The DHT11 is a low-cost digital basic temperature and humidity sensor. It uses a capacitive humidity sensor and a thermistor to measure the ambient air and spits a digital signal on the data pin (no analog input pin required). It is quite simple to use, but requires careful timing to enter the data. The only real disadvantage of this sensor is that you can only get new data once every 2 seconds, so when you use our library, sensor readings can have up to 2 seconds.

Compared to the DHT22, this sensor is less accurate and operates in a smaller temperature/humidity range, but it is smaller and less expensive.

Comes with a 4.7K or 10K resistor, which you can use as a pullup of the VCC data pin.


Technical details

    Low cost
    Power supply 3 to 5V and I/O
    2.5mA max. operating current during conversion (when requesting data)
    Good for humidity readings of 20-80% with 5% accuracy.
    Good for temperature readings from 0-50°C with an accuracy of ±2°C
    Not more than 1 Hz sampling frequency (once per second)
    Body size 15.5mm x 12mm x 12mm x 5.5mm
    4 pins spaced 0.1 in. apart

Documentation

DHT11, DHT22 and AM2302 Sensors