AHT21 I2C Digital Temperature and Humidity Sensor Module

This AHT21 module is a small digital temperature and humidity sensor that outputs calibrated readings over standard I2C. It combines a capacitive MEMS humidity element and an on-chip temperature sensor with a dedicated ASIC, and its wide 1.8 to 6.0V supply range makes it easy to use with both 3.3V and 5V boards.

Key features

• Calibrated digital output over I2C, so no analog conversion is needed
• Typical accuracy of ±2% relative humidity and ±0.3°C
• Fine resolution: 0.024% RH and 0.01°C
• Wide 1.8 to 6.0V working voltage
• Compact 16 x 11mm board with a 4-pin 2.54mm header
• Works from -40 to 85°C

Specifications

• Sensor: AHT21
• Interface: I2C
• Working voltage: 1.8 to 6.0V
• Humidity accuracy: ±2% typical
• Humidity resolution: 0.024%
• Temperature accuracy: ±0.3°C typical
• Temperature resolution: 0.01°C typical
• Operating range: -40 to 85°C
• Module size: 16 x 11mm
• Header: 4 pins, 2.54mm pitch

In the box

• 1 x AHT21 temperature and humidity sensor module

For best accuracy, the supplier advises leaving the sensor in an environment above 80% humidity for 12 hours before first use. Build a logger with our Raspberry Pi weather station tutorial.