A Raspberry Pi Pico-based FlexRay man-in-the-middle (MITM) bridge that forwards frames between ECU and vehicle transceivers, with a Panda-compatible USB interface.

• Core features:
  • Continuous, bidirectional FlexRay frame forwarding (vehicle ↔ ECU)
  • USB interface is Panda-compatible
  • Man-in-the-middle bridge mode for FlexRay capture, forwarding, and injection workflows

1. For read-only FlexRay frame capture, connect a single transceiver to the vehicle’s bus, attach its BP/BM lines to the FlexRay lines in your vehicle.
2. To differentiate frames from the ECU and the vehicle, use a man-in-the-middle (MITM) setup: split the original FlexRay cable and connect each half to its own transceiver with separate BP/BM pairs—one transceiver for the ECU side, one for the vehicle side.

FR1/FR2 are the primary MITM pair. FR3/FR4 are an optional second pair; leaving FR3/FR4 unconnected does not affect normal FR1/FR2 operation.

Refer to your board’s pinout for physical pad/header locations. Signals below use Pico GPIO numbers as configured in src/main.c.

Note:
You can use any FlexRay transceiver you have available. The following transceivers are pin-to-pin compatible and can be used interchangeably:

• TLE9222
• TJA1082
• NCV7383

git clone https://github.com/dynm/pico-flexray/
cd pico-flexray

Option 1: Visual Studio Code

1. Install the Raspberry Pi Pico extension
2. Open this repo, do not enable RISC-V instructions
3. Click the Pico extension tab on the left panel
4. Click "Switch Board" and select your Pico board
5. Hold BOOT, plug USB, then you can release BOOT
6. Click "Run Project (USB)"
7. Done!

Option 2: Command line Prerequisites:

• Raspberry Pi Pico SDK 2.1.x (env var PICO_SDK_PATH or the VS Code Pico extension auto-setup)
• picotool for flashing, or UF2 drag-and-drop

Configure and build (default board is set in CMakeLists.txt to pico2):

cd pico-flexray
mkdir build && cd build
ninja -C build

Artifacts are produced in build/ (e.g., pico_flexray.uf2, pico_flexray.elf).

Flash to device:

• UF2: Hold BOOT, plug USB, then copy build/pico_flexray.uf2 to the RPI-RP2 mass storage device.
• Picotool: put the board in BOOTSEL or use reset-to-boot, then:

picotool load -f build/pico_flexray.uf2

Run-time:

• USB enumerates as a vendor-specific device (no CDC serial). Use UART for logs.
• On boot, the app prints pin assignments and status, enables transceivers, and starts forwarding.

If you use a different board or wiring, update the GPIO defines at the top of src/main.c and/or modify set(PICO_BOARD pico2 CACHE STRING "Board type") in CMakeLists.txt. Rebuild and reflash.

To visualize FlexRay data using Cabana:

1. Clone the OpenPilot repository and switch to the FlexRay-enabled branch:

   git clone https://github.com/dynm/openpilot
   cd openpilot
   git checkout cabana-flexray

2. Set up the environment:

   ./tools/op.sh setup

3. Build Cabana:

   source .venv/bin/activate
   scons -j$(nproc) tools/cabana/cabana

4. Launch Cabana:

   ./tools/cabana/cabana