Does not handle Running Status about midi2usb HOT 4 CLOSED

Hello.
You are right. This firmware do not handle Real-time control and SysEx events. My keayboard does not support these messages. I cannot test it and I thought it was not important. Now I will change my mind.
I have found Table 4-2 in MIDI 1.0 spec with Examples of parsed events (page 17). It would be great if you show your 0xF8-command handler.

from midi2usb.

This looks promising for a method of providing test scenarios in absence of gear:
https://github.com/jazz-soft/test-midi-files

from midi2usb.

Sorry, I do not understand how to test USB device with MIDI files.

from midi2usb.

I am no longer actively using your library for a project, thus have not tested further. In my above suggestion, midi files have a set format - the list of files have a variety of known message formats. I would suggest you get / create a small device to use as your test where you parse the files and push in/out MIDI din to your hardware device, testing your device handling. There are a lot of example Raspberry Pi / Pico code out there to take the MiDI files and interact with DIN.

from midi2usb.