The DHT22 is a basic, low-cost digital temperature and humidity sensor. It uses a capacitive humidity sensor and a thermistor to measure the surrounding air, and spits out a digital signal on the data pin (no analog input pins needed).
It’s fairly simple to use, but requires careful timing to grab data. The main difference between this sensor and the DHT11 is that the DHT22 is more precise, more accurate and works in a bigger range of temperature/humidity, but it is larger and more expensive.
Specifications
- Power supply: 3.3-5.5V DC
- Output signal: digital signal via single-bus
- Sensing element: Polymer capacitor
- Operating range:
- Humidity: 0-100%RH
- Temperature: -40~80°C
- Accuracy:
- Humidity: ±2%RH (Max ±5%RH)
- Temperature: <±0.5°C
- Resolution:
- Humidity: 0.1%RH
- Temperature: 0.1°C
- Repeatability:
- Humidity: ±1%RH
- Temperature: ±0.2°C
- Humidity hysteresis: ±0.3%RH
- Long-term stability: ±0.5%RH/year
- Sensing period: Average: 2s
- Interchangeability: Fully interchangeable
- Dimensions: 15.1mm x 25mm x 7.7mm (with 4 pins, 0.1" pitch)
Pinout
- VDD: Power supply (3.3V to 5.5V)
- DATA: Serial data output
- NC: Not connected
- GND: Ground