The DHT11 sensor is made of two parts, the capacitive humidity sensor and the thermistor. There is also a basic chip inside that converts the analog signal to a digital signal with the temperature and the humidity.The digital signal is easy to read using a microcontroller. The result is shown on a LCD display.

Specifications DHT11

  • Ultra low cost
  •  3V to 5V power and I/O
  • 20% to 80% humidity reading with 5% accuracy
  • 0°C to 50°C temparature reading with 2°C accuracy
  • sample reading once every second.

The DHT11 has four pins to connect to a microocntroller:

pin  Signal 
 1  VCC 5V
 2  Data out
 3  Not connected, not used.
3 Ground