Explain about the PCB

[rahmatismail]

Could you help to explain the PCB. I'm new into STM32, probably I can support this open source project if I understand it a little bit.

• Which code that communicate with the LCD? I opened my meloaudio but could not figure it out. Is it like a i2c connector or something? So many pin that I'm not sure whether they are all used.
• Which code that communicate with the switches?
• Which code that communicate with the I/O (midi, usb, expression, etc)?

It would be great if could share the PCB schematic for this board.

[harvie256]

@rahmatismail

There is no schematic for the PCB, I just reversed engineered the pins that were needed to do what I did. All the pin outs were directly defined in the project, if you're after that check out the main.h file definition. https://github.com/harvie256/midi-commander-custom/blob/main/MIDI_Commander_Custom/Core/Inc/main.h

All the other information I gathered from tracing the PCB is in https://github.com/harvie256/midi-commander-custom/blob/main/HardwareNotes.txt

The low level switch code is in https://github.com/harvie256/midi-commander-custom/blob/main/MIDI_Commander_Custom/Core/Src/switch_router.c

Granted the switch scanning is not that intuitive as I'm passing around an array of pointers, but it makes the whole code a lot faster.

And the I2C display makes use of a 3rd party library, so it's a pretty small file:
https://github.com/harvie256/midi-commander-custom/blob/main/MIDI_Commander_Custom/Core/Src/display.c

The majority of the code files are auto generated or included by STM32CubeIDE. You need to be opening the project in that IDE as the layout follows their template.