Is your optocoupler IC in backwards?
EDIT: Yeah, it looks like it is. The stripe on the IC indicates the side with pin 1. Pull the IC out and rotate it 180 degrees.
hmm alright I'll try that. but it has a stripe at one of the ends of it and it matches up with the printed marking on the pcb.
Edit: SOrry I confused the components, I'll try and update!
EDIT2: Thank you!!! That was the issue!
It's beyond me how I managed to mess that up though, cause I was sitting and carefully pairing up the components in the right direction/order before soldering!
You can also test midi input with keyboard mode in LSDj (Using channel 16 and keyboard mode from arduinoboy) check the note values from arduinoboy repo.
If that fails I can upload you serial print gb rom that can print what gameboy receives (Unless you have GBDK installed and can build the rom yourself)
Thank you very much for your help!
Last edited by ScanianWolf (Nov 24, 2020 8:50 pm)