Capacitor value for noise .1 or .01 and why?

[Fastest1]

I am presently not running any caps in my inputs from my probe or touch plate. During probing routines sometimes it errors out if the debounce is less than say 250. I am wondering if I use the cap between power and ground on the input line for the probe. Can I lessen the debounce after installing it. And does it lengthen the reponse time as the debounce does or quell the noise some other way?

[Fastest1]

Well I installed the .1uf cap and set my debonce to 0, so far so good. Wasnt particularly noisy before just trying to rule out any errant signals. Previously ran the debounce between 50-100.

[neilw20]

Put it right at the terminals on the PCB.
One side to the input, the other to the 0v - Shall we call it ground?
Logic 0v that is.
Don't put the cap from the input to the supply. That will make things worse, in all likelihood.
0.1 or 0.01 is OK. Either will do. I would go for 0.1 disc ceramic.
Try debounce 0, but 250 will be OK. If it needs to be non-zero, then find the minimum value that works, then at least double it.

[Fastest1]

neil, thanks for the reply. I did use a .1uf cap between the pin and the ground as it is referred to on the Hobby Pro Cnc board though you are probably correct in that it is the 0v point. My debounce is set to 0 at the moment and all seems well. If I ever finish reading this article about time constraints someone on another forum referred me to. http://www.electronics-tutorials.ws/rc/rc_1.html
It is pretty heavy reading for me but it does explain the relationship of the parts pretty well it appears. Maybe I will be able to move down to a .01 and get even better results.

[neilw20]

It is working well? Leave it at 0.1
0.01 most likely will only get worse, and you won't know.
If it ain't broke, don't fix it.

[Fastest1]

Originally Posted by neilw20 If it ain't broke, don't fix it.

But how would you know if it operating at its maximum potential? With that attitude, you would think any car, motorcycle, bicycle, skateboard or pair of running shoes would have been fast enough right out of the box, but NOOOO not around here! Didnt you ever add goodies to your parents cars when you borrowed them for the night? Lucky they didnt have a blower sticking out of the hood of the station wagon when they woke up.

[neilw20]

Set up a dial indicator, and keep repeating the zeroing process and MEASURE the variations.
Keep reducing the capacitor, and try to figure if it does anything.
And do the same for the debounce.
Make a silk purse out of a sows ear if you wish or use a heap of technology and analyze what you have.
Is it reliable? If you are not confident in your equipment, find out why, or declare what 'good enough' is.

[Fastest1]

You were right and I was just kidding. It seems to be working just fine, no stops for unknown reasons. The debounce is set to 0 now. I havent tried repeatability yet.