Sensor Board

vehicle-daq

Vehicle data-acquisition system: ESP32-C6 sensor nodes stream IMU and GPS over ESP-NOW to a bridge; the bridge forwards data over USB to a Raspberry Pi, which logs CSV, runs optional AHRS, and supports track capture (waypoint logging via a GPS-only “floating” node).

note: Correspondent REPLAY system is hosted here: https://github.com/Trotyl15/vehicle-replay

The two main software pieces are:

System overview

flowchart TB
  subgraph sensors["Sensor nodes"]
    SN["rev1_board<br/>IMU + GPS"]
  end

  subgraph bridge["Bridge (devkit)"]
    B["devkit_c<br/>Forward, TimeSync<br/>track heartbeats"]
  end

  subgraph host["Raspberry Pi"]
    R["rpi_rx_rust<br/>Logs, AHRS<br/>track capture"]
  end

  subgraph floating["Floating node"]
    F["sensorboard_floating<br/>GPS only"]
  end

  SN -->|"ESP-NOW (IMU, GPS, heartbeat)"| B
  B -->|"USB COBS (forwarded messages)"| R
  R -->|"TimeSync, Arm/End, RequestFloatingGps"| B
  B -->|"TrackCaptureArmed/Ended (pause TX)"| SN
  B -->|"RequestGpsCapture"| F
  F -->|"5× GPS reply"| B
  B -->|"heartbeat 0xFE (when armed)"| R

• Sensor nodes (rev1_board): Read IMU and GPS, send over ESP-NOW. When track capture is armed, they pause so the floating node’s packets aren’t dropped.
• Bridge (devkit_c): Receives ESP-NOW, assigns node IDs by MAC, forwards messages to the Pi over USB (COBS). Sends TimeSync to nodes; handles Arm/End track and RequestFloatingGps; when armed, sends a track-capture heartbeat (0xFE) to the Pi every 500 ms.
• Floating node (sensorboard_floating): GPS-only; on RequestGpsCapture it replies with the next 5 GPS samples for waypoint logging.
• Pi (rpi_rx_rust): Decodes COBS stream, writes raw CSV (and optional AHRS CSV). Can arm track capture, request floating GPS per waypoint, and write track files (~/daq/tracks/<date>/<time>.csv). Uses track heartbeats to auto-end capture if the bridge disappears; bridge auto-ends if the Pi disappears.

Raspberry Pi (rpi_rx_rust)

• Binaries: rpi_rx_rust (CLI + serial), rpi_rx_rust_gpio (GPIO-only service), rpi_rx_rust_track_test (interactive track capture), ahrs_postprocess, gps_extract.
• Default serial: /dev/ttyACM0, 115200 baud (set RPI_RX_SERIAL_PORT if the bridge is on another port).
• Logs: ~/daq/logs/<date>/ (raw and AHRS); track files: ~/daq/tracks/<date>/.
• Track capture: Arm → take location (request 5 GPS from floating node, average, append one row) → end. Heartbeat from bridge (0xFE) every 500 ms; 3 s without heartbeat or 2 s without USB from Pi triggers auto-end.

Full build and usage: sw/tools/rpi_rx_rust/README.md.

Sensor board & bridge (sensor_board_rev1_test)

• Binaries: rev1_board (sensor node), devkit_c (bridge), sensorboard_floating (GPS-only for track capture).
• Build (from sw/sensor_board/sensor_board_rev1_test/):
  • Sensor: cargo build --bin rev1_board (optional --features pos_center etc.).
  • Bridge: cargo build --bin devkit_c --no-default-features --features bridge.
  • Floating: cargo build --bin sensorboard_floating --no-default-features --features floating.
• HMI: User LED (1 Hz) + NeoPixel (state/feedback). Bridge: 4× blink when armed; orange when sending request; green/rainbow on success/timeout. Floating: green breathing when idle with fix; orange when acquiring.

Full build, features, task model, and hardware init: sw/sensor_board/sensor_board_rev1_test/README.md.

Other repos under sw/, ee/, and vision/ may have their own READMEs.