), so every adarSetRxPhase / adarSetTxPhase call wrote I=Q=0 and
+# beam steering was non-functional. A separate VM_GAIN[128] table was
+# declared but never read anywhere; this test also enforces its removal so
+# it cannot be reintroduced and silently shadow real bugs.
+
+class TestTier2Adar1000VmTableGroundTruth:
+    """Firmware ADAR1000 VM_I/VM_Q must match datasheet ground truth byte-exact."""
+
+    @pytest.fixture(scope="class")
+    def cpp_source(self):
+        path = (
+            cp.REPO_ROOT
+            / "9_Firmware"
+            / "9_1_Microcontroller"
+            / "9_1_1_C_Cpp_Libraries"
+            / "ADAR1000_Manager.cpp"
+        )
+        assert path.is_file(), f"Firmware source missing: {path}"
+        return path.read_text()
+
+    def test_ground_truth_table_shape(self):
+        """Sanity-check the imported reference (defends against import-path mishap)."""
+        gt = adar_vm.GROUND_TRUTH
+        assert len(gt) == 128, "Ground-truth table must have exactly 128 entries"
+        # Each row is (deg_int, deg_frac_e4, vm_i_byte, vm_q_byte)
+        for k, row in enumerate(gt):
+            assert len(row) == 4, f"Row {k} malformed: {row}"
+            assert 0 <= row[2] <= 0xFF, f"VM_I[{k}] out of byte range: {row[2]:#x}"
+            assert 0 <= row[3] <= 0xFF, f"VM_Q[{k}] out of byte range: {row[3]:#x}"
+            # Byte format: bits[7:6] reserved zero, bits[5] polarity, bits[4:0] mag
+            assert (row[2] & 0xC0) == 0, f"VM_I[{k}] reserved bits set: {row[2]:#x}"
+            assert (row[3] & 0xC0) == 0, f"VM_Q[{k}] reserved bits set: {row[3]:#x}"
+
+    def test_ground_truth_byte_format(self):
+        """Transcription self-check: every VM_I/VM_Q byte has reserved bits clear."""
+        errors = adar_vm.check_byte_format("VM_I_REF", adar_vm.VM_I_REF)
+        errors += adar_vm.check_byte_format("VM_Q_REF", adar_vm.VM_Q_REF)
+        assert not errors, (
+            "Byte-format violations in embedded GROUND_TRUTH (likely transcription "
+            "typo from ADAR1000 datasheet Tables 13-16):\n  " + "\n  ".join(errors)
+        )
+
+    def test_ground_truth_uniform_2p8125_deg_grid(self):
+        """Transcription self-check: angles form a uniform 2.8125 deg grid.
+
+        This is the assumption that lets the firmware use `VM_*[phase % 128]`
+        as a direct index (no nearest-neighbour search). If the embedded
+        angles drift off the grid, the firmware's indexing model is wrong.
+        """
+        errors = adar_vm.check_uniform_2p8125_deg_step()
+        assert not errors, (
+            "Non-uniform angle grid in GROUND_TRUTH:\n  " + "\n  ".join(errors)
+        )
+
+    def test_ground_truth_quadrant_symmetry(self):
+        """Transcription self-check: phi and phi+180 deg have same magnitude,
+        opposite polarity. Catches swapped/rotated rows in the table.
+        """
+        errors = adar_vm.check_quadrant_symmetry()
+        assert not errors, (
+            "Quadrant-symmetry violation in GROUND_TRUTH (table rows may be "
+            "transposed or mis-transcribed):\n  " + "\n  ".join(errors)
+        )
+
+    def test_ground_truth_cardinal_points(self):
+        """Transcription self-check: the four cardinal phases (0, 90, 180,
+        270 deg) match the datasheet-published extrema exactly.
+        """
+        errors = adar_vm.check_cardinal_points()
+        assert not errors, (
+            "Cardinal-point mismatch in GROUND_TRUTH vs ADAR1000 datasheet "
+            "Tables 13-16:\n  " + "\n  ".join(errors)
+        )
+
+    def test_firmware_vm_i_matches_datasheet(self, cpp_source):
+        gt = adar_vm.GROUND_TRUTH
+        firmware = adar_vm.parse_array(cpp_source, "VM_I")
+        assert firmware is not None, (
+            "Could not parse VM_I[128] from ADAR1000_Manager.cpp; "
+            "definition pattern may have drifted"
+        )
+        assert len(firmware) == 128, (
+            f"VM_I has {len(firmware)} entries, expected 128. "
+            "Empty placeholder regression — every phase write would emit I=0 "
+            "and beam steering would be silently broken."
