Hello,
I’m testing a really simple sketch in arduino that sends a MIDI note on and note off signal to zynthian, it uses the MIDI library by FortySevenEffects (https://github.com/FortySevenEffects/arduino_midi_library).
The circuit is also super simple (only one 220 Ohm resistor involved), and I checked several times that everything is hooked up correctly.
However, I don’t get any sound.
Does anyone have experience with a similar setup?
Thanks!
Have you checked with other devices like a pc or synthesizer…Looks kind of wrong with an s 
If it doesn’t work either, you should tell us more about the Arduino based layout. Or ask the ppl where you found the layout.
Here is what I’ve already checked
My zynthian can pick up notes from the MIDI port from a Yamaha keyboard
When trying other arduino boards it happens as well (no reaction)
at the moment I am directly connecting to the MIDI port with crocodile clips, but I’m sure I’ve connected everything to the right pins
the layout is as described on Notes and Volts here: http://www.notesandvolts.com/2015/03/midi-for-arduino-build-midi-output.html
the Tx pin is connected directly, while the 5V pin has only one 220 Ohm resistor on the way, so not so much space to make mistakes
I’d suggest using a MIDI monitoring program (links below) on your computer to see what your arduino is spitting out. Of course, to run this test, you would also need a USB to MIDI cable to attach the DIN-5 to your computer. A USB to MIDI cable is a very useful thing to have.
http://www.midiox.com/ (Windows) or https://www.snoize.com/MIDIMonitor/ (OS X)
Just for completeness here’s a linux based midi-monitor sketch. If any one has any alternatives please pipe up. . .
> aseqdump&
(The & run it in the background so you get a prompt back),
Will give you . . .
> chris@ellie-Inspiron-N5030:~$ Waiting for data at port 128:0. Press Ctrl+C to end.
> Source Event Ch Data
As it say’s it ‘looking’ at MIDI Alsa Port 128:0 so until something is patched into that it isn’t going to register anything.
So let’s confirm what we have in the Alsa world.
aconnect -lo (list the Alsa outputs)
chris@ellie-Inspiron-N5030:~$ aconnect -lo
client 14: 'Midi Through' [type=kernel]
0 'Midi Through Port-0'
client 128: 'aseqdump' [type=user,pid=9216]
0 'aseqdump '
client 129: 'QmidiNet' [type=user,pid=9227]
0 'port 0 '
1 'port 1
Ooooh look we have two qmidinet ports cos this linux machine is running qmidinet on it, and a sperate remote zynthian is also running with the qmidinet option turned on…
so connect the qmidinet:0 bus to aseqdump . . . .
chris@ellie-Inspiron-N5030:~$ aconnect 129:0 128:0
0:1 Port subscribed 129:0 -> 128:0
And play some notes on the remote zynthian . . .
chris@ellie-Inspiron-N5030:~$ 129:0 Pitch bend 0, value 0
129:0 Note on 0, note 33, velocity 55
129:0 Note off 0, note 33, velocity 52
129:0 Pitch bend 0, value 0
129:0 Note on 0, note 33, velocity 71
129:0 Note off 0, note 33, velocity 108
This has been:
I’ll go back to water pumps. . . .
Thanks to everyone for the suggestions, in the end I’ve found what was the problem.
In the next days I’ll hopefully be able to show what I was working on 
It could be helpful to mention the solution in case someone else has the same problem later!
Yes, we deserve a little gore… 
Pictures are almost mandatory . . .
Apparently it’s all to do with something called the Instanet. . . . . 
I’m a complete noob, so the mistake was quite stupid. I got confused with the wiring of the midi port, because in some diagrams it is depicted from one side and in other diagrams from the other, and I interpreted it wrong, so the pins 4 and 5 were inverted.
That’s learning! It’s not stupid. It’s insight.
I learned so much when I soldered a CA3130 in a Sample & Hold Circuit the wrong way round ( It cost about half the money I earned in a week ).
It was so hot it burnt the lettering backwards into my young finger, BUT it did survive when I put it in the right way round.
That was stupid !!