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The Sonoff device is a cheap $5 ESP8266 wifi enabled switch.
Pinout
| GPIO | Description |
|---|---|
| 0 | Button |
| 1 | Serial Rx and Optional Sensor |
| 3 | Serial Rx and Optional Sensor |
| 4 | Optional Sensor |
| (no pad, available at esp8266 chip) | |
| 12 | Relay and Red LED |
| 13 | Green LED |
| 14 | Optional Sensor |
Wiring the Sonoff to the serial cable
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