f4e4f184ef
Add WiFi mesh handoff infrastructure: WiFiState.msg interface: - SSID, signal strength (dBm), connection status - AP address, frequency, link quality - TX/RX rates, roaming flag - Available APs for handoff decision WiFi Monitor Node: - Signal monitoring via iwconfig/nmcli - Auto-roam at -70dBm threshold - Seamless wpa_supplicant roaming - Gateway ping (8.8.8.8) every 5s - USB tethering fallback if offline >30s - TTS warnings for connectivity issues - Coverage logging with AP transitions Features: - Configurable roaming threshold (-70dBm default) - Gateway connectivity verification - Offline detection with configurable timeout - USB tethering auto-activation/deactivation - Signal strength change logging (>5dBm) - AP transition logging - Manual rescan/tether control commands Topics: - /saltybot/wifi_state (String) - /saltybot/speech_text (String warnings) - /saltybot/wifi_cmd (String commands) Configuration: - interface: wlan0 - roam_threshold_dbm: -70 - offline_warning_timeout: 30.0 - target_ssid: SaltyLab - fallback_tether: true - coverage_log_file: /tmp/wifi_coverage.log Roaming Behavior: - Monitors signal continuously - When signal < -70dBm, scans for stronger AP - wpa_supplicant performs seamless handoff - Logs all AP transitions to coverage file Fallback Behavior: - Pings gateway every 5 seconds - If unreachable for >30s, activates USB tether - TTS alert: 'Warning: Lost WiFi connectivity...' - Auto-deactivates when WiFi restored Coverage Mapping: - Logs timestamp, SSID, signal, connected status - Tracks roaming events - Useful for mesh network optimization 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.