Variable pulse frequency input - multiplied and divided pulse output. Audio Proj

Hi All,

I could do with some advice please.

I have three analog synths that keep in sync by sending a 5V 15ms pulse to each other along a chain. Turning the tempo knob on the master machine affects those downstream equally.

But I would like to put an Arduino project in there with the sync out of the master as an input to the Arduino. Then two outputs from the Arduino going to the two other synths. One synth is to run at half the speed of the master and the second one running at double the speed of the master.

I've tried various ways of capturing the incoming signal, just in the loop and also as an interrupt (on a RISING signal) and both work fairly well. In both cases, doing the "halving" to the output (just LED for now) also works well. Of note, the output sync signal from the synth is variable and drifts slowly up and down around the target value by around a couple of milliseconds (analog for you).

But I've come unstuck on the "double" side. I'm thinking of using a timer but this is new to me.

Maybe there is a much better way? Eventually I'd like to be able to take an input signal and do various multiples and various divides, e.g. x2, x4, x8, /2, /4, /8 etc. with user input

I have an UNO and breadboard and various components and basic electronics knowledge. The synths have an output pulse frequency of between 60 and 240bpm (beats per minute).

Any advice or even just pointers to relevant reading materials would be gratefully received.




Ok, have found this which I've been finding to be very useful. Now getting a very accurate frequency input, just need to get the outputs working: Gammon Forum : Electronics : Microprocessors : Timers and counters



Ok, cracked it.

Wasn't so hard but not sure I'm using the best method but it works.