🚂 Firebase Railway TCP Proxy

TCP proxy server that converts HTTPS Firebase RTDB SSE streams to plain TCP, bypassing SSL/TLS handshake issues with Airtel M2M SIM cards.

Airtel M2M SIM cards have SSL/TLS handshake issues with Firebase HTTPS endpoints. This proxy:

• Receives plain TCP connections from ESP32 (via EC200U modem)
• Connects to Firebase RTDB using HTTPS
• Streams data back over TCP using SSE format

ESP32 → EC200U 4G Modem → Railway Proxy (TCP) → Firebase RTDB (HTTPS)

1. Push to GitHub:

   cd railway-proxy
   git add .
   git commit -m "Update server.js for relay control"
   git push origin main

2. Railway Auto-Deploy:

   • Railway will automatically detect changes
   • Build and deploy within 1-2 minutes
   • Check logs in Railway dashboard

3. Verify Deployment:

   curl http://yamabiko.proxy.rlwy.net:45343/test

   Expected response:

   ✅ Firebase Railway Proxy Running!
   Server Time: 2025-11-16T...
   Firebase: relay-test1001-default-rtdb.asia-southeast1.firebasedatabase.app
   Usage: GET /relay/{DEVICE_ID}
   

GET /test
GET /

Response: Server status and info

GET /relay/{DEVICE_ID}

Response: SSE stream of relay state changes
Format: data: ON\n\n or data: OFF\n\n

# Health check
curl http://yamabiko.proxy.rlwy.net:45343/test

# Stream relay state for device
curl http://yamabiko.proxy.rlwy.net:45343/relay/dev_mhlj9n2msbwqu6bno

1. Flash esp32-firmware/relay_control_railway_proxy.ino
2. Open Serial Monitor (115200 baud)
3. Wait for connection confirmation
4. Change relay state in Firebase:
   • Path: /devices/dev_mhlj9n2msbwqu6bno/relay
   • Value: "ON" or "OFF"
5. ESP32 should respond within 1-2 seconds

{
  "devices": {
    "dev_mhlj9n2msbwqu6bno": {
      "relay": "OFF",
      "status": {
        "lastSeen": 1700000000000,
        "online": true
      }
    }
  }
}

• PORT: Server port (auto-set by Railway)
• DEBUG: Enable debug logging (default: true)

• FIREBASE_URL: Firebase RTDB URL
• TCP_HOST: Railway proxy hostname
• TCP_PORT: Railway TCP port (45343)

Railway automatically captures logs. To view:

1. Go to Railway dashboard
2. Select your project
3. Click on "Logs" tab
4. See real-time server logs

Problem: ESP32 can't connect to proxy

Solutions:

1. Check Railway proxy status (should show "Active")
2. Verify Railway TCP port is 45343
3. Check Airtel SIM has data connection
4. Try health check: curl http://yamabiko.proxy.rlwy.net:45343/test

Problem: Connected but no relay state updates

Solutions:

1. Verify Firebase path: /devices/{DEVICE_ID}/relay
2. Check Firebase rules allow read access
3. Update relay value in Firebase console
4. Check Railway logs for errors

Problem: Connection drops after few minutes

Solutions:

1. Check keep-alive interval (default: 30s)
2. Verify modem doesn't timeout TCP connections
3. Check Railway server logs for disconnections

• Deploy Railway proxy
• Test relay ON/OFF via SSE
• Verify ESP32 connection

• Add schedule streaming endpoint
• Update ESP32 to handle schedules
• Test schedule execution

• Add bidirectional communication
• Stream power data to Firebase
• Display in Flutter app

MIT

• Relay Control Team