Has anyone had experience reading a slot opto detector with Pic18F?
I am wondering if it has been found necessary to do SW de-bounce on these typically.
The disc is a 4 slot with 5ms between pulses, the input is the INT0 active high that has Schmidt trigger in this mode.
The waveform looks quite noise free on the scope, however I would be interested if anyone has seen any problems?
Max.

 

I've never needed to debounce an opto sensor in rotational (motor or human driven) uC applications.
What would be the 'bounce' mechanics to generate a glitched signal with a typical Schmidt trigger conditioned input.

 

I read of one such project that felt it was needed, although Schmidt trigger, if the bounce were to last any considerable time it would generate another interrupt.
They mentioned they had experienced 'noise' on the input.
I wanted to get a feel if this was anyone's previous experience.
I will try without and see if there is a problem.
Max.

 

A "bounce" is usually caused when mechanical contacts close ( and sometimes when they open).
Since you have no mechanical contacts in your circuit, I see no source for a bounce glitch.

 

Schmitt trigger input should take care of any slow rise or fall times.

 

Schmitt trigger input should take care of any slow rise or fall times.

But if a rising edge bounce is seen after the INT is taken care of it is another pulse.
The consensus seems to be I was a may have been a little paranoid!
I will go ahead without it.
Thanks all.
Max.