4 replies to this topic

[Omar (OZ)]

Hello, I made an interrupt port for use with a button.Sometimes when I press the button it triggers the interrupt event twice or thrice. What is wrong?

[Chris Walker]

Hi Omar, This sounds like "glitching," which is pretty common in buttons. Two options: 1. Set the GlitchFilter property to true in the InterruptPort constructor. 2. If the built-in GlitchFilter doesn't offer enough debouncing, add a bit of extra circuitry to your button circuit to smooth things out. Or add in additional software-based glitch filtering (i.e. ignore any signals until they're stable for a millisecond or such). Chris

[klotz]

I found that when using the tactile miniswitches, http://www.sparkfun.com/products/97 , if I add a 0.1 mF cap from the signal line to gnd and enable the pull-up resistor cleans up the interupts just fine.

[Omar (OZ)]

I found that when using the tactile miniswitches, http://www.sparkfun.com/products/97 , if I add a 0.1 mF cap from the signal line to gnd and enable the pull-up resistor cleans up the interupts just fine.

Thanks I'll try that

[Omar (OZ)]

Hi Omar,

This sounds like "glitching," which is pretty common in buttons.

Two options:
1. Set the GlitchFilter property to true in the InterruptPort constructor.
2. If the built-in GlitchFilter doesn't offer enough debouncing, add a bit of extra circuitry to your button circuit to smooth things out. Or add in additional software-based glitch filtering (i.e. ignore any signals until they're stable for a millisecond or such).

Chris

Tried #1, it didn't help much, I added software-based glitch filtering and that helped quite a bit, thanks