Theory :

Arduino senses the environment by receiving inputs from add-on devices such as sensors, and can control the world around it by adjusting lights, motors, and other actuators. In this class you will learn how and when to use the different types of sensors and how to connect them to the Arduino.

We all know switch is an input device and used; to make or break an electrical connection. Now let’s learn Interfacing of Switch and Arduino, Here we will use switch to take input signal to the microcontroller so that we will be able to interface more input devices to the microcontroller, like sensors output as input to microcontroller.