Could be. If data in and out were switched nothing would happen in both cases.

Btw, pictures help more than a thousand words.:)

maybe you hooked up the arduinoboy output to gameboy link cable wrong

What exactly are you trying to do? Are you trying to play notes, or just start the song, or what? I have a ton of problems when trying to sync my MicroKorg and Korg MS2000 to LSDJ. When the AB is in LSDJ Slave mode, the only things I can do with the Korgs are start the song (can't remember which key does that) and change the tempo. It's very glitchy tho, and I've heard a lot of other people complaining about using Korgs with ABs. Try syncing your AB to your computer, it's much easier to troubleshoot that way in my opinion. You can also test the MIDI In by using your Electribe to play notes through mGB. Then you can test the MIDI Out by syncing LSDJ (Master) to your Electribe's MIDI In, then start a song in LSDJ and see if the tempo LED on your Electribe syncs with the status LED on your AB, but I believe that's all you will get from the Electribe unless using the special MIDI OUT version of LSDJ.

that doesn't do anything, the electribe plays but no LED's light up and LSDJ still says wait, same with LSDJ as the master the korg won't start playing and LSDJ plays but no LED's light up. Does the fact that I'm using an arduino micro make any difference, like to the pins change at all?

plug the midi cable from the arduinoboy to the electribe's midi out. set lsdj sync to MIDI mode and then hit start on the song screen. it should say WAIT on the side. then hit start on your electribe.

So I just built my first arduinoboy and it works, the LED's light up like they ought to and I can change modes and all that HOWEVER when trying to sync LSDJ to my korg electribe MX nothing happened. I'm not sure if there are settings I need to change on the korg or LSDJ (I set LSDJ sync to slave and master but is there anything else?). The status LED does not light up when I have the korg plugged into the midi in or when LSDJ is in master mode. I switched the two wires that connect the midi in jack because I did have them wrong initially but still nothing. Any help would be greatly appreciated

edit: I just realized I posted this in the wrong forum, sorry about that