Avoiding bounce in input

danielpepo · Joined: 12 Apr 2010 Posts: 5

I'm a newbie and I'm trying to learn to program with C.
What's the best way to avoid getting lots of ones when you push a button or get a signal from a sensor? interruption with RB0? or a delay? (I don't like delays because I need the program to keep running) or is there an edge function?

Thanks for your help

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

Here is a simple button debounce program:
http://www.ccsinfo.com/forum/viewtopic.php?t=19874

Here is the "Button Command" code that I wrote for the Code Library:
http://www.ccsinfo.com/forum/viewtopic.php?t=23837

Here's a version of it that polls the buttons during a timer interrupt:
http://www.ccsinfo.com/forum/viewtopic.php?t=31849

This version stores the button presses in a buffer, which can be read:
http://www.ccsinfo.com/forum/viewtopic.php?t=39585&start=1

danielpepo · Joined: 12 Apr 2010 Posts: 5

Thanks for your help.
What if using your button.c code I don't want the delay and the auto-repeat to work?
I want to make a counter which only counts once when the button is pressed, the button could stay pressed indefinitely.

danielpepo · Joined: 12 Apr 2010 Posts: 5

I just found out if I load 255 on delay, it doesn't repeat.
I couldn't understand one thing from your button code, How can you know 50 would be 500ms and so on?

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

Look in the while() loop in the main program. It has a delay_ms(10)
statement at the end. This means the counters will count in 10ms
increments. A count of 50 gives 50 x 10ms = 500 ms.