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Debounce a Switch


The problem with hardware is it doesn't behave nicely. In the case of switches they don't just turn off and on. They bounce. When you push a button it will go on, then off, then on, then off, before it goes on and stays on. The common way to deal with this is to read a switch's input and if it has changed state you must ignore it for a fraction of a second. Just long enough for it to stop bouncing. Then you may reliably read it as input again.

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Copyright 1999 by Don Wells.