He’s provided a wiring diagram in the repository along with the Arduino code for the ESP8266, but the hardware side of this demonstration really isn’t that important.

He decided to take an in-depth look at the DHT11 sensor; which you can get your hands on for under $3 if you know where to look. The four-pin device uses a 1-wire protocol.

To build your very own IoT rain checking system, you will need a Raspberry Pi 3 Model B, a DHT11 Temperature & Humidity Sensor (4 pins), and a raindrop sensing board, which can be purchased for ...