Python Robotics Projects

Interfacing the PIR sensor

So far, so good! In this unit, we will go ahead and interface out first sensor, which is a passive infrared, commonly known as a PIR sensor. This sensor is a very special sensor and is used very commonly in automation projects. Its low energy consumption makes it a superb contender for IoT projects as well. So let's see how it works.

You must have noticed that when we heat a metal to a high temperature, it slowly gets dark red in color, and when we heat it further, it gets brighter and slowly goes from red to yellow as depicted in the below diagram which shows a red hot steel tab. Now, as the temperature increases, the wavelength of the emitted radiation decreases; that is why with the increase in temperature the ...