feat(gui): add FT601Connection class, USB interface selection in V65/V7

- Add FT601Connection in radar_protocol.py using ftd3xx library with
  proper setChipConfiguration re-enumeration handling (close, wait 2s,
  re-open) and 4-byte write alignment
- Add USB Interface dropdown to V65 Tk GUI (FT2232H default, FT601 option)
- Add USB Interface combo to V7 PyQt dashboard with Live/File mode toggle
- Fix mock frame_start bit 7 in both FT2232H and FT601 connections
- Use FPGA range data from USB packets instead of recomputing in Python
- Export FT601Connection from v7/hardware.py and v7/__init__.py
- Add 7 FT601Connection tests (91 total in test_GUI_V65_Tk.py)

9_Firmware/9_3_GUI/GUI_V65_Tk.py

@@ -59,7 +59,7 @@ except (ModuleNotFoundError, ImportError):
 
 # Import protocol layer (no GUI deps)
 from radar_protocol import (
-    RadarProtocol, FT2232HConnection,
+    RadarProtocol, FT2232HConnection, FT601Connection,
     DataRecorder, RadarAcquisition,
     RadarFrame, StatusResponse,
     NUM_RANGE_BINS, NUM_DOPPLER_BINS, WATERFALL_DEPTH,
@@ -388,10 +388,11 @@ class RadarDashboard:
     BANDWIDTH = 500e6        # Hz — chirp bandwidth
     C = 3e8                  # m/s — speed of light
 
-    def __init__(self, root: tk.Tk, connection: FT2232HConnection,
+    def __init__(self, root: tk.Tk, mock: bool,
                  recorder: DataRecorder, device_index: int = 0):
         self.root = root
-        self.conn = connection
+        self._mock = mock
+        self.conn: FT2232HConnection | FT601Connection | None = None
         self.recorder = recorder
         self.device_index = device_index
 
@@ -485,6 +486,16 @@ class RadarDashboard:
                                        style="Accent.TButton")
         self.btn_connect.pack(side="right", padx=4)
 
+        # USB Interface selector (production FT2232H / premium FT601)
+        self._usb_iface_var = tk.StringVar(value="FT2232H (Production)")
+        self.cmb_usb_iface = ttk.Combobox(
+            top, textvariable=self._usb_iface_var,
+            values=["FT2232H (Production)", "FT601 (Premium)"],
+            state="readonly", width=20,
+        )
+        self.cmb_usb_iface.pack(side="right", padx=4)
+        ttk.Label(top, text="USB:", font=("Menlo", 10)).pack(side="right")
+
         self.btn_record = ttk.Button(top, text="Record", command=self._on_record)
         self.btn_record.pack(side="right", padx=4)
 
@@ -1018,15 +1029,17 @@ class RadarDashboard:
 
     # ------------------------------------------------------------ Actions
     def _on_connect(self):
-        if self.conn.is_open:
+        if self.conn is not None and self.conn.is_open:
             # Disconnect
             if self._acq_thread is not None:
                 self._acq_thread.stop()
                 self._acq_thread.join(timeout=2)
                 self._acq_thread = None
             self.conn.close()
+            self.conn = None
             self.lbl_status.config(text="DISCONNECTED", foreground=RED)
             self.btn_connect.config(text="Connect")
+            self.cmb_usb_iface.config(state="readonly")
             log.info("Disconnected")
             return
 
@@ -1036,6 +1049,16 @@ class RadarDashboard:
         if self._replay_active:
             self._replay_stop()
 
+        # Create connection based on USB Interface selector
+        iface = self._usb_iface_var.get()
+        if "FT601" in iface:
+            self.conn = FT601Connection(mock=self._mock)
+        else:
+            self.conn = FT2232HConnection(mock=self._mock)
+
+        # Disable interface selector while connecting/connected
+        self.cmb_usb_iface.config(state="disabled")
+
         # Open connection in a background thread to avoid blocking the GUI
         self.lbl_status.config(text="CONNECTING...", foreground=YELLOW)
         self.btn_connect.config(state="disabled")
@@ -1062,6 +1085,8 @@ class RadarDashboard:
         else:
             self.lbl_status.config(text="CONNECT FAILED", foreground=RED)
             self.btn_connect.config(text="Connect")
+            self.cmb_usb_iface.config(state="readonly")
+            self.conn = None
 