+        )
+        mismatches = [
+            (k, firmware[k], gt[k][2])
+            for k in range(128)
+            if firmware[k] != gt[k][2]
+        ]
+        assert not mismatches, (
+            f"VM_I diverges from datasheet at {len(mismatches)} indices; "
+            f"first 5: {mismatches[:5]}"
+        )
+
+    def test_firmware_vm_q_matches_datasheet(self, cpp_source):
+        gt = adar_vm.GROUND_TRUTH
+        firmware = adar_vm.parse_array(cpp_source, "VM_Q")
+        assert firmware is not None, (
+            "Could not parse VM_Q[128] from ADAR1000_Manager.cpp; "
+            "definition pattern may have drifted"
+        )
+        assert len(firmware) == 128, (
+            f"VM_Q has {len(firmware)} entries, expected 128. "
+            "Empty placeholder regression — every phase write would emit Q=0."
+        )
+        mismatches = [
+            (k, firmware[k], gt[k][3])
+            for k in range(128)
+            if firmware[k] != gt[k][3]
+        ]
+        assert not mismatches, (
+            f"VM_Q diverges from datasheet at {len(mismatches)} indices; "
+            f"first 5: {mismatches[:5]}"
+        )
+
+    def test_vm_gain_table_is_not_reintroduced(self, cpp_source):
+        """Dead-code regression guard: VM_GAIN[128] must not exist as code.
+
+        The ADAR1000 vector modulator has no separate gain register; magnitude
+        is bits[4:0] of the I/Q bytes themselves. Per-channel VGA gain uses
+        registers CHx_RX_GAIN (0x10-0x13) / CHx_TX_GAIN (0x1C-0x1F) written
+        directly by adarSetRxVgaGain / adarSetTxVgaGain. A VM_GAIN[] array
+        was declared in early development, never populated, never read, and
+        was removed in PR fix/adar1000-vm-tables. Reintroducing it would
+        suggest (falsely) that an extra lookup is needed and could mask the
+        real signal path.
+
+        Uses a tokenising comment/string stripper so that the historical
+        explanation comment in the cpp file, as well as any string literal
+        containing the substring "VM_GAIN", does not trip the check.
+        """
+        stripped = _strip_cxx_comments_and_strings(cpp_source)
+        assert "VM_GAIN" not in stripped, (
+            "VM_GAIN symbol reappeared in ADAR1000_Manager.cpp executable code. "
+            "This array has no hardware backing and must not be reintroduced. "
+            "If you need to scale phase-state magnitude, modify VM_I/VM_Q "
+            "bits[4:0] directly per the datasheet."
+        )
+
+    def test_adversarial_corruption_is_detected(self):
+        """Adversarial self-test: a flipped byte in firmware MUST fail comparison.
+
+        Defends against silent bypass — e.g. a future refactor that mocks
+        parse_array() or compares len() only. We synthesise a corrupted cpp
+        source string, run the same parser, and assert mismatch is detected.
+        """
+        gt = adar_vm.GROUND_TRUTH
+        # Build a minimal valid-looking cpp snippet with one corrupted byte.
+        good_i = ", ".join(f"0x{gt[k][2]:02X}" for k in range(128))
+        good_q = ", ".join(f"0x{gt[k][3]:02X}" for k in range(128))
+        snippet_good = (
+            f"const uint8_t ADAR1000Manager::VM_I[128] = {{ {good_i} }};\n"
+            f"const uint8_t ADAR1000Manager::VM_Q[128] = {{ {good_q} }};\n"
+        )
+        # Sanity: the unmodified snippet must parse and match.
+        parsed_i = adar_vm.parse_array(snippet_good, "VM_I")
+        assert parsed_i is not None and len(parsed_i) == 128
+        assert all(parsed_i[k] == gt[k][2] for k in range(128)), (
+            "Self-test setup error: golden snippet does not match GROUND_TRUTH"
+        )
+        # Now flip the low bit of VM_I[42] and confirm detection.
