Features
- Full range temperature compensation for accurate readings in different environments.
- Measures both relative humidity and temperature.
- Provides factory-calibrated digital output signals.
- Excellent long term stability for continuous monitoring.
- No extra components needed for operation.
- Simple 3 pin interface: VCC, GND, and DATA.
- Ultra low power consumption, ideal for battery powered systems.
Specifications
- Operating voltage: 3.3 to 5.5 V
- Operating current: measuring 0.5 mA, standby 15 uA
- Humidity range: 0 to 99.9 percent RH (accuracy ±2 percent RH)
- Temperature range: minus 40 to 80 degrees Celsius (accuracy 1 degree Celsius)
- Communication protocol: single wire serial
- Sampling period: 2 seconds
- Sensor body size: 39 x 23 mm
- Mounting hole: 3 mm
- Pin spacing: 2.54 mm
Description
The DHT22 is a precise digital sensor that combines a humidity sensing element, a thermistor, and an onboard integrated circuit. It delivers calibrated digital readings through a single data pin. The sensor is factory calibrated and requires no manual adjustment. It is not compatible with Dallas One Wire protocol, but uses its own timed data exchange method. Compared to the DHT11, the DHT22 offers a wider range, higher accuracy, and better resolution.
How It Works
- The humidity element absorbs moisture and changes resistance based on humidity levels.
- The thermistor changes resistance with temperature.
- The internal integrated circuit processes these signals and outputs calibrated digital data.
- Communication is done through a single asynchronous data line controlled by the microcontroller.
- Works with both 3.3 V and 5 V systems.
Microcontroller Interaction
- Uses 3 pins: VCC, GND, and DATA.
- Comes factory calibrated for easy setup.
- Data format: humidity integer, humidity decimal, temperature integer, temperature decimal, parity bit.
- The microcontroller pulls the data pin low briefly to request new data.
Applications
- Weather stations
- Home automation
- HVAC systems
- Greenhouse monitoring
- Data logging
- IoT devices
- Laboratory experiments
- Food storage and transport
- Industrial environment control
- Home brewing
- Climate controlled storage
- Energy efficiency projects
- Educational experiments
- Agricultural field monitoring
Features
- Full range temperature compensation for accurate readings in different environments.
- Measures both relative humidity and temperature.
- Provides factory-calibrated digital output signals.
- Excellent long term stability for continuous monitoring.
- No extra components needed for operation.
- Simple 3 pin interface: VCC, GND, and DATA.
- Ultra low power consumption, ideal for battery powered systems.
Specifications
- Operating voltage: 3.3 to 5.5 V
- Operating current: measuring 0.5 mA, standby 15 uA
- Humidity range: 0 to 99.9 percent RH (accuracy ±2 percent RH)
- Temperature range: minus 40 to 80 degrees Celsius (accuracy 1 degree Celsius)
- Communication protocol: single wire serial
- Sampling period: 2 seconds
- Sensor body size: 39 x 23 mm
- Mounting hole: 3 mm
- Pin spacing: 2.54 mm
Description
The DHT22 is a precise digital sensor that combines a humidity sensing element, a thermistor, and an onboard integrated circuit. It delivers calibrated digital readings through a single data pin. The sensor is factory calibrated and requires no manual adjustment. It is not compatible with Dallas One Wire protocol, but uses its own timed data exchange method. Compared to the DHT11, the DHT22 offers a wider range, higher accuracy, and better resolution.
How It Works
- The humidity element absorbs moisture and changes resistance based on humidity levels.
- The thermistor changes resistance with temperature.
- The internal integrated circuit processes these signals and outputs calibrated digital data.
- Communication is done through a single asynchronous data line controlled by the microcontroller.
- Works with both 3.3 V and 5 V systems.
Microcontroller Interaction
- Uses 3 pins: VCC, GND, and DATA.
- Comes factory calibrated for easy setup.
- Data format: humidity integer, humidity decimal, temperature integer, temperature decimal, parity bit.
- The microcontroller pulls the data pin low briefly to request new data.
Applications
- Weather stations
- Home automation
- HVAC systems
- Greenhouse monitoring
- Data logging
- IoT devices
- Laboratory experiments
- Food storage and transport
- Industrial environment control
- Home brewing
- Climate controlled storage
- Energy efficiency projects
- Educational experiments
- Agricultural field monitoring