     def _on_record(self):
         if self.recorder.recording:
@@ -1110,6 +1135,9 @@ class RadarDashboard:
                  f"Opcode 0x{opcode:02X} is hardware-only (ignored in replay)"))
             return
         cmd = RadarProtocol.build_command(opcode, value)
+        if self.conn is None:
+            log.warning("No connection — command not sent")
+            return
         ok = self.conn.write(cmd)
         log.info(f"CMD 0x{opcode:02X} val={value} ({'OK' if ok else 'FAIL'})")
 
@@ -1148,7 +1176,7 @@ class RadarDashboard:
         if self._replay_active or self._replay_ctrl is not None:
             self._replay_stop()
         if self._acq_thread is not None:
-            if self.conn.is_open:
+            if self.conn is not None and self.conn.is_open:
                 self._on_connect()  # disconnect
             else:
                 # Connection dropped unexpectedly — just clean up the thread
@@ -1547,17 +1575,17 @@ def main():
     args = parser.parse_args()
 
     if args.live:
-        conn = FT2232HConnection(mock=False)
+        mock = False
         mode_str = "LIVE"
     else:
-        conn = FT2232HConnection(mock=True)
+        mock = True
         mode_str = "MOCK"
 
     recorder = DataRecorder()
 
     root = tk.Tk()
 
-    dashboard = RadarDashboard(root, conn, recorder, device_index=args.device)
+    dashboard = RadarDashboard(root, mock, recorder, device_index=args.device)
 
     if args.record:
         filepath = os.path.join(
@@ -1582,8 +1610,8 @@ def main():
         if dashboard._acq_thread is not None:
             dashboard._acq_thread.stop()
             dashboard._acq_thread.join(timeout=2)
-        if conn.is_open:
+        if dashboard.conn is not None and dashboard.conn.is_open:
-            conn.close()
+            dashboard.conn.close()
         if recorder.recording:
             recorder.stop()
         root.destroy()

9_Firmware/9_3_GUI/radar_protocol.py

@@ -6,6 +6,7 @@ Pure-logic module for USB packet parsing and command building.
 No GUI dependencies — safe to import from tests and headless scripts.
 
 USB Interface: FT2232H USB 2.0 (8-bit, 50T production board) via pyftdi
+               FT601 USB 3.0 (32-bit, 200T premium board) via ftd3xx
 
 USB Packet Protocol (11-byte):
   TX (FPGA→Host):
@@ -22,7 +23,7 @@ import queue
 import logging
 import contextlib
 from dataclasses import dataclass, field
-from typing import Any
+from typing import Any, ClassVar
 from enum import IntEnum
 
 
@@ -200,7 +201,9 @@ class RadarProtocol:
         range_i = _to_signed16(struct.unpack_from(">H", raw, 3)[0])
         doppler_i = _to_signed16(struct.unpack_from(">H", raw, 5)[0])
         doppler_q = _to_signed16(struct.unpack_from(">H", raw, 7)[0])
-        detection = raw[9] & 0x01
+        det_byte = raw[9]
+        detection = det_byte & 0x01
+        frame_start = (det_byte >> 7) & 0x01
 
         return {
             "range_i": range_i,
@@ -208,6 +211,7 @@ class RadarProtocol:
             "doppler_i": doppler_i,
             "doppler_q": doppler_q,
             "detection": detection,
+            "frame_start": frame_start,
         }
 
