AHT10 Temperature and Humidity Sensor Module

AHT10 Temperature and Humidity Sensor Module

It is a temperature and humidity detection module using the Aht10 sensor of the Aosong company.

     The AHT10 Temperature and Humidity Sensor Module is a digital temperature and humidity measurement board with I2C communication, carrying the AHT10 sensor of Aosong (ASAIR). It measures relative humidity in the %0 - %100 RH range with typical ±%2 RH accuracy and temperature between -40°C and +85°C with typical ±0.3°C accuracy. The sensor is factory calibrated and directly gives the temperature compensated value; no calibration or analog reading is needed on the user side.

     Inside the sensor there is a capacitive humidity sensing element and a CMOS circuit that processes the measurement; the sensor is an SMD package of 5.0mm x 4.0mm x 1.6mm. On the module board, next to the sensor, there is a 3.3V regulator and a level shifter for the I2C lines; therefore the board can be used with both 3.3V and 5V supply and with control boards of 3.3V or 5V logic. On the upper edge of the board there are solder points that set the I2C address to 0x38 or 0x39; the address can be changed if it clashes with another I2C device.

     The board of about 16mm x 11mm plugs into a breadboard or a cable with female connectors through its 4-pin 2.54mm pitch connection. It is suitable for temperature and humidity reading in applications such as incubators, greenhouses, terrariums, warehouses and room climate monitoring.

Key features:

     Calibrated digital output: The sensor is factory calibrated and gives the temperature compensated humidity value digitally over I2C; the read value is converted directly to relative humidity and temperature.

     Accurate measurement: Typical ±%2 RH accuracy in humidity and typical ±0.3°C in temperature; resolution %0.024 RH and 0.01°C.

     Use with 3.3V and 5V: Thanks to the 3.3V regulator and the I2C level shifter on the board, the module connects directly to 3.3V and 5V systems.

     Selectable I2C address: The address is set to 0x38 or 0x39 with the solder point on the board; it can be changed if it clashes with another I2C device.

     Small board: The board of about 16mm x 11mm fits narrow boxes and the inside of devices; it is easily plugged in with its 4-pin connection.

Features:

• Product type:    I2C digital temperature and humidity sensor module
• Sensor: Aosong (ASAIR) AHT10
• Humidity measurement range: %0 - %100 RH
• Humidity accuracy: typical ±%2 RH
• Humidity resolution: %0.024 RH
• Temperature measurement range: -40°C to +85°C
• Temperature accuracy: typical ±0.3°C
• Temperature resolution: 0.01°C
• Humidity response time: 8s
• Temperature response time: 5s - 30s
• Communication: I2C (IIC)
• I2C address: 0x38 or 0x39 (selected with the solder point on the board)
• Supply voltage: 3.3V - 5V (3.3V regulator and I2C level shifter on the board; the AHT10 sensor itself 1.8V - 3.6V)
• Calibration: factory calibrated, temperature compensated output
• Sensing element: capacitive humidity element and CMOS measurement circuit
• Compatible boards: Arduino, ESP32, ESP8266, Raspberry Pi, STM32 and all control boards with an I2C interface
• Connection: 4 pins, 2.54mm pin pitch
• Sensor package: SMD, 5.0mm x 4.0mm x 1.6mm
• Colour: blue board
• Dimensions: about 16mm x 11mm

Usage information:

• Connect the VIN pin of the board to the 3.3V or 5V supply, the GND pin to GND, and the SCL and SDA pins to the I2C bus of the control board. Check the pin labels of the board you received before connecting.
• The address in the sensor datasheet is 0x38; the board address is 0x38 or 0x39 depending on the position of the solder point on top. Check the address with an I2C scanner before use.
• After powering up, wait a short time for the sensor to be ready; read the measurements a few seconds apart. The humidity value responds to a change in the environment in about 8s.
• After soldering the pin header, mount the board away from heat sources (regulator, heater, lamp, motor) and direct sunlight, in a place with air flow.

Areas of use:

•  Incubator humidity and temperature control
•  Greenhouse and plant growing environment monitoring
•  Mushroom growing room humidity control
•  Terrarium and reptile care environment
•  Ventilation fan and dehumidifier control
•  Air conditioning and climate automation
•  Warehouse, archive and cellar moisture monitoring
•  Weather station and datalogger projects
•  Smart home room temperature and humidity display (hygrometer, thermometer)
•  Humidity monitoring inside device boxes and electrical panels
   

Precautions:

•  The sensor is an open board and is not waterproof. Do not place it in water, rain or where water drips on it; outdoors, use it inside a box protected from rain with air flow.
•  Do not cover the small hole on top of the sensor and do not apply lacquer, glue or protective spray on it; the humidity measurement will be spoiled.
•  Do not connect the VIN and GND pins in reverse; reverse supply may permanently damage the board.
•  Aosong's AHT10 datasheet expects a single AHT10 on the I2C bus and does not describe the 0x39 address; two AHT10 on the same bus may not work reliably. If you need two sensors, use separate I2C buses or an I2C multiplexer.
•  In environments with continuous condensation, chemical vapour (solvent, ammonia, chlorine) or heavy dust the humidity reading may drift; protect the sensor from these environments.
•  The AHT10 is not suitable for instant monitoring of fast changing temperature; the temperature response time is 5s - 30s.

Package contents:

•  1 Piece AHT10 Temperature and Humidity Sensor Module
•  1 Piece 4-pin male header (not soldered)
•  Note: The connection cable and the control board are not included in the package.