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• power supply： 3.3~5.5v dc• output： 4 pin single row• measurement range： Humidity 20-90%rh， temperature 0~50℃• accuracy： Humidity +-5%rh， temperature +-2℃• resolution： Humidity 1%rh， temperature 1℃• interchangeability： Fully interchangeable• long-term stability： <±1%rh/yearConnections:1. Vcc connected to +3.3v~5v2. Data connected to the microcontroller io port3. Gnd connected to ground
