In the previous chapter, we understood how GPIOs are used for output. But, as the name suggests, the GPIO can be used for both input and output purposes. In this chapter, we will see how you can go ahead and use these pins to input the data over to Raspberry Pi.

The topics which we will cover in this chapter are:

• A deeper dive into GPIOs
• Interfacing the PIR sensor
• Interfacing the ultrasonic proximity sensor
• Interfacing through I2C