[PD] communication between pd-instances & midi synchronisation

[Jakob Laue]

Hi dear list,

I have an eight-track-sample-player patch running on a raspberry pi. The sample player patch contains a metronome. This metronome does two things:

1) It acts as the instance that the eight sample tracks are synced to, in order to have the wav-files playing nicely in sync.
2) It sends out midi-clock data to an external hardware looper (856 for zellersasn) to keep it in sync as well.


I am recording/looping audio coming out of the sample-player-patch with the hardware looper. All the syncronisation stuff works, but of course I have an unacceptable latency between the audio of the patch and the recorded audio on the looper. According to this thread..

https://forum.pdpatchrepo.info/topic/4584/midi-latency-in-pd

..I think about splitting my metronome and my sample-playing into two instances of pd. One instance should contain the metronome with audio latency (=midi latency?!) set to a minimum and the other instance should contain the sample-playing-part. This way, the metronome-instance could send midi-clock to the looper with low latency. But it also has to send a clock signal to the other instance of pd, so that my eight samples keep on playing in sync. What would be the best way to send this latter clock signal from the "midi"-instance to the "audio"-instance of pd? Maybe osc? Or is there even a special [send] to share data between different instances of pd?

Btw: I cannot set the audio latency in the "audio"-instance lower than 25 msec, otherwise the audio starts popping and clicking.

Thanks and all the best,
Jakob