+        corrupted_byte = gt[42][2] ^ 0x01
+        bad_i = ", ".join(
+            f"0x{(corrupted_byte if k == 42 else gt[k][2]):02X}"
+            for k in range(128)
+        )
+        snippet_bad = (
+            f"const uint8_t ADAR1000Manager::VM_I[128] = {{ {bad_i} }};\n"
+            f"const uint8_t ADAR1000Manager::VM_Q[128] = {{ {good_q} }};\n"
+        )
+        parsed_bad = adar_vm.parse_array(snippet_bad, "VM_I")
+        assert parsed_bad is not None and len(parsed_bad) == 128
+        assert parsed_bad[42] != gt[42][2], (
+            "Adversarial self-test FAILED: corrupted byte at index 42 was "
+            "not detected by parse_array. The cross-layer test is bypassable."
+        )
+
+
 # ===================================================================
 # TIER 2: Verilog Cosimulation
 # ===================================================================
@@ -68,13 +68,13 @@ The AERIS-10 main sub-systems are:
      - Clock Generator (AD9523-1)
      - 2x Frequency Synthesizers (ADF4382)
      - 4x 4-Channel Phase Shifters (ADAR1000) for RADAR pulse sequencing
-      - 2x ADS7830 ADCs (on Power Amplifier Boards) for Idq measurement
-      - 2x DAC5578 (on Power Amplifier Boards) for Vg control
-      - GPS module for GUI map centering
+      - 2x ADS7830 8-channel I²C ADCs (Main Board, U88 @ 0x48 / U89 @ 0x4A) for 16x Idq measurement, one per PA channel, each sensed through a 5 mΩ shunt on the PA board and an INA241A3 current-sense amplifier (x50) on the Main Board
+      - 2x DAC5578 8-channel I²C DACs (Main Board, U7 @ 0x48 / U69 @ 0x49) for 16x Vg control, one per PA channel; closed-loop calibrated at boot to the target Idq
+      - GPS module (UM982) for GUI map centering and per-detection position tagging
      - GY-85 IMU for pitch/roll correction of target coordinates
      - BMP180 Barometer
      - Stepper Motor
-      - 8x ADS7830 Temperature Sensors for cooling fan control
+      - 1x ADS7830 8-channel I²C ADC (Main Board, U10) reading 8 thermistors for thermal monitoring; a single GPIO (EN_DIS_COOLING) switches the cooling fans on when any channel exceeds the threshold
      - RF switches

 - **16x Power Amplifier Boards** - Used only for AERIS-10E version, featuring 10Watt QPA2962 GaN amplifier for extended range
Author	SHA1	Message	Date
Jason	27b55f37dc	Merge pull request #108 from NawfalMotii79/fix/adar1000-channel-rotation fix(adar1000): correct 1-based channel indexing in setters (issue #90)	2026-04-18 06:00:52 +03:00
Jason	582476fa0d	fix(adar1000): correct 1-based channel indexing in setters (issue #90 ) The four channel-indexed ADAR1000 setters (adarSetRxPhase, adarSetTxPhase, adarSetRxVgaGain, adarSetTxVgaGain) computed their register offset as `(channel & 0x03) * stride`, which silently aliased CH4 (channel=4 -> mask=0) onto CH1 and shifted CH1..CH3 by one. The API contract (1-based CH1..CH4) is documented in ADAR1000_AGC.cpp:76 and matches the ADI datasheet; every existing caller already passes `ch + 1`. Fix: subtract 1 before masking -- `((channel - 1) & 0x03) * stride` -- and reject `channel < 1 \|\| channel > 4` early with a DIAG message so a future stale 0-based caller fails loudly instead of writing to CH4. Adds TestTier1Adar1000ChannelRegisterRoundTrip (9 tests) which closes the loop independently of the driver: - parses the ADI register map directly from ADAR1000_Manager.h, - verifies the datasheet stride invariants (gain=1, phase=2), - auto-discovers every C++ TU under MCU_LIB_DIR / MCU_CODE_DIR so a new caller cannot silently escape the round-trip check, - asserts every caller's channel argument evaluates to {1,2,3,4} for ch in {0,1,2,3} (catches bare 0-based or literal-0 callers at CI time before the runtime bounds-check would silently drop them), - round-trips each (caller, ch) through the helper arithmetic and checks the final address equals REG_CH{ch+1}_*. Adversarially validated: reverting any one helper, all four helpers, corrupting the parsed register map, injecting a bare-ch caller, and auto-discovering a literal-0 caller in a fresh TU each cause the expected (and only the expected) test to fail. Stacked on fix/adar1000-vm-tables (PR #107).	2026-04-18 06:39:07 +05:45
