01DHT22 vs DHT11
- Temp: -40 to 80 °C (±0.5 °C).
- Humidity: 0–100% (±2–5%).
- Read once every 2 seconds.
- Single 3.3–5V data line + 10 kΩ pull-up.
02Wiring
VCC → 3.3V or 5V, GND → GND, DATA → any GPIO. Add a 10 kΩ resistor between DATA and VCC.
03Code
Install the 'DHT sensor library' by Adafruit, call dht.readTemperature() and dht.readHumidity(). Check for NaN to detect timeouts.
04Use cases
- Greenhouse monitoring.
- Smart-home dashboards.
- Server-room alerts.
