ecu-tests/docs/09_raspberry_pi_deployment.md

Raspberry Pi Deployment Guide

This guide explains how to run the ECU testing framework on a Raspberry Pi (Debian/Raspberry Pi OS). It covers environment setup, hardware integration via MUM (recommended) or the deprecated BabyLin (legacy rigs only), running tests headless, and installing as a systemd service.

Note: The MUM (Melexis Universal Master) is networked, so the Pi only needs IP reachability to the MUM (default 192.168.7.2) — there are no Pi-side native libs to worry about. BabyLin (deprecated) needs ARM Linux native libraries; if those aren't available, use Mock or MUM on the Pi instead. New deployments should not target BabyLin.

1) Choose your interface

• MUM (recommended for hardware on Pi): interface.type: mum. Requires Melexis pylin + pymumclient (see vendor/automated_lin_test/install_packages.sh) and IP reachability to the MUM device.
• Mock (recommended for headless/dev on Pi): interface.type: mock
• BabyLIN (DEPRECATED — only for legacy rigs and only if ARM/Linux support is available): interface.type: babylin and ensure the SDK's BabyLIN_library.py and corresponding Linux/ARM shared libraries are available under vendor/ or on PYTHONPATH/LD_LIBRARY_PATH. Selecting this path emits a DeprecationWarning.

2) Install prerequisites

sudo apt update
sudo apt install -y python3 python3-venv python3-pip git

Optional (for the deprecated BabyLin path or USB tools):

sudo apt install -y libusb-1.0-0 udev

3) Clone and set up

# clone your repo
git clone <your-repo-url> ~/ecu_tests
cd ~/ecu_tests

# create venv
python3 -m venv .venv
source .venv/bin/activate

# install deps
pip install -r requirements.txt

4) Configure

Create or edit config/test_config.yaml:

interface:
  type: mock   # or "mum" for hardware (current); "babylin" is deprecated
  channel: 1
  bitrate: 19200
flash:
  enabled: false

Optionally point to another config file via env var:

export ECU_TESTS_CONFIG=$(pwd)/config/test_config.yaml

If using the MUM on the Pi, set:

interface:
  type: mum
  host: 192.168.7.2          # adjust to your MUM IP
  lin_device: lin0
  power_device: power_out0
  bitrate: 19200
  boot_settle_seconds: 0.5
  frame_lengths:
    0x0A: 8
    0x11: 4

Confirm reachability before running tests:

ping -c 2 192.168.7.2

If using BabyLIN on Linux/ARM with the SDK wrapper (DEPRECATED, legacy rigs only), set:

interface:
  type: babylin            # deprecated; prefer "mum"
  channel: 0
  sdf_path: "/home/pi/ecu_tests/vendor/Example.sdf"
  schedule_nr: 0

5) Run tests on Pi

source .venv/bin/activate
python -m pytest -m "not hardware" -v

Artifacts are in reports/ (HTML, JUnit, JSON, summary MD).

6) Run as a systemd service (headless)

This section lets the Pi run the test suite on boot or on demand.

Create a runner script

Create scripts/run_tests.sh:

#!/usr/bin/env bash
set -euo pipefail
cd "$(dirname "$0")/.."
source .venv/bin/activate
# optionally set custom config
# export ECU_TESTS_CONFIG=$(pwd)/config/test_config.yaml
python -m pytest -v

Make it executable:

chmod +x scripts/run_tests.sh

Create a systemd unit

Create scripts/ecu-tests.service:

[Unit]
Description=ECU Tests Runner
After=network-online.target
Wants=network-online.target

[Service]
Type=oneshot
WorkingDirectory=/home/pi/ecu_tests
ExecStart=/home/pi/ecu_tests/scripts/run_tests.sh
User=pi
Group=pi
Environment=ECU_TESTS_CONFIG=/home/pi/ecu_tests/config/test_config.yaml
# Capture output to a log file
StandardOutput=append:/home/pi/ecu_tests/reports/service.log
StandardError=append:/home/pi/ecu_tests/reports/service.err

[Install]
WantedBy=multi-user.target

Install and run:

sudo mkdir -p /home/pi/ecu_tests/reports
sudo cp scripts/ecu-tests.service /etc/systemd/system/ecu-tests.service
sudo systemctl daemon-reload
sudo systemctl enable ecu-tests.service
# Start manually
sudo systemctl start ecu-tests.service
# Check status
systemctl status ecu-tests.service

7) USB and permissions (if using hardware)

• Create udev rules for your device (if required by vendor)
• Add user to dialout or plugdev groups if serial/USB access is needed
• Confirm your hardware library is found by Python and the dynamic linker:
  • For the deprecated BabyLIN path only: ensure vendor/BabyLIN_library.py is importable (add vendor/ to PYTHONPATH if needed)
  • Ensure .so files are discoverable (e.g., place in /usr/local/lib and run sudo ldconfig, or set LD_LIBRARY_PATH)

8) Tips

• Use the mock interface on Pi for quick smoke tests and documentation/report generation
• For full HIL on Pi, the MUM is the easiest path — it's IP-reachable so the Pi doesn't need vendor-specific native libraries, just the Melexis Python packages (pylin, pymumclient)
• For the deprecated BabyLIN HIL path, ensure vendor SDK supports Linux/ARM and provide a shared object (.so) and headers — but prefer migrating these rigs to MUM
• If only Windows is supported by your hardware path, run the hardware suite on a Windows host and use the Pi for lightweight tasks (archiving, reporting, quick checks)