Description The main chip of this item is GY 213V HTU21DThe HTU21D is a low cost easy to use highly accurate digital humidity and temperature sensor This sensor is ideal for environmental sensing and data logging and perfect for a weather stations or humidor control systems All you need is two lines for I2C communication andyoull have relative humidity readings and very accurate temperature readings as a bonus There are only four pins that need to be hooked up in order to startusing this sensor in a project one for VCC one for GND and two data lines for I2C communication This board has built in 4 7k pull up resistors for I2C communications If youre hooking up multiple I2C devices on the same bus you may want to disable these resistors Dimensions 0 6 x 0 6Package included 3 x I2C GY 213V HTU21D Temperature Humidity Sensor