Overview

This project entails adding a temperature sensor to a SONOFF S20 smart socket and adding custom firmware. I am doing this primarily to help with heating small spaces with a space heater.

Adding the Temperature Sensor

We are using a DS18B20 temperature sensor. I have found these sensors pretty reliable. This particular one is encased in an aluminum probe.

We are connecting the the DS18B20 to the TX pin which is actually the RX pin of the EP8266 chip (GPIO 3).

Custom Firmware

Our custom firmware allows you to specify a set temp and such via a web interface.

Additional Information

Desoldering the board is possible by removing the solder from the following three points and prying the board away from the case while heating the solder points. I would not recommend this unless you have really screwed things up.