[sdiy] Tap tempo question

Brian Willoughby brianw at audiobanshee.com
Tue Feb 2 07:12:02 CET 2021

On Feb 1, 2021, at 16:31, Didier Leplae wrote:
> I am currently working on a delay module using a PIC uC to control the delay time so adding in a tap function. 
> Thus far, I have the PIC measuring the time between two consecutive taps to determine the delay time. But it occurred to me that sometimes when I use a tap tempo, I tap multiple times with the assumption that the multiple taps are averaged. 
> Does anyone have an opinion on which is the more sensible or accepted way to do this?

You could adapt.

If the tap times are close enough to each other, then keep a running total and average them.

However, if there is a big gap of a few seconds after the last tap, then clear out the running total and start the average again when new taps begin.

You can also weight the average so the most recent pair of taps affects the average a lot more than older information. This assumes that the human is doing a better job of tapping at the right tempo the longer they continue. At least that's how I am. I start out rough but eventually get in the groove.

If you use a low-pass filter instead of a true average, then this would automatically weight the most recent periods more heavily than older ones.

Any of these ideas should work well unless the user is just randomly tapping or has very bad timing. If they're that bad, I don't think they can complain about whether it's averaged or "most recent."

Brian Willoughby

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