     @staticmethod
@@ -433,7 +437,191 @@ class FT2232HConnection:
             pkt += struct.pack(">h", np.clip(range_i, -32768, 32767))
             pkt += struct.pack(">h", np.clip(dop_i, -32768, 32767))
             pkt += struct.pack(">h", np.clip(dop_q, -32768, 32767))
-            pkt.append(detection & 0x01)
+            # Bit 7 = frame_start (sample_counter == 0), bit 0 = detection
+            det_byte = (detection & 0x01) | (0x80 if idx == 0 else 0x00)
+            pkt.append(det_byte)
+            pkt.append(FOOTER_BYTE)
+
+            buf += pkt
+
+        self._mock_seq_idx = (start_idx + num_packets) % NUM_CELLS
+        return bytes(buf)
+
+
+# ============================================================================
+# FT601 USB 3.0 Connection (premium board only)
+# ============================================================================
+
+# Optional ftd3xx import (FTDI's proprietary driver for FT60x USB 3.0 chips).
+# pyftdi does NOT support FT601 — it only handles USB 2.0 chips (FT232H, etc.)
+try:
+    import ftd3xx  # type: ignore[import-untyped]
+    FTD3XX_AVAILABLE = True
+    _Ftd3xxError: type = ftd3xx.FTD3XXError  # type: ignore[attr-defined]
+except ImportError:
+    FTD3XX_AVAILABLE = False
+    _Ftd3xxError = OSError  # fallback for type-checking; never raised
+
+
+class FT601Connection:
+    """
+    FT601 USB 3.0 SuperSpeed FIFO bridge — premium board only.
+
+    The FT601 has a 32-bit data bus and runs at 100 MHz.
+    VID:PID = 0x0403:0x6030 or 0x6031 (FTDI FT60x).
+
+    Requires the ``ftd3xx`` library (``pip install ftd3xx`` on Windows,
+    or ``libft60x`` on Linux). This is FTDI's proprietary USB 3.0 driver;
+    ``pyftdi`` only supports USB 2.0 and will NOT work with FT601.
+
+    Public contract matches FT2232HConnection so callers can swap freely.
+    """
+
+    VID = 0x0403
+    PID_LIST: ClassVar[list[int]] = [0x6030, 0x6031]
+
+    def __init__(self, mock: bool = True):
+        self._mock = mock
+        self._dev = None
+        self._lock = threading.Lock()
+        self.is_open = False
+        # Mock state (reuses same synthetic data pattern)
+        self._mock_frame_num = 0
+        self._mock_rng = np.random.RandomState(42)
+
+    def open(self, device_index: int = 0) -> bool:
+        if self._mock:
+            self.is_open = True
+            log.info("FT601 mock device opened (no hardware)")
+            return True
+
+        if not FTD3XX_AVAILABLE:
+            log.error(
+                "ftd3xx library required for FT601 hardware — "
+                "install with: pip install ftd3xx"
+            )
+            return False
+
+        try:
+            self._dev = ftd3xx.create(device_index, ftd3xx.OPEN_BY_INDEX)
+            if self._dev is None:
+                log.error("No FT601 device found at index %d", device_index)
+                return False
+            # Verify chip configuration — only reconfigure if needed.
+            # setChipConfiguration triggers USB re-enumeration, which
+            # invalidates the device handle and requires a re-open cycle.
+            cfg = self._dev.getChipConfiguration()
+            needs_reconfig = (
+                cfg.FIFOMode != 0            # 245 FIFO mode
+                or cfg.ChannelConfig != 0    # 1 channel, 32-bit
+                or cfg.OptionalFeatureSupport != 0
+            )
+            if needs_reconfig:
+                cfg.FIFOMode = 0
+                cfg.ChannelConfig = 0
+                cfg.OptionalFeatureSupport = 0
+                self._dev.setChipConfiguration(cfg)
+                # Device re-enumerates — close stale handle, wait, re-open
+                self._dev.close()
+                self._dev = None
+                import time
+                time.sleep(2.0)  # wait for USB re-enumeration
