The DHT11 is a low-cost temperature and humidity sensor. This sensor uses a thermistor to measure the temperature. The word thermistor is a combination of thermal (temperature) and resistor because it is a type of resistor where the resistance is highly sensitive to temperature even more so than a normal resistor. The current temperature can be determined based on the output voltage of the thermistor.
When working with a thermistor, the first thing we need to do is to determine how to calculate the temperature based on the output voltage. With the TMP36 temperature sensor that we used with the prototype that was created in Chapter 4, Basic Prototyping, we could easily calculate the temperature based on the output voltage of the sensor with a basic formula of (voltage - 0.5) * 100.0 because it uses a solid-state technique to determine the temperature. This is...