In this chapter, we started with the process of selecting a sensor, in which we got to know that the sensor selection process is not as easy as it looks. There can be so many parameters, and none of them should be neglected while selecting a sensor. This affects the system according to the criticality of the application.

Following the explanation to introduction of the DHT and LDR sensors, you continued to learn with the tricky DHT sensors. The timing diagram was somewhat complex to implement. Due to lack of onboard analog-to-digital convertor, you learned about the RC time constant and use of the capacitor to integrate any resistive sensor with the RasPi and the LDR sensor in particular. Finally, we integrated everything and made a project that can be called a small project of home automation. We were able to integrate the LDR and DHT sensors and make a sensor node using the RasPi. Using the data of temperature and light captured from sensors, we controlled the appliances such as...