sl-firmware
381549b33f
Critical safety system with <50ms latency emergency response. ROS2 action server /saltybot/estop with unified trigger sources: - Voice commands: 'stop', 'emergency', 'e-stop' - Gamepad emergency button - IMU tilt detection (>45 degrees) - LiDAR obstacle detection (<0.3m) - Geofence boundary violation - Watchdog timeout trigger - MQTT remote kill signal Cascade response (within 500ms): 1. Zero cmd_vel in <50ms (priority critical) 2. Disable autonomous mode 3. Face alert animation (emergency_stop) 4. LED red indicator 5. TTS alert announcement 6. Event logging + sensor snapshot Safety properties: - Cannot be overridden once triggered - Manual resume only (gamepad Start or voice 'resume') - Non-blockable execution (separate thread) - Redundant trigger sources for reliability Published topics: - /saltybot/estop_active (Bool) - System state - /saltybot/estop_event (String) - Event log (JSON) Subscribed triggers: - /camera/imu - Tilt detection - /scan - Obstacle detection <0.3m - /voice/command - Voice e-stop/resume - /gamepad/emergency, /gamepad/start - Gamepad controls - /saltybot/geofence_violation - Geofence boundary - /saltybot/watchdog_timeout - Watchdog signal - /saltybot/mqtt_kill - Remote kill signal Package structure: - estop_server: Main emergency stop node - estop_config.yaml: Timing, triggers, cascade config - estop.launch.py: Launch with safety parameters - Unit tests for trigger detection and cascade timing Logging: /home/seb/saltybot-data/estop/ (JSON format) Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
Jetson Nano — AI/SLAM Platform Setup
Self-balancing robot: Jetson Nano dev environment for ROS2 Humble + SLAM stack.
Stack
| Component | Version / Part |
|---|---|
| Platform | Jetson Nano 4GB |
| JetPack | 4.6 (L4T R32.6.1, CUDA 10.2) |
| ROS2 | Humble Hawksbill |
| DDS | CycloneDDS |
| SLAM | slam_toolbox |
| Nav | Nav2 |
| Depth camera | Intel RealSense D435i |
| LiDAR | RPLIDAR A1M8 |
| MCU bridge | STM32F722 (USB CDC @ 921600) |
Quick Start
# 1. Host setup (once, on fresh JetPack 4.6)
sudo bash scripts/setup-jetson.sh
# 2. Build Docker image
bash scripts/build-and-run.sh build
# 3. Start full stack
bash scripts/build-and-run.sh up
# 4. Open ROS2 shell
bash scripts/build-and-run.sh shell
Docs
docs/pinout.md— GPIO/I2C/UART pinout for all peripheralsdocs/power-budget.md— 10W power envelope analysis
Files
jetson/
├── Dockerfile # L4T base + ROS2 Humble + SLAM packages
├── docker-compose.yml # Multi-service stack (ROS2, RPLIDAR, D435i, STM32)
├── README.md # This file
├── docs/
│ ├── pinout.md # GPIO/I2C/UART pinout reference
│ └── power-budget.md # Power budget analysis (10W envelope)
└── scripts/
├── entrypoint.sh # Docker container entrypoint
├── setup-jetson.sh # Host setup (udev, Docker, nvpmodel)
└── build-and-run.sh # Build/run helper
Power Budget (Summary)
| Scenario | Total |
|---|---|
| Idle | 2.9W |
| Nominal (SLAM active) | ~10.2W |
| Peak | 15.4W |
Target: 10W (MAXN nvpmodel). Use RPLIDAR standby + 640p D435i for compliance.
See docs/power-budget.md for full analysis.