Jason	7c91a3e0b9	fix(adar1000): populate VM_I/VM_Q phase tables; remove dead VM_GAIN The ADAR1000 vector-modulator I/Q lookup tables VM_I[128] and VM_Q[128] were declared but defined as empty initialiser lists since the first commit (`5fbe97f`). Every call to adarSetRxPhase / adarSetTxPhase therefore wrote (I=0x00, Q=0x00) to registers 0x21/0x23 (Rx) and 0x32/0x34 (Tx) regardless of the requested phase state, leaving beam steering completely non-functional in firmware. This commit: * Populates VM_I[128] and VM_Q[128] from ADAR1000 datasheet Rev. B Tables 13-16 (p.34) on a uniform 2.8125 deg grid (360 / 128 states). Byte format: bits[7:6] reserved 0, bit[5] polarity (1 = positive lobe), bits[4:0] 5-bit unsigned magnitude - exactly as specified. * Removes VM_GAIN[128] declaration and (empty) definition. The ADAR1000 has no separate VM gain register; per-channel VGA gain is set via CHx_RX_GAIN (0x10-0x13) / CHx_TX_GAIN (0x1C-0x1F) by adarSetRxVgaGain / adarSetTxVgaGain. VM_GAIN was never populated, never read anywhere in the firmware, and its presence falsely suggested a missing scaling step in the signal path. * Adds 9_Firmware/tests/cross_layer/adar1000_vm_reference.py: an independently-derived ground-truth module containing the full datasheet table plus byte-format / uniform-grid / quadrant-symmetry / cardinal-point invariant checkers and a tolerant C array parser. * Adds TestTier2Adar1000VmTableGroundTruth (9 tests) to test_cross_layer_contract.py, including a tokenising C/C++ comment+string stripper used by the VM_GAIN reintroduction guard, and an adversarial self-test that corrupts one byte and asserts the comparison detects it (defends against silent bypass via future fixture/parser refactors). Adversarially validated: removing the firmware definitions, flipping a single byte, or reintroducing VM_GAIN as code each cause the suite to fail; restoring causes it to pass. VM_GAIN appearing inside string literals or comments correctly does NOT trip the guard. Closes the empty-table half of the ADAR1000 phase-control bug class. The separate channel-rotation issue (#90) will be addressed in a follow-up PR. Refs: 7_Components Datasheets and Application notes/ADAR1000.pdf Rev. B Tables 13-16 p.34	2026-04-18 02:02:07 +05:45
Jason	fd6cff5b2b	Merge pull request #102 from JJassonn69/chore/sync-main-into-develop chore: sync main → develop (schematic updates + README + project doc)	2026-04-17 19:31:31 +03:00
Jason	964f1903f3	chore: sync main → develop (schematic updates, README, project doc) Brings in main-only commits that never reached develop: `754d919` Added silk screen and headers description (MainBoard .brd) `0443516` Added thermal vias (RF_PA .brd) `5fbe051` Added ABAC INDUSTRY web site (Project_Description.docx) `12b549d` / `5d5e9ff` Merge PR #101: README BOM sensor counts fix No conflicts expected: develop has not touched any of these paths.	2026-04-17 22:12:26 +05:45
Jason	12b549dafb	Merge pull request #101 from JJassonn69/fix/readme-bom-sensor-counts docs(readme): correct STM32 peripheral counts and locations to match production BOM	2026-04-17 17:21:59 +03:00
