Arduino: A Quick-Start Guide, 2nd Edition

Working with Buttons

In this section you’ll learn how pushbuttons work in principle and how you can use them with an Arduino. We’ll start small and build a circuit that uses a pushbutton to control a single LED.

What exactly is a pushbutton? The following figure shows three views of a typical pushbutton. It has four connectors that fit perfectly on a breadboard (at least after you have straightened them with a pair of pliers). Two opposite pins connect when the button is pushed; otherwise, they are disconnected.

The following picture shows a simple circuit using a pushbutton. Connect pin 7 (chosen completely arbitrarily) to the pushbutton, ...