The data that is the reading of the temperature and humidity is provided over the single terminal called the Data bus. The DHT11 temperature and humidity sensor measures temperature using NTC (Negative temperature measurement co-efficient) temperature measurement component and on the other measures humidity using resistive-type humidity measurement component. The DHT11 sensor is digital that is provides data in digital form it is opposite to thermistor whose values for temperature measurement are analog in nature. It is important to note here that this sensor measures both the temperature and humidity simultaneously that is on each request for data from the microcontroller the DHT11 sensor generates the data packets containing the information about both the temperature and humidity.

Before diving deep into the discussion on the interfacing of the Arduino microcontroller development board and DHT11 sensor let us first what the DHT11 sensor is? DHT11 sensor is used to measure the temperature and humidity of the surroundings in which it is installed.