+                self._dev = ftd3xx.create(device_index, ftd3xx.OPEN_BY_INDEX)
+                if self._dev is None:
+                    log.error("FT601 not found after reconfiguration")
+                    return False
+                log.info("FT601 reconfigured and re-opened (index %d)", device_index)
+            self.is_open = True
+            log.info("FT601 device opened (index %d)", device_index)
+            return True
+        except (OSError, _Ftd3xxError) as e:
+            log.error("FT601 open failed: %s", e)
+            self._dev = None
+            return False
+
+    def close(self):
+        if self._dev is not None:
+            with contextlib.suppress(Exception):
+                self._dev.close()
+            self._dev = None
+        self.is_open = False
+
+    def read(self, size: int = 4096) -> bytes | None:
+        """Read raw bytes from FT601. Returns None on error/timeout."""
+        if not self.is_open:
+            return None
+
+        if self._mock:
+            return self._mock_read(size)
+
+        with self._lock:
+            try:
+                data = self._dev.readPipe(0x82, size, raw=True)
+                return bytes(data) if data else None
+            except (OSError, _Ftd3xxError) as e:
+                log.error("FT601 read error: %s", e)
+                return None
+
+    def write(self, data: bytes) -> bool:
+        """Write raw bytes to FT601. Data must be 4-byte aligned for 32-bit bus."""
+        if not self.is_open:
+            return False
+
+        if self._mock:
+            log.info(f"FT601 mock write: {data.hex()}")
+            return True
+
+        # Pad to 4-byte alignment (FT601 32-bit bus requirement).
+        # NOTE: Radar commands are already 4 bytes, so this should be a no-op.
+        remainder = len(data) % 4
+        if remainder:
+            data = data + b"\x00" * (4 - remainder)
+
+        with self._lock:
+            try:
+                written = self._dev.writePipe(0x02, data, raw=True)
+                return written == len(data)
+            except (OSError, _Ftd3xxError) as e:
+                log.error("FT601 write error: %s", e)
+                return False
+
+    def _mock_read(self, size: int) -> bytes:
+        """Generate synthetic radar packets (same pattern as FT2232H mock)."""
+        time.sleep(0.05)
+        self._mock_frame_num += 1
+
+        buf = bytearray()
+        num_packets = min(NUM_CELLS, size // DATA_PACKET_SIZE)
+        start_idx = getattr(self, "_mock_seq_idx", 0)
+
+        for n in range(num_packets):
+            idx = (start_idx + n) % NUM_CELLS
+            rbin = idx // NUM_DOPPLER_BINS
+            dbin = idx % NUM_DOPPLER_BINS
+
+            range_i = int(self._mock_rng.normal(0, 100))
+            range_q = int(self._mock_rng.normal(0, 100))
+            if abs(rbin - 20) < 3:
+                range_i += 5000
+                range_q += 3000
+
+            dop_i = int(self._mock_rng.normal(0, 50))
+            dop_q = int(self._mock_rng.normal(0, 50))
+            if abs(rbin - 20) < 3 and abs(dbin - 8) < 2:
+                dop_i += 8000
+                dop_q += 4000
+
+            detection = 1 if (abs(rbin - 20) < 2 and abs(dbin - 8) < 2) else 0
+
+            pkt = bytearray()
+            pkt.append(HEADER_BYTE)
+            pkt += struct.pack(">h", np.clip(range_q, -32768, 32767))
+            pkt += struct.pack(">h", np.clip(range_i, -32768, 32767))
+            pkt += struct.pack(">h", np.clip(dop_i, -32768, 32767))
+            pkt += struct.pack(">h", np.clip(dop_q, -32768, 32767))
+            # Bit 7 = frame_start (sample_counter == 0), bit 0 = detection
+            det_byte = (detection & 0x01) | (0x80 if idx == 0 else 0x00)
+            pkt.append(det_byte)
             pkt.append(FOOTER_BYTE)
 
