Digital Temperature and Humidity Sensor (DHT11)

Description: The DHT11 is a basic, ultra 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). Its fairly simple to use, but requires careful timing to grab data. The only real downside of this sensor is you can only get new data from it once every 2 seconds, so when using our library, sensor readings can be up to 2 seconds old.

FEATURES

Low cost 3 to 5V power and I/O 2.5mA max current use during conversion (while requesting data) Good for 20-80% humidity readings with 5% accuracy Good for 0-50°C temperature readings ±2°C accuracy No more than 1 Hz sampling rate (once every second) Body size 15.5mm x 12mm x 5.5mm 4 pins with 0.1" spacing

Documents:

• DH11 Wiki
• Arduino library

Connection (DH-11 have four pins):

• VCC (3 to 5V power)
• Data out
• Not connected
• Ground

Simply ignore pin 3, its not used. You will want to place a 10K resistor between VCC and the data pin.