Is there a way to change the midi baud rate?

midi
#1

hey in my quest to sync two axo's oscillators i realized some issues with the midi gate bools beeing inconsistent in timing, probably due to both midi being at 31250 baud and then the bool just being processed at k-rate 3khz ish. correct me if this is nonsense.

i'm not sure if it will actually help me in my endeavour, but is there an easy way to access high speed midi on the axoloti? would it only work over usb-midi or also the din ports?
i am building the midi controller i want to connect myself, so it would be easy to set the serial baud rate to the same on both sides, ie 48khz or even higher. apparently people did this already on arduinos https://forum.arduino.cc/index.php?topic=515491.0

can i do it with the built in din ports? or alternatively open a serial connection, add a simple DIN-IO circuit to the TX/RX pins, and read/write to it with ie. hug/gpio/midi_out ? cause on my "own" serial connection i can do whatever baud rate i want right, as oppsed to midi DIN?

#2

ok i think usually i am not the person who talks first and then thinks, even if my entry on this board might make it seem like that.

i think it's a k-rate/cycle sync issue, not a midi issue after all.

my test setup is this: i have two axolotis running the same simple patch with a square oscillator and a s-rate VCA. OSC is reset and VCA is triggered on a midi note gate signal. both are being fed the same midi input. while i was not expecting both osc's to be in sync because the clock cycles will be offset and not synced, i did expect the offset to be consistent.

but hitting random midi notes, every now and then i get a different (constant) amp offset bewtween both axo's. this is probably due to those notes falling into a moment where one axo is already on the "next" k-rate cycle. which would also explain that the offset difference between both options constantly is around 1/3ms.

Screen Shot 2019-04-06 at 7.05.59 PM.png697x340 31.1 KB

1. AXO 1 "normal" as in more likely
2. AXO 2 "normal" as in more likely
3. AXO 1 with extra offset
4. AXO 2 with extra offset

so yeah. am i drawing the right conclusions? how do i get high speed / custom baud midi input, and pass it to my OSC/VCA reset inlet in s-rate?

edit: from what i can tell both the VCA trigger and the OSC reset are offset by the same amount. so that part is in sync at least haha.

#3

I am not sure it will work, cause i have not tried it myself, but in theory for making the midi code process at sample rate, 48khz:

If you are using the Axoloti editor, you could move your code to the s-rate fan, then it will be processed at 48khz:

Not sure i it will work, but you can try it out :slight_smile:

#4

Yeah thanks i am currently trying out what code and connections make sense/are possible in s-rate.

iirc the bool connections, ie. the midi note gate out is per definition in k-rate though right? so i'd probably have to edit that one to start with, to have it update the outlet with the incoming midi data more often.

#5

Sorry, that I don't know. Maybe we can ask @thetechnobear....... :slight_smile: