Drive a real RC car from anywhere in the world through your browser. Experience low-latency control (~30-100ms over 4G) with live first-person video streaming, powered by WebRTC peer-to-peer technology.

The system streams 720p @ 60fps video from a camera mounted on the car while you control it through a web interface. A Raspberry Pi handles video streaming and relays your control inputs. For cars with integrated ESC/receivers (like ARRMA), an ESP32 with a DAC simulates joystick inputs on the transmitter.

┌─────────────┐      WebRTC       ┌─────────────┐      WiFi/UDP      ┌─────────────┐
│   Browser   │ ◄───────────────► │ Raspberry Pi│ ◄────────────────► │    ESP32    │
│  (Control)  │   Video + Data    │  (on car)   │   Control relay    │(transmitter)│
└─────────────┘                   └─────────────┘                    └─────────────┘
                                        │
                                   Camera Module
                                   720p @ 60fps

Latency: ~30-100ms control (internet), ~150ms video glass-to-glass over 4G

• Low-latency control — ~30-100ms over internet, ~10-15ms on LAN
• Live FPV video — 720p @ 60fps H.264 streaming
• Gamepad support — Steam Deck, Xbox, PlayStation controllers via Gamepad API
• Touch & keyboard controls — Works on mobile and desktop
• Auto-reconnect — Handles connection drops gracefully

• Turbo mode (E key) — Boost from 30% → 65% forward throttle
• Traction control (Q key) — IMU + wheel RPM slip detection with auto throttle limiting
• Stability control (R key) — Yaw-rate based oversteer/understeer intervention
• ABS (B key) — Anti-lock braking with ESC state machine for controlled stops
• Hill Hold (G key) — Automatic brake hold on inclines with pitch detection
• Coast Control (N key) — Throttle injection during coasting to prevent rollback
• Surface Adaptation (F key) — Dynamic grip estimation for threshold adjustment
• Steering shaper — Speed-based steering limits and counter-steer assist

• GPS — Real-time position, speed (km/h), and heading
• IMU compass (BNO055) — Stable heading even when stopped
• Hall effect wheel sensor — RPM and distance tracking
• Track map overlay — Mini-map showing live car position
• Back camera PiP — Optional rear view from IP camera (RTSP via MediaMTX)
• Debug overlay (C key) — Real-time stability system telemetry

• Admin dashboard — Race management, player monitoring
• Race state machine — Countdown → racing → stop flow
• Token-based access — Secure, time-limited access tokens
• YouTube Live streaming — Stream directly from admin dashboard

• Throttle limits — Enforced on the car, not browser
• Headlight control (H key) — GPIO-controlled via MOSFET

This project was designed for ARRMA vehicles with integrated ESC/receivers (Big Rock, Granite, Senton, etc.) where you can't tap into the receiver directly. The workaround: an ESP32 on the transmitter generates analog voltages that mimic joystick movements.

For standard RC cars with separate receivers, you can simplify by controlling servos/ESC directly from the Pi using PWM — no ESP32 or transmitter needed.

Power: ARRMA Big Rock ESC has 5V output pins that can power the Pi directly.

Total: ~$60-80 depending on optional sensors

• Arduino IDE — For ESP32 firmware
• Node.js 18+ — For Cloudflare deployment
• Cloudflare Account — Free tier (Workers, Tunnel, TURN)

1. Copy main/config.h.example → main/config.h and add your WiFi credentials
2. Install Adafruit MCP4728 library in Arduino IDE
3. Upload main/main.ino to your ESP32
4. The ESP32 will broadcast a beacon on UDP port 4211

1. Flash Raspberry Pi OS Lite (64-bit) and enable SSH
2. Install dependencies:

   sudo apt update && sudo apt install -y python3-pip
   pip3 install aiortc aiohttp pyyaml pyserial pynmea2

3. Install MediaMTX for video streaming
4. Install cloudflared and create a tunnel
5. Deploy control-relay.py as a systemd service

1. Get TURN credentials from Cloudflare Dashboard → Calls → TURN Keys
2. Deploy the Worker:

   cd arrma-relay && npm install
   npx wrangler secret put TURN_KEY_ID
   npx wrangler secret put TURN_KEY_API_TOKEN
   npm run deploy

3. Copy public/config.js.example → config.js and configure your URLs

TOKEN_SECRET="your-secret-key" node generate-token.js 60

See SETUP.md for detailed configuration instructions.

