IntervalTimer for very short intervals?

[syso]

For a MIDI sequencer application, I wanted to use the Interval Timer to generate the "Clock".

This is the code:
https://gist.github.com/DatanoiseTV/10683910d877e187037515ff2e98cab6

Now with the upper main.ino, it doesn't work. If I set the interval to 60000 / BPM (e.g. 120) it works.
The formula is 60000 / (BPM * PPQ) (milliseconds).

My guess is, that my interval is too short?

 

[Frank B]

For a MIDI sequencer application, I wanted to use the Interval Timer to generate the "Clock".

This is the code:
https://gist.github.com/DatanoiseTV/10683910d877e187037515ff2e98cab6

Now with the upper main.ino, it doesn't work. If I set the interval to 60000 / BPM (e.g. 120) it works.
The formula is 60000 / (BPM * PPQ) (milliseconds).

My guess is, that my interval is too short?

What is the shortest interval ?

 

[syso]

What is the shortest interval ?

In this case with BPM = 120 and PPQM = 24: 20 and it doesn't work.
In worst case BPM can be 240 and PPQM = 384.

Edit: I figured out the interval is in microseconds. One moment.
Will try with internalClock.begin(isr_outer, (60000000 / (bpm/ppqn)) );

Works! Thanks Frank