Datasheet

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 analogue input pins needed). It’s 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.

Compared to the DHT22, this sensor is less precise, less accurate and

works in a smaller range of temperature/humidity, but it’s smaller and

less expensive.

Comes with a 4.7K or 10K resistor, which you will want to use as a

pullup from the data pin to VCC.

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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 analogue input pins needed). It’s 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.
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Technical Details:  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.