Tap Tempo circuit

[StephenGiles]

Is this any help?
http://www.circuitcellar.com/AVR2004/wabstracts/A3721abstract.pdf

[The Tone God]

I have done tap tempos. The trick is really manging the timer(s) to make sure you get the right time from the input to the output. Things can be made even tougher depending on the type of output you need.

If you want an example of tight time control wait a few days.

Andrew