Din In always on

I have designed a custom MIDI controller that sends and receives MIDI.
When I connect my DIN Out to my Bome Box DIN In, the LED light up solid, even if I’m sending no MIDI at all, and the MIDI messages don’t seem to be received.

If I connect my controller to my soundcard’s DIN In, everything works as expected, and if I connect another commercial controller to the BomeBox DIN In it also works fine.
So it’s really only when connectin MY controller to the BomeBox that I have this behavior.

Voltages seem to be in line with the MIDI electrical specs.

Never mind, I found what the problem is : my TX voltage was 3.3V, and the ref voltage 5V.
Although this works fine on my soundcard, it seems the BomeBox is more sensitive.

Yes, I believe that you may need to either adjust the Vss voltage of your output device or add an in-line resister from your output voltage to insure it meets the proper current specification.

Steve Caldwell
Bome Customer Care

Also available for paid consulting services: bome@sniz.biz

Just a quick clarification, the BomeBox is built using the updated MIDI-DIN specification, which works with 5V and 3.3V devices. But if a device does not comply 100% with the MIDI-DIN electrical specification, the BomeBox may or may not work with it, and other MIDI devices also may or may not work with it…

So it’s good that you found the problem and can fix it! Thanks for reporting.

Yes, I didn’t know about this specification, thanks for your help Florian.
Now I have a fully compliant device.