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03/23/10 14:16
Modified:
  03/23/10 16:32

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#174426 - switch input > interrupt (debouncing)
it has come to the time to put my electronics on a PCB, however I wish to make one addition, a connector block with debouncing so that switches can be put into the system at a later date connected to the interrupts...

my dillema is that the interrupts are falling edge triggered and the debouncing buffers I have found give outputs toggling low to high upon the press of a button, for example this maximchip. I assume that it would not work in the same way if i simply swapped the switch and the pull up resistor, due to the logic, or would it. (i just assume that the logic for the rsising edge of the outpu - debouncing the contacts closing, is not used in the same way for the contacts opening - falling edge of the output). Or can I use this method with a cleverly chosen switch?

so my first question is, am i correct in my above assumptions, and secondly is there a debounce IC out there that can be falling edge triggered (I would not like to invert my oputput, but I suppose if there is not other way I am going to have to!)

thanks for any advice you can give, or a magical IC that exists I have not found!

List of 18 messages in thread
TopicAuthorDate
switch input > interrupt (debouncing)            01/01/70 00:00      
   double post            01/01/70 00:00      
      Why the extra hardware?            01/01/70 00:00      
         wow            01/01/70 00:00      
            other ISR recommendation            01/01/70 00:00      
         or the other solution (my favorite)            01/01/70 00:00      
            using timer            01/01/70 00:00      
               Some switches have very long bounce time            01/01/70 00:00      
                  a lot depends on the switches themselves            01/01/70 00:00      
                     which is a $#@!! disaster            01/01/70 00:00      
                        Remember that there is more than push buttons out there            01/01/70 00:00      
                        What about the others?            01/01/70 00:00      
                           Majority of implementations synchronizes with key down            01/01/70 00:00      
                              Now I'm confused ...            01/01/70 00:00      
                                 Not Sure About The Code            01/01/70 00:00      
                                    More info on PC keyboard            01/01/70 00:00      
            Short spikes            01/01/70 00:00      
   The real problem with debouncing            01/01/70 00:00      

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