Author Topic: Is it worth debouncing an external tap tempo switch?  (Read 307 times)

ianmgull

Is it worth debouncing an external tap tempo switch?
« on: March 16, 2021, 07:50:14 PM »
I have a Boss ES-8 switching system. I'm building a simple external foot switch with a normally closed momentary stomp switch. 90% of the time, it will act as a tap tempo switch.

Is it worth adding a debouncing circuit to a switch like this? Or would you consider it good enough as is?

FWIW, the control voltage is just a 3.5v DC signal.

iainpunk

Re: Is it worth debouncing an external tap tempo switch?
« Reply #1 on: March 16, 2021, 08:11:58 PM »
if its a momentary switch instead of a latching switch, its only one cap and resistor, its totally worth doing!
if its a latching switch, don't bother
half man - half snail - 6 feet to scale - Snail man's - not frail - He's been - to jail - snail man is fuccing real
『snailpilled』

ianmgull

Re: Is it worth debouncing an external tap tempo switch?
« Reply #2 on: March 16, 2021, 08:25:15 PM »
Hey thanks.

I was under the impression that it was much more complicated than that. Do you know of a schematic that shows how this is put together?

iainpunk

Re: Is it worth debouncing an external tap tempo switch?
« Reply #3 on: March 16, 2021, 08:38:32 PM »


half man - half snail - 6 feet to scale - Snail man's - not frail - He's been - to jail - snail man is fuccing real
『snailpilled』

ianmgull

Re: Is it worth debouncing an external tap tempo switch?
« Reply #4 on: March 16, 2021, 08:42:27 PM »
Easy enough. Thanks!!

iainpunk

Re: Is it worth debouncing an external tap tempo switch?
« Reply #5 on: March 16, 2021, 09:02:14 PM »
if it still jitters or has problems, just increase the resistor tenfold, try the same trick if it still has problems after that.

cheers
half man - half snail - 6 feet to scale - Snail man's - not frail - He's been - to jail - snail man is fuccing real
『snailpilled』

ianmgull

Re: Is it worth debouncing an external tap tempo switch?
« Reply #6 on: March 16, 2021, 09:39:59 PM »
Ok, so I just realized that I don't understand this schematic.

The signal is on a TS cable. So there's a 3.5v source and a ground. This means the what is labeled 'output' in the schem is actually ground. So does that mean the grounded end of the resistor and cap are actually connected to the output?

11-90-an

Re: Is it worth debouncing an external tap tempo switch?
« Reply #7 on: March 16, 2021, 09:52:26 PM »
perhaps try something like this then...





flip flop flip flop flip

composition4

Re: Is it worth debouncing an external tap tempo switch?
« Reply #8 on: March 16, 2021, 10:50:34 PM »
That won't work, the cap need some series resistance to have any debouncing effect

ianmgull

Re: Is it worth debouncing an external tap tempo switch?
« Reply #9 on: March 17, 2021, 08:22:46 AM »
My understanding was that a simple debounce circuit is just an RC Lowpass filter? If that's the case, I wonder what series resistance to use without causing too much of a drop for the logic switching to do its job.

ElectricDruid

Re: Is it worth debouncing an external tap tempo switch?
« Reply #10 on: March 17, 2021, 09:36:32 AM »
I suspect the normally-closed switch will be more of a problem that the debouncing. Most tap-tempo switches and similar are normally-open, and if I was designing an input for such a thing, I'd make sure to include debouncing either in my input socket hardware or in firmware after that.

I'd try it and see. Don't fix it if it isn't broken.