Jason	5d5e9ff297	docs(readme): correct BOM sensor counts and locations The STM32 peripheral list in the README disagreed with the production BOM (4_7_Production Files/Gerber_Main_Board/RADAR_Main_Board_BOM_csv) and with the firmware (9_1_Microcontroller/.../main.cpp). Corrections based on origin/main commit `754d919`: - ADS7830 Idq ADCs: placed on the Main Board (U88 @ 0x48, U89 @ 0x4A), not on the Power Amplifier Boards. Added the INA241A3 (x50) and 5 mOhm shunt detail that completes the current-sense chain. - DAC5578 Vg DACs: placed on the Main Board (U7 @ 0x48, U69 @ 0x49), not on the Power Amplifier Boards. Noted closed-loop Idq calibration at boot (main.cpp powerUpSequence). - Temperature sensors: 1x ADS7830 (U10) with 8 single-ended channels reading 8 thermistors -- not 8 separate ADS7830 chips. Cooling is a single GPIO (EN_DIS_COOLING), bang-bang, not PWM. - GPS: reflect the UM982 driver merged in #79 and its role in per-detection position tagging beyond map centering. Counts now match the 3x ADS7830 / 2x DAC5578 / 16x INA241A3 population in the production BOM.	2026-04-17 20:04:01 +05:45
NawfalMotii79	754d919e44	Added silk screen and headers description	2026-04-16 23:48:23 +01:00
NawfalMotii79	0443516cc9	Added thermal vias	2026-04-16 23:47:24 +01:00
NawfalMotii79	5fbe0513b5	Added ABAC INDUSTRY web site	2026-04-16 23:46:08 +01:00
Jason	c3db8a9122	Merge pull request #96 from joyshmitz/chore/remove-dead-adar1000-c-api chore(mcu): remove dead C-style adar1000 driver	2026-04-16 23:51:22 +03:00
Jason	ec8256e25a	Merge pull request #95 from joyshmitz/test/agc-debounce-enforce test(cross-layer): enforce 2-frame DIG_6 debounce guard on outerAgc.enabled (follow-up to #93)	2026-04-16 23:42:12 +03:00
Serhii	8e1b3f22d2	chore(mcu): remove dead C-style adar1000 driver The firmware uses the C++ ADAR1000_Manager class exclusively. The C-style driver pair (adar1000.c, 693 LoC; adar1000.h, 294 LoC) has no external call sites: grep -rn "Adar_Set\|Adar_Read\|Adar_Write\|Adar_Soft" 9_Firmware grep -rn "AdarDevice\|AdarBiasCurrents\|AdarDeviceInfo" 9_Firmware Both return hits only inside adar1000.c/h themselves. ADAR1000_Manager.h has its own copies of REG_CH1_, REG_INTERFACE_CONFIG_A, etc. and does not include adar1000.h. main.cpp had a lone #include "adar1000.h" but referenced no symbols from it; the REG_ macros it uses resolve through ADAR1000_Manager.h on the next line. No behaviour change: the deleted code was unreachable. Side note on #90: adar1000.c contained a second copy of the REG_CH1_* + (channel & 0x03) channel-rotation pattern tracked in #90 (lines 349, 397-398, 472, 520-521). This commit does not fix #90 -- the live path in ADAR1000_Manager.cpp still needs the channel-index fix -- but it removes the dormant copy so the bug has one less place to hide. Verification: - 9_Firmware/9_1_Microcontroller/tests: make clean && make -> all passing (51/51 UM982 GPS, 24/24 driver, 13/13 ADAR1000_AGC, bugs #1-15, Gap-3 fixes 1-5, safety fixes) - 9_Firmware/tests/cross_layer: 29 passed - grep -rn "adar1000\.h\|adar1000\.c\|Adar_\|AdarDevice" 9_Firmware: 0 hits	2026-04-16 22:12:23 +03:00
Serhii	15ae940be5	test(cross-layer): enforce 2-frame DIG_6 debounce guard on outerAgc.enabled PR #93 added a 2-frame confirmation debounce so a single-sample GPIO glitch cannot flip MCU outer-loop AGC state. The debounce is load-bearing for the "prevents a single-sample glitch" guarantee in the PR body, but no existing test enforces its structure — test_mcu_reads_dig6_before_agc_gate only checks that HAL_GPIO_ReadPin(FPGA_DIG6, ...) and `outerAgc.enabled =` appear somewhere in main.cpp, which a naive direct assignment would still pass. Add test_mcu_dig6_debounce_guards_enable_assignment to TestTier1AgcCrossLayerInvariant, verifying four structural invariants of the debounce: 1. Current DIG_6 sample captured in a local variable 2. Static previous-frame variable defaulting to false (matches FPGA boot: host_agc_enable resets 0) 3. outerAgc.enabled assignment gated by `now == prev` 4. Previous-frame variable advanced each frame Verified test fails on a naive patch that removes the guard and passes on the current PR #93 implementation. Full cross-layer suite stays at 0 failures (36/36 pass locally).	2026-04-16 21:29:37 +03:00
