- It is a sensor device that senses the humidity and temperature and measures the humidity values.
- To measure the humidity it uses the capacitive sensor element and for temperature, it uses the NTC thermistor.
Working of DHT22
- To transfer data to the microprocessor unit it uses a single wire interface.
- To transfer the data to the sensor the DATA pin is connected to the microprocessor with DHT22.
- This sensor has an 8-bit microcontroller connected for calculation and its module has 3 pin package whereas the sensor has 4 pin package.
Pin configuration of DHT22
| Pins | Description |
|---|---|
| Pin-1 | VDD- is the power supply pin. DC voltage is applied to his pin. |
| Pin-2 | DATA/SDA- is the serial data pin. This pin is connected to the microcontroller to transfer data from the sensor to the controller. |
| Pin-3 | NC- is also known as the no connection pin which is left unconnected. |
| Pin-4 | GND is the ground pin. This pin is connected to the ground. |
Application of DHT22
- DHT22 is used for Testing and Inspection purposes for measuring temperature and humidity values.
- DHT22 sensor is used in home appliances and consumer products for measuring temperature and humidity values.
- DHT22 is used in medical units to detect the humidity values in isolation units of patients.