DHT11 Temperature and Humidity Sensor

This is a very popular, ultra low-cost digital temperature and humidity sensor. It uses a capacitive humidity sensor, and a thermostat to measure the surrounding air temperature. The result is available via a digital signal on the data pin (no analog 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. But, for most applications, this is not an issue at all. 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.