             buf += pkt
@@ -600,6 +788,12 @@ class RadarAcquisition(threading.Thread):
             if sample.get("detection", 0):
                 self._frame.detections[rbin, dbin] = 1
                 self._frame.detection_count += 1
+            # Accumulate FPGA range profile data (matched-filter output)
+            # Each sample carries the range_i/range_q for this range bin.
+            # Accumulate magnitude across Doppler bins for the range profile.
+            ri = int(sample.get("range_i", 0))
+            rq = int(sample.get("range_q", 0))
+            self._frame.range_profile[rbin] += abs(ri) + abs(rq)
 
         self._sample_idx += 1
 
@@ -607,11 +801,11 @@ class RadarAcquisition(threading.Thread):
             self._finalize_frame()
 
     def _finalize_frame(self):
-        """Complete frame: compute range profile, push to queue, record."""
+        """Complete frame: push to queue, record."""
         self._frame.timestamp = time.time()
         self._frame.frame_number = self._frame_num
-        # Range profile = sum of magnitude across Doppler bins
+        # range_profile is already accumulated from FPGA range_i/range_q
-        self._frame.range_profile = np.sum(self._frame.magnitude, axis=1)
+        # data in _ingest_sample(). No need to synthesize from doppler magnitude.
 
         # Push to display queue (drop old if backed up)
         try:

9_Firmware/9_3_GUI/test_GUI_V65_Tk.py

@@ -16,7 +16,7 @@ import unittest
 import numpy as np
 
 from radar_protocol import (
-    RadarProtocol, FT2232HConnection, DataRecorder, RadarAcquisition,
+    RadarProtocol, FT2232HConnection, FT601Connection, DataRecorder, RadarAcquisition,
     RadarFrame, StatusResponse, Opcode,
     HEADER_BYTE, FOOTER_BYTE, STATUS_HEADER_BYTE,
     NUM_RANGE_BINS, NUM_DOPPLER_BINS,
@@ -312,6 +312,61 @@ class TestFT2232HConnection(unittest.TestCase):
         self.assertFalse(conn.write(b"\x00\x00\x00\x00"))
 
 
+class TestFT601Connection(unittest.TestCase):
+    """Test mock FT601 connection (mirrors FT2232H tests)."""
+
+    def test_mock_open_close(self):
+        conn = FT601Connection(mock=True)
+        self.assertTrue(conn.open())
+        self.assertTrue(conn.is_open)
+        conn.close()
+        self.assertFalse(conn.is_open)
+
+    def test_mock_read_returns_data(self):
+        conn = FT601Connection(mock=True)
+        conn.open()
+        data = conn.read(4096)
+        self.assertIsNotNone(data)
+        self.assertGreater(len(data), 0)
+        conn.close()
+
+    def test_mock_read_contains_valid_packets(self):
+        """Mock data should contain parseable data packets."""
+        conn = FT601Connection(mock=True)
+        conn.open()
+        raw = conn.read(4096)
+        packets = RadarProtocol.find_packet_boundaries(raw)
+        self.assertGreater(len(packets), 0)
+        for start, end, ptype in packets:
+            if ptype == "data":
+                result = RadarProtocol.parse_data_packet(raw[start:end])
+                self.assertIsNotNone(result)
+        conn.close()
+
+    def test_mock_write(self):
+        conn = FT601Connection(mock=True)
+        conn.open()
+        cmd = RadarProtocol.build_command(0x01, 1)
+        self.assertTrue(conn.write(cmd))
+        conn.close()
+
+    def test_write_pads_to_4_bytes(self):
+        """FT601 write() should pad data to 4-byte alignment."""
+        conn = FT601Connection(mock=True)
+        conn.open()
+        # 3-byte payload should be padded internally (no error)
+        self.assertTrue(conn.write(b"\x01\x02\x03"))
+        conn.close()
+
+    def test_read_when_closed(self):
+        conn = FT601Connection(mock=True)
+        self.assertIsNone(conn.read())
+
+    def test_write_when_closed(self):
+        conn = FT601Connection(mock=True)
+        self.assertFalse(conn.write(b"\x00\x00\x00\x00"))
+
+
 class TestDataRecorder(unittest.TestCase):
     """Test HDF5 recording (skipped if h5py not available)."""
 

9_Firmware/9_3_GUI/v7/__init__.py

@@ -26,6 +26,7 @@ from .models import (
 # Hardware interfaces — production protocol via radar_protocol.py
 from .hardware import (
     FT2232HConnection,
+    FT601Connection,
     RadarProtocol,
     Opcode,
     RadarAcquisition,
@@ -89,7 +90,7 @@ __all__ = [  # noqa: RUF022
     "USB_AVAILABLE", "FTDI_AVAILABLE", "SCIPY_AVAILABLE",
     "SKLEARN_AVAILABLE", "FILTERPY_AVAILABLE",
     # hardware — production FPGA protocol
-    "FT2232HConnection", "RadarProtocol", "Opcode",
+    "FT2232HConnection", "FT601Connection", "RadarProtocol", "Opcode",
     "RadarAcquisition", "RadarFrame", "StatusResponse", "DataRecorder",
     "STM32USBInterface",
     # processing

