Debounce an input using Arduino

This example demonstrates how to debounce an input, which means checking twice in a short period of time to make sure it’s definitely pressed. Without debouncing, pressing the button once can appear to the code as multiple presses. Makes use of the millis() function to keep track of the time when the button is pressed.

Circuit

image developed using Fritzing. For more circuit examples, see the Fritzing project page

Schematic

Code

The code below is based on Limor Fried’s version of debounce, but the logic is inverted from her example. In her example, the switch returns LOW when closed, and HIGH when open. Here, the switch returns HIGH when pressed and LOW when not pressed.

For more detail: Debounce an input using Arduino

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