I've modified the Arduinoboy code to enable on-the-fly switching of MIDI out channel.
Use LSDJ command X6y (y=0-F => MIDI ch 1-16).


- Play command X64 in PU1 => now PU1 sends MIDI out on channel 5.
- X60 changes back to MIDI channel 1.
- The change is instant which means it is possible to use 16 different sounds on your MIDI gear (though only 4 at the same time).
- Go make some cool tracks!

BUG: only works in PU1. I haven't been able to find out why it doesn't work for PU2/WAV/NOI. If anyone has any ideas, please help!

Code is here, upload it to your Arduinoboy the regular way:

Last edited by Ledfyr (May 10, 2016 6:51 pm)


Great work! I'm going to cherry pick this commit into my own fork. It would be nice if we could work out who's repo will be master. It doesn't seem like trash80 wants to maintain it.


This is awesome. Thanks!


I have fixed a bug! Now the channel switching works in all GB channels. Previously it only worked in PU1.

If anyone tries this, let me know if you find other problems.

Madriz, Supain

im gonna try it right now. Im not even sure I know how to use the files from github, but whatev smile

Madriz, Supain

Now my arduino isnt working at all. While i admit i was nervous about the whole flashing the arduino part, i just downloaded the github and flashed it onto my unit. But now when i hit start, nothing happens. Im trying the change channel commands but no luck as well.

I guess this is no place fro troubleshooting but im having 0 luck


It works on my end, however still only in PU1 (I was so sure I had found the bug! I'll test it before I upload next time).

Do you see the LEDs flashing like they should?

Do like this (maybe you already did):

- Download code as .zip from GitHub and unzip
- Connect Arduinoboy to USB port on computer
- Open code in Arduino IDE
- Set correct port for your Arduinoboy
- Compile by clicking the (V) icon
- Upload to Arduinoboy by clicking the (->) icon
- Disconnect Arduinoboy from computer and connect it to another USB power source (may not be necessary).
- Set MIDI out mode on Arduinoboy
- Start GB, set MIDI out mode in LSDJ.
- Connect Arduinoboy to GB Link port.
- Should now work. Otherwise, try trash80's original code.

Madriz, Supain

I tried that, máster on lsdj, midi on lsdj, arduino in all modes. Maybe Im doing something wrong with my other midi device sad


If the LEDs blink as usual, I think that the Arduinoboy works.
If not, something might have gone wrong when uploading the software.

Regarding the bug ... sad
I can't figure out why channel switching doesn't work in PU2/WAV/NOI, but I guess channel switching in PU1 is better than nothing.
If anyone can spot the error please let me know.

Last edited by Ledfyr (May 10, 2016 6:58 pm)