9_Firmware/9_3_GUI/v7/dashboard.py

@@ -13,13 +13,14 @@ RadarDashboard is a QMainWindow with six tabs:
   6. Settings    — Host-side DSP parameters + About section
 
 Uses production radar_protocol.py for all FPGA communication:
-  - FT2232HConnection for real hardware
+  - FT2232HConnection for production board (FT2232H USB 2.0)
+  - FT601Connection for premium board (FT601 USB 3.0) — selectable from GUI
   - Unified replay via SoftwareFPGA + ReplayEngine + ReplayWorker
   - Mock mode (FT2232HConnection(mock=True)) for development
 
 The old STM32 magic-packet start flow has been removed. FPGA registers
 are controlled directly via 4-byte {opcode, addr, value_hi, value_lo}
-commands sent over FT2232H.
+commands sent over FT2232H or FT601.
 """
 
 from __future__ import annotations
@@ -55,6 +56,7 @@ from .models import (
 )
 from .hardware import (
     FT2232HConnection,
+    FT601Connection,
     RadarProtocol,
     RadarFrame,
     StatusResponse,
@@ -142,7 +144,7 @@ class RadarDashboard(QMainWindow):
         )
 
         # Hardware interfaces — production protocol
-        self._connection: FT2232HConnection | None = None
+        self._connection: FT2232HConnection | FT601Connection | None = None
         self._stm32 = STM32USBInterface()
         self._recorder = DataRecorder()
 
@@ -364,7 +366,7 @@ class RadarDashboard(QMainWindow):
         # Row 0: connection mode + device combos + buttons
         ctrl_layout.addWidget(QLabel("Mode:"), 0, 0)
         self._mode_combo = QComboBox()
-        self._mode_combo.addItems(["Mock", "Live FT2232H", "Replay"])
+        self._mode_combo.addItems(["Mock", "Live", "Replay"])
         self._mode_combo.setCurrentIndex(0)
         ctrl_layout.addWidget(self._mode_combo, 0, 1)
 
@@ -377,6 +379,13 @@ class RadarDashboard(QMainWindow):
         refresh_btn.clicked.connect(self._refresh_devices)
         ctrl_layout.addWidget(refresh_btn, 0, 4)
 
+        # USB Interface selector (production FT2232H / premium FT601)
+        ctrl_layout.addWidget(QLabel("USB Interface:"), 0, 5)
+        self._usb_iface_combo = QComboBox()
+        self._usb_iface_combo.addItems(["FT2232H (Production)", "FT601 (Premium)"])
+        self._usb_iface_combo.setCurrentIndex(0)
+        ctrl_layout.addWidget(self._usb_iface_combo, 0, 6)
+
         self._start_btn = QPushButton("Start Radar")
         self._start_btn.setStyleSheet(
             f"QPushButton {{ background-color: {DARK_SUCCESS}; color: white; font-weight: bold; }}"
@@ -1001,7 +1010,8 @@ class RadarDashboard(QMainWindow):
         self._conn_ft2232h = self._make_status_label("FT2232H")
         self._conn_stm32 = self._make_status_label("STM32 USB")
 
-        conn_layout.addWidget(QLabel("FT2232H:"), 0, 0)
+        self._conn_usb_label = QLabel("USB Data:")
+        conn_layout.addWidget(self._conn_usb_label, 0, 0)
         conn_layout.addWidget(self._conn_ft2232h, 0, 1)
         conn_layout.addWidget(QLabel("STM32 USB:"), 1, 0)
         conn_layout.addWidget(self._conn_stm32, 1, 1)
@@ -1167,7 +1177,7 @@ class RadarDashboard(QMainWindow):
         about_lbl = QLabel(
             "<b>AERIS-10 Radar System V7</b><br>"
             "PyQt6 Edition with Embedded Leaflet Map<br><br>"
-            "<b>Data Interface:</b> FT2232H USB 2.0 (production protocol)<br>"
+            "<b>Data Interface:</b> FT2232H USB 2.0 (production) / FT601 USB 3.0 (premium)<br>"
             "<b>FPGA Protocol:</b> 4-byte register commands, 0xAA/0xBB packets<br>"
             "<b>Map:</b> OpenStreetMap + Leaflet.js<br>"
             "<b>Framework:</b> PyQt6 + QWebEngine<br>"
@@ -1224,7 +1234,7 @@ class RadarDashboard(QMainWindow):
     # =====================================================================
 
