Add GPS integrity checks and GPS IMU ESKF fusion tools

soc/software/fusion/serial_capture.py

@@ -0,0 +1,73 @@
+#!/usr/bin/env python3
+"""Capture a line-oriented bare-metal UART stream with host timestamps."""
+
+from __future__ import annotations
+
+import argparse
+import csv
+import time
+from pathlib import Path
+
+import serial
+
+
+def parse_args() -> argparse.Namespace:
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--port", default="/dev/ttyUSB2")
+    parser.add_argument("--baud", type=int, default=115200)
+    parser.add_argument("--duration", type=float, default=60.0)
+    parser.add_argument("--output", type=Path, required=True)
+    parser.add_argument(
+        "--stop-text",
+        help="stop early after a line containing this text (duration remains a limit)",
+    )
+    return parser.parse_args()
+
+
+def main() -> int:
+    args = parse_args()
+    args.output.parent.mkdir(parents=True, exist_ok=True)
+
+    line_count = 0
+    byte_count = 0
+    start_wall_ns = time.time_ns()
+    start_mono_ns = time.monotonic_ns()
+    deadline_ns = start_mono_ns + int(args.duration * 1e9)
+
+    with serial.Serial(args.port, args.baud, timeout=0.1) as uart, args.output.open(
+        "w", newline="", encoding="utf-8"
+    ) as stream:
+        writer = csv.writer(stream)
+        writer.writerow(["host_monotonic_s", "host_unix_s", "uart_line"])
+        uart.reset_input_buffer()
+
+        while time.monotonic_ns() < deadline_ns:
+            raw = uart.readline()
+            if not raw:
+                continue
+            now_mono_ns = time.monotonic_ns()
+            now_wall_ns = time.time_ns()
+            byte_count += len(raw)
+            line = raw.decode("utf-8", errors="replace").rstrip("\r\n")
+            writer.writerow(
+                [
+                    f"{(now_mono_ns - start_mono_ns) / 1e9:.9f}",
+                    f"{now_wall_ns / 1e9:.9f}",
+                    line,
+                ]
+            )
+            line_count += 1
+            if args.stop_text and args.stop_text in line:
+                break
+
+    elapsed_s = (time.monotonic_ns() - start_mono_ns) / 1e9
+    print(
+        f"captured lines={line_count} bytes={byte_count} "
+        f"elapsed={elapsed_s:.3f}s output={args.output} "
+        f"start_unix={start_wall_ns / 1e9:.6f}"
+    )
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())