Arduino for STM32

You should never try to do "real work" inside an ISR. You should do the absolute minimum possible such as set a global flag (usually marked 'volatile') then get out immediately. You should certainly never try to call anything else that uses or requires interrupts. If you do then, well...you ...

ag123 wrote: Wed Jul 08, 2020 10:31 pm my guess if you are simply using serial, the default usb-serial 'driver' may work better,
on stm32f401 with the usb-serial CDC (vcp) 'driver'

I am using USB midi, just using serial for debug.

upon closer investigation it seems I can send some data as long as it's only one packet?

this works:
CompositeSerial.print("I can send a lot of data as long as it is all sent as one packet like this.");

this fails:
CompositeSerial.print("two");
CompositeSerial.print("lines");

this also fails ...

I am making a guitar pedal synchronizing thingamajig and as part of that i want to receive clock pulses from analog sequencers and output a MIDI clock via USB and serial. To get the timing accurate enough I have attached an interrupt to a pin monitoring the clock pulses coming in.
Ideally I would ...

What is LSCS ?

Why does the blue pill have 2 crystals?

Would like to see tid happen, can help with testing if necessary

Thanks fredbox! that works like a charm, i was not familiar with the systick interrupts and it took me a minute to realize that STM core was different from Roger Clarks "Arduino STM32" but adding "systick_attach_callback(&encoder1_read);" in setup made it run perfectly on my blue pill running Roger ...

Any idea where I might find what modifications to make?

Edit: didn't see the above post before posting this

update:

It seems the problem is with attaching an interrupt with the argument "CHANGE" :

attachInterrupt(digitalPinToInterrupt(PIN_A), encoderISR, CHANGE); //call encoderISR() every high->low or low->high changes

the interrupt seems to only trigger on rising edge, I managed to get the encoder ...