     def _send_fpga_cmd(self, opcode: int, value: int):
-        """Send a 4-byte register command to the FPGA via FT2232H."""
+        """Send a 4-byte register command to the FPGA via USB (FT2232H or FT601)."""
         if self._connection is None or not self._connection.is_open:
             logger.warning(f"Cannot send 0x{opcode:02X}={value}: no connection")
             return
@@ -1287,16 +1297,26 @@ class RadarDashboard(QMainWindow):
 
             if "Mock" in mode:
                 self._replay_mode = False
-                self._connection = FT2232HConnection(mock=True)
+                iface = self._usb_iface_combo.currentText()
+                if "FT601" in iface:
+                    self._connection = FT601Connection(mock=True)
+                else:
+                    self._connection = FT2232HConnection(mock=True)
                 if not self._connection.open():
                     QMessageBox.critical(self, "Error", "Failed to open mock connection.")
                     return
             elif "Live" in mode:
                 self._replay_mode = False
-                self._connection = FT2232HConnection(mock=False)
+                iface = self._usb_iface_combo.currentText()
+                if "FT601" in iface:
+                    self._connection = FT601Connection(mock=False)
+                    iface_name = "FT601"
+                else:
+                    self._connection = FT2232HConnection(mock=False)
+                    iface_name = "FT2232H"
                 if not self._connection.open():
                     QMessageBox.critical(self, "Error",
-                                         "Failed to open FT2232H. Check USB connection.")
+                                         f"Failed to open {iface_name}. Check USB connection.")
                     return
             elif "Replay" in mode:
                 self._replay_mode = True
@@ -1368,6 +1388,7 @@ class RadarDashboard(QMainWindow):
                 self._start_btn.setEnabled(False)
                 self._stop_btn.setEnabled(True)
                 self._mode_combo.setEnabled(False)
+                self._usb_iface_combo.setEnabled(False)
                 self._demo_btn_main.setEnabled(False)
                 self._demo_btn_map.setEnabled(False)
                 n_frames = self._replay_engine.total_frames
@@ -1417,6 +1438,7 @@ class RadarDashboard(QMainWindow):
             self._start_btn.setEnabled(False)
             self._stop_btn.setEnabled(True)
             self._mode_combo.setEnabled(False)
+            self._usb_iface_combo.setEnabled(False)
             self._demo_btn_main.setEnabled(False)
             self._demo_btn_map.setEnabled(False)
             self._status_label_main.setText(f"Status: Running ({mode})")
@@ -1462,6 +1484,7 @@ class RadarDashboard(QMainWindow):
         self._start_btn.setEnabled(True)
         self._stop_btn.setEnabled(False)
         self._mode_combo.setEnabled(True)
+        self._usb_iface_combo.setEnabled(True)
         self._demo_btn_main.setEnabled(True)
         self._demo_btn_map.setEnabled(True)
         self._status_label_main.setText("Status: Radar stopped")
@@ -1954,6 +1977,12 @@ class RadarDashboard(QMainWindow):
         self._set_conn_indicator(self._conn_ft2232h, conn_open)
         self._set_conn_indicator(self._conn_stm32, self._stm32.is_open)
 
+        # Update USB label to reflect which interface is active
+        if isinstance(self._connection, FT601Connection):
+            self._conn_usb_label.setText("FT601:")
+        else:
+            self._conn_usb_label.setText("FT2232H:")
+
         gps_count = self._gps_packet_count
         if self._gps_worker:
             gps_count = self._gps_worker.gps_count

9_Firmware/9_3_GUI/v7/hardware.py

@@ -25,6 +25,7 @@ if USB_AVAILABLE:
 sys.path.insert(0, os.path.join(os.path.dirname(__file__), ".."))
 from radar_protocol import (  # noqa: F401 — re-exported for v7 package
     FT2232HConnection,
+    FT601Connection,
     RadarProtocol,
     Opcode,
     RadarAcquisition,