sl-controls
4fed80f36d
Adds saltyrover_drive ROS2 package — 4-wheel differential drive controller
for the stable SaltyRover chassis (no balance PID required).
rover_drive_node:
- Subscribes /cmd_vel (Twist), converts to left/right wheel speeds
- Tank-style kinematics: v_left = linear.x - angular.z × sep/2
- FL/RL share left speed, FR/RR share right speed (paired axles)
- Publishes /rover/wheel_speeds (JSON: {"cmd":"drive4","fl":N,"fr":N,"rl":N,"rr":N})
- Trapezoidal ramp: accel 2.0 m/s², decel 4.0 m/s² (stable chassis allows faster ramps)
- cmd_vel watchdog (0.5s timeout → zero speeds)
- max_speed 3.0 m/s (±1000 STM32 ticks)
rover_odom_node:
- Dead-reckoning odometry from /cmd_vel (encoder-ready for future HW)
- Publishes /odom (nav_msgs/Odometry) + TF odom→base_link
- Forward Euler pose integration at 50 Hz
52/52 unit tests: kinematics, int scaling, JSON builder, full pipeline,
trapezoidal ramp, odometry integration, quaternion conversion.
Co-Authored-By: Claude Sonnet 4.6 <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.