Jason	658752abb7	fix: propagate FPGA AGC enable to MCU outer loop via DIG_6 GPIO Resolve cross-layer AGC control mismatch where opcode 0x28 only controlled the FPGA inner-loop AGC but the STM32 outer-loop AGC (ADAR1000_AGC) ran independently with its own enable state. FPGA: Drive gpio_dig6 from host_agc_enable instead of tied low, making the FPGA register the single source of truth for AGC state. MCU: Change ADAR1000_AGC constructor default from enabled(true) to enabled(false) so boot state matches FPGA reset default (AGC off). Read DIG_6 GPIO every frame with 2-frame confirmation debounce to sync outerAgc.enabled — prevents single-sample glitch from causing spurious AGC state transitions. Tests: Update MCU unit tests for new default, add 6 cross-layer contract tests verifying the FPGA-MCU-GUI AGC invariant chain.	2026-04-17 00:04:37 +05:45
Jason	fa5e1dcdf4	Merge pull request #88 from shaun0927/fix/concat-parser-unknown-signal fix(test): break on unknown signal in count_concat_bits	2026-04-16 13:55:12 +03:00
Jason	ade1497457	Merge pull request #79 from NawfalMotii79/feat/um982-gps-driver feat: UM982 GPS driver + deferred fixes (STM32-006, STM32-004, FPGA-001)	2026-04-16 13:54:40 +03:00
Jason	f1d3bff4fe	Merge pull request #85 from shaun0927/fix/ci-iverilog-path fix(ci): use PATH-based iverilog/vvp discovery for cross-layer tests	2026-04-16 11:49:44 +03:00
Jason	791b2e7374	Merge pull request #86 from shaun0927/fix/golden-ref-adc-formula fix(cosim): align golden_reference ADC sign conversion with RTL	2026-04-16 11:49:21 +03:00
copilot-swe-agent[bot]	df875bdf4d	Merge origin/develop into feat/um982-gps-driver Co-authored-by: JJassonn69 <83615043+JJassonn69@users.noreply.github.com>	2026-04-16 06:23:05 +00:00
Jason	15a9cde274	review(cosim): fix stale comment and wrong docstring derivation golden_reference.py: update comment from 'Simplified' to 'Exact' to match shaun0927's corrected formula. fpga_model.py: fix adc_to_signed docstring that incorrectly derived 0x7F80 instead of 0xFF00. Verilog '/' binds tighter than '-', so {1'b0,8'hFF,9'b0}/2 = 0x1FE00/2 = 0xFF00, not 0xFF<<8 = 0x7F80.	2026-04-16 11:07:56 +05:45
Jason	ae7643975d	fix(ci): fail hard when required tools missing in CI Silently skipping Tier 2/3 tests in CI defeats the purpose of running them. Add a GITHUB_ACTIONS guard that raises RuntimeError at module load if iverilog or C++ compiler is not found, preventing false-green CI results from skipped tests.	2026-04-16 10:27:58 +05:45
JunghwanNA	029df375f5	fix(test): break on unknown signal in count_concat_bits When an unknown signal is encountered, total is set to -1 but the loop continues. Subsequent known signals add their widths to -1, producing incorrect totals (e.g. -1 + 16 = 15 instead of -1). This can mask genuine truncation bugs in status word packing.	2026-04-16 12:27:10 +09:00
JunghwanNA	a9ceb3c851	fix(cosim): align golden_reference ADC sign conversion with RTL The golden reference used (adc_val - 128) << 9 which subtracts 65536, but the Verilog RTL computes {1'b0,adc,9'b0} - {1'b0,8'hFF,9'b0}/2 which subtracts 0xFF00 = 65280. This creates a constant 256-LSB DC offset between the golden reference and RTL for all 256 ADC values. The bit-accurate model in fpga_model.py already uses the correct RTL formula. This aligns golden_reference.py to match. Verified: all 256 ADC input values now produce zero offset against fpga_model.py.	2026-04-16 12:27:02 +09:00