1. Power on the RC car (ESP32 and Pi should auto-connect to WiFi)
2. Wait ~30 seconds for services to start
3. Open your Worker URL in a browser
4. Enter the access token
5. Once video connects, click "Ready"
6. Wait for admin to start the race (3-2-1-GO countdown)
7. Drive!

To use the Steam Deck's built-in controls with the browser interface:

1. Add browser as a non-Steam game

In Desktop Mode, open Steam → Games → Add a Non-Steam Game → select your browser (Firefox or Chrome).

2. Configure fullscreen launch

Right-click the browser in your library → Properties → set Launch Options:

# Firefox
--kiosk "https://your-relay.workers.dev/"

# Chrome
--app="https://your-relay.workers.dev/" --start-fullscreen

3. Grant joystick permissions to Flatpak browser

Flatpak browsers need access to /run/udev for gamepad detection:

# List installed Flatpak apps to find your browser ID
flatpak list --app

# Grant udev access (use the actual app ID from above)
flatpak override --user --filesystem=/run/udev:ro org.mozilla.firefox
# or for Chrome:
flatpak override --user --filesystem=/run/udev:ro com.google.Chrome

4. Configure controller layout

In Game Mode, select the browser → Controller icon (🎮) → select "Gamepad with Mouse Trackpad" template, or start from "Gamepad" template and manually set:

• Right Trackpad → Mouse behavior (for UI interaction before race starts)
• Left Trackpad → Mouse behavior (optional)

This lets you click buttons and navigate the UI with the trackpad while using sticks/triggers for driving.

5. Launch from Game Mode

Switch to Game Mode and launch the browser from your library. The Gamepad API will now detect the Steam Deck controls.

Access /admin.html (requires basic auth) to:

• Monitor ESP32 status and player connection
• Set throttle limits (10-50%)
• Start/stop races with countdown
• Kick players and revoke tokens
• Generate new access tokens
• Control YouTube Live streaming

• Throttle limits — Admin-adjustable 10-50%, ESP32 hard limit 50% forward / 30% reverse
• Traction control — Automatic slip detection with throttle limiting (max 30% cut)
• Auto-neutral — Car stops if connection lost (80ms hold, then neutral)
• Slew rate limiting — Prevents sudden jerky movements
• Token expiration — Tokens expire automatically
• Race state control — Controls blocked until admin starts race

arrma-remote/
├── main/                    # ESP32 firmware
│   ├── main.ino
│   └── config.h.example
├── arrma-relay/             # Cloudflare Worker
│   ├── src/index.ts
│   └── public/              # Web UI (index.html, admin.html)
├── pi-scripts/              # Raspberry Pi scripts
│   ├── control-relay.py     # WebRTC → UDP relay
│   ├── bno055_reader.py     # IMU driver
│   ├── hall_rpm.py          # Wheel RPM reader
│   ├── low_speed_traction.py # Traction control (launch/cruise phases)
│   ├── abs_controller.py    # ABS with ESC state machine
│   ├── hill_hold.py         # Hill hold with pitch detection
│   ├── coast_control.py     # Coast throttle injection
│   ├── surface_adaptation.py # Dynamic grip estimation
│   └── deploy.sh            # Quick deploy to Pi
├── restreamer/              # YouTube restreamer (Go/Fly.io)
├── generate-token.js        # Access token generator
├── SETUP.md                 # Detailed setup guide
└── PLAN.md                  # Architecture & roadmap

# ESP32-WROOM DevKit:
GPIO 21 (SDA) → MCP4728 SDA
GPIO 22 (SCL) → MCP4728 SCL

# ESP32-C3 Super Mini:
GPIO 8 (SDA)  → MCP4728 SDA
GPIO 9 (SCL)  → MCP4728 SCL

# Common:
3.3V → MCP4728 VCC
GND  → MCP4728 GND
MCP4728 LDAC → GND

VoutA → Throttle joystick wiper
VoutC → Steering joystick wiper
GND   → Transmitter GND (common ground!)

MIT License — See LICENSE for details.

Contributions welcome! Please read PLAN.md for architecture details and roadmap.

• aiortc - Python WebRTC
• MediaMTX - Media streaming server
• Cloudflare - TURN, Workers, and Tunnel services

If you find this project exciting, consider supporting my work with a small donation