USB MIDI example (IDFGH-6921)

Is your feature request related to a problem? Please describe.

I have been struggling to get esp32s2 to receive midi data over USB. There are Arduino libraries that can do this, but I want to use esp-idf :)

Describe the solution you'd like

I would love to have a midi usb device example to study.

Describe alternatives you've considered

I have tried to port the Arduino examples to esp-idf but it is too complicated, the API is very confusing.

Additional context

I think a working example for midi usb device would add a lot of value to many users. There is a growing demand to use esp32 variants as audio and midi devices, and adding an example for usb midi would really be appealing to many users! ESP32-Arduino is a fine solution for some such users, the Adafruit TinyUSB port works in that environment, but many people prefer the more powerful esp-idf, but a working midi usb example is missing!

[chegewara]

https://github.com/hathach/tinyusb/tree/master/examples/device/midi_test

@chegewara I definitely looked at this example, but it is not ported to esp32. Would you expect this to compile and run if I just copy it into my program? There are so many defines and unusual import patterns that I am unable to really see how these things work.

for example #include "bsp/board.h" seems doomed to fail.

@chegewara you have done a lot of work on USB on ESP32, including a midi usb driver for Arduino. Would you be willing to share a bare-bones working example of usb midi device for esp-idf? Just getting access to midi data, via usb on esp32s2, and printing it to the console (not parsing or anything) would be so very helpful, and I imagine MANY users would be overjoyed to have access to this feature.

[chegewara]

All arduino libraries ported to work on esp32 S2, which are my library, espressif and adafruit, are based on that tinyusb.
Adafruit and my library is also supporting MIDI, so it is possible to do it with esp-idf too.
If you have problems with something which does not look like USB code, just like bsp/board.h, then remove it from code (this header is to use LEDs and buttons).
Currently i am working on full time with esp32 and rest of my time i am just resting (i am lazy). In other hand there are few skilled, having knowledge about USB and helpful people at espressif, so i believe they may help you.

@chegewara Yes I noticed all the Arduino USB libraries work from tinyUSB, I have looked at them all, but I find it too complicated, and under documented, to replicate. I have a feeling that there are some functions and macros that make the existing esp-idf HID examples deceptively simple looking, but those same helpers do not exist for MIDI.
It's by far the most complex and confusing protocol I've attempted to work with. A working sdk example file is so vital in moments like this, and I agree with your feeling that surely someone at Espressif would be able to make such an example quite easily. Is there anyone that comes to mind that you would be willing to tag in this issue?

[spacenate]

@ultrapalace take a look here: https://github.com/touchgadget/esp32-usb-host-demos/blob/main/examples/usbhmidi/usbhmidi.ino

I tried to run this on ESP32-S2, and had some trouble: the midi_transfer_cb() was not being called (though I was not running that example code directly, but using it as a reference for my own implementation. Perhaps the issue is with my own code, which I will get back to debugging soon). Good luck.

thanks @spacenate but I am looking for USB device, not host, and looking for esp-idf not Arduino :)

[adokitkat]

thanks @spacenate but I am looking for USB device, not host, and looking for esp-idf not Arduino :)

I will take a look at it. For now here's a git patch file containing a fixes to ESP-IDF's TinyUSB wrapper and a ported MIDI example.
TinyUSB-MIDI.zip

You can apply the patch to IDF's master branch and try it out. The example will appear in examples/peripherals/usb/device/tusb_midi.

I've tested it on ESP32-S2.

I've tested it on ESP32-S2.

I have tested it as well and the examples works :)
Thank you so so so much @adokitkat ! I appreciate you!

Is it likely this will make its way into master at some point?
Is there any way I can contribute? Testing / example code / docs / etc. Just let me know <3