JunghwanNA	425c349184	fix(ci): use PATH-based iverilog/vvp discovery for cross-layer tests The default IVERILOG and VVP paths were hardcoded to macOS Homebrew locations (/opt/homebrew/bin/iverilog). On Ubuntu CI runners, apt installs iverilog to /usr/bin/, so the Path.exists() check returns False and all Tier 2 Verilog cosim tests are silently skipped. Change defaults to bare command names so the existing which-based fallback at line 57-58 discovers the binary via PATH on any platform.	2026-04-16 12:26:50 +09:00
Jason	b9c36dcca5	fix(ci): remove macOS test binaries from git, update .gitignore The gap3, agc, and gps test binaries (Mach-O executables compiled on macOS) were accidentally tracked. CI runs on Linux and fails with 'Exec format error'. Removed from index and added to .gitignore.	2026-04-16 00:45:52 +05:45
Jason	db4e73577e	fix: use authoritative tx frame signal for frame sync, consistent ad9523 error path FPGA-001: The previous fix derived frame boundaries from chirp_counter==0, but that counter comes from plfm_chirp_controller_enhanced which overflows to N (not wrapping at chirps_per_elev). This caused frame pulses only on 6-bit rollover (every 64 chirps) instead of every N chirps. Now wires the CDC-synchronized tx_new_chirp_frame_sync signal from the transmitter into radar_receiver_final, giving correct per-frame timing for any N. STM32-004: Changed ad9523_init() failure path from Error_Handler() to return -1, matching the pattern used by ad9523_setup() and ad9523_status() in the same function. Both halt the system, but return -1 keeps IRQs enabled for diagnostic output.	2026-04-16 00:33:27 +05:45
Jason	8187771ab0	fix: resolve 3 deferred issues (STM32-006, STM32-004, FPGA-001) STM32-006: Remove blocking do-while loop that waited for legacy GUI start flag — production V7 PyQt GUI never sends it, hanging the MCU at boot. STM32-004: Check ad9523_init() return code and call Error_Handler() on failure, matching the pattern used by all other hardware init calls. FPGA-001: Simplify frame boundary detection to only trigger on chirp_counter wrap-to-zero. Previous conditions checking == N and == 2N were unreachable dead code (counter wraps at N-1). Now correct for any chirps_per_elev value.	2026-04-16 00:13:45 +05:45
Jason	b0e5b298fe	feat(gps): add UM982 GPS driver replacing broken TinyGPS++ Implement a complete UM982 GNSS driver (um982_gps.h/.c) with: - NMEA parser for GGA, RMC, THS, VTG with multi-talker support (GP/GN/GL/GA/GB) - Correct coordinate parsing using decimal-point-based degree detection (fixes PR #68 bug: 3-digit longitude degrees) - Checksum verification on all incoming sentences - Non-blocking line assembler with ring buffer - Init sequence: UNLOG, HEADING FIXLENGTH, baseline config, NMEA enables, VERSIONA handshake (no SAVECONFIG to avoid NVM wear) - Validity/age checks with configurable timeouts Integration into main.cpp: - Replace TinyGPSPlus with UM982_GPS_t, UART5 baud 9600->115200 - Non-blocking um982_process() in main loop (single-byte UART reads) - GPS heading override with magnetometer fallback - Health check using um982_position_age() Test infrastructure: - 49 unit tests covering checksums, coordinate parsing, all sentence types, talker IDs, feed/assembly, validity, init sequence, edge cases - Mock HAL_UART_Receive with per-UART ring buffer for integration tests - All 72 MCU tests passing (23 existing + 49 new) Fixes all 12 bugs identified in PR #68 analysis (5 compile errors + 7 functional).	2026-04-15 17:46:21 +05:45