Temperature and Humidity Sensor

Si7021 is an integrated sensor that measures both temperature and relative humidity with good accuracy. The resolution of measured parameters can be selected through software between 8-12 bits for humidity and 12-14 bits for temperature. The sensor uses a digital I2C interface for data transmission, so we can easily interface with it using the Wire library.

Fig. 1: SI7020 and its connections to the the AVR microcontroller

We will need to use a dedicated library written specially for it. Download the library from here and unzip its contents into the folder named Arduino\libraries or use Arduino IDE's Add ZIP Library command.

Next tutorial will teach you how to implement a barometer!