AHT20 and BMP280 digital temperature, humidity and air pressure sensor

This small module carries two sensors: the AHT20 measures temperature and humidity, the Bosch BMP280 measures air pressure and temperature. Both are on the same I2C bus, so two signal lines are enough to read them. The air pressure can also be used to determine altitude. The module works with 2 to 5 V.

Features:

• AHT20: temperature ±0.3 °C, humidity ±2 % RH
• BMP280: air pressure 300 to 1100 hPa
• Both sensors on one I2C bus, AHT20 at address 0x38
• Compact size 16 × 16.5 mm

Application Examples:

• Weather station with temperature, humidity and air pressure
• Monitoring the indoor climate
• Altitude measurement via air pressure
• Integration into Home Assistant with ESPHome

Documentation:

• AHT20 Arduino library (Adafruit, GitHub)
• BMP280 Arduino library (Adafruit, GitHub)
• ESPHome documentation: BMP280 Temperature+Pressure Sensor
• ESPHome documentation: AHT10 Temperature+Humidity Sensor

Technical Data:

• Sensors: AHT20, BMP280
• Interface: I2C, AHT20 address 0x38
• Operating voltage: 2 to 5 V DC
• Air pressure: 300 to 1100 hPa, resolution 0.18 Pa, absolute ±1 hPa (BMP280)
• Humidity: 0 to 100 % RH, ±2 % RH, resolution 0.024 % RH, repeatability ±0.1 % RH, response time 8 s, long-term drift below 0.5 % RH per year
• Temperature: -40 to 85 °C, ±0.3 °C, resolution 0.01 °C, repeatability ±0.1 °C, response time 5 to 30 s, long-term drift below 0.04 °C per year
• Dimensions: 16 × 16.5 × 3 mm
• Weight: 4 g

Scope of Delivery:

• 1× AHT20 and BMP280 digital temperature, humidity and air pressure sensor
• 1× 4-pin header