AM2302 DHT22 Temperature Humidity Sensor Module

The AM2302 DHT22 module is designed to operate at a nominal voltage of 5V DC. It is crucial to supply a stable 5V power source, as deviations can affect the accuracy of the digital signal output and potentially damage the integrated microcontroller.

The single-bus interface uses one data pin for bidirectional communication. Connect the module's data pin to a digital I/O pin on your microcontroller (Arduino, ESP32, etc.), with a pull-up resistor (typically 4.7kΩ to 10kΩ) to VCC. Communication involves sending a start signal from the host, followed by the sensor transmitting a 40-bit data packet containing humidity and temperature readings.

The DHT22 has a sampling period of 2 seconds. It is not recommended to request data more frequently than once every 2 seconds to ensure sensor stability and accuracy. The sensor requires a brief warm-up time after power-on before providing reliable readings.

While the DHT22 operates from -40°C to 80°C, its PCB-mounted module is not inherently waterproof. For outdoor or high-humidity applications, the sensor element must be protected from direct condensation and water ingress using an appropriate enclosure or a dedicated probe version with a sealed housing.