MIDI messaging - motor fader control with Apple Logic Pro X

Hi Guys,

I'm using a Mega 2560 with the MIDI library to interface with Apple Logic Pro X using Mackie Control.

Logic sends out MIDI message E0 XX XX regardless of which fader I move on the screen.

My understanding is it should be E0 XX XX for channel 1, E1 XX XX for channel 2, E2 for channel 3 and so on.

Can anyone advise please?

I can't move the correct fader if I only ever receive E0 XX XX

Thanks in advance.

My understanding is it should be E0 XX XX for channel 1, E1 XX XX for channel 2, E2 for channel 3 and so on.

That is correct.

However unless Logic is set up to send the slider on each channel, which is very unusual, what you see is correct.

However the midi message Ex is the pitch wheel control and not a slider message ( CC ) at all. The two numbers that follow it will be the 14 bit data with a zero in the most significant bit in each byte.

Thanks Mike,

Well, I’ve managed to get access to a Mackie MCU Pro. If I move fader 1 on Logic, fader 1 on the MCU pro moves. Likewise for all the other faders. I’ve monitored the messaging and can only see Ex xx xx messages coming out of Logic when then faders are moved.

Am I missing something obvious? What would be suggested as a good Arduino sketch or program to monitor the messages?

Am I missing something obvious?

Not sure as it is over 15 years since I had Logic on my machine but MIDI message Ex is pitch bend, check it out on:- http://www.midi.org/techspecs/midimessages.php for yourself.

There will be a way of specifying in logic what those sliders map to, you might even have to look in the manual. :)

I've monitored the messaging and can only see Ex xx xx messages coming out of Logic when then faders are moved.

Are you sure you are measuring it correctly? If so it looks like that is how you have it set up in Logic, I assume you didn't set it up but used a pre programmed setup configuration. Is the most significant bit of the two data bytes always zero? They should be. If not something else is getting very mixed up.

What would be suggested as a good Arduino sketch or program to monitor the messages?

Monitoring MIDI on an Arduino is difficult because the Serial port is taken up with gathering the incoming MIDI that then leaves you with nothing to view it on. If you have some form of external display you can use that but you have to have extra hardware. Also if you had a TTL to USB serial lead you could use software serial and send the data back to another terminal.

Hi Mike,

Yes I used a pre-programmed setup.

I have used a program called MIDI Monitor on the Mac to log what was being sent out by the Mac. It doesn't show the data in hex but does show that the relevant channel number when a fader is moved.

Either way I've changed how I detect those messages now. I use the Arduino MIDI library, set a pitchbend handle and the callback function is passed whichever channel the message came from.

Thanks again.

It doesn't show the data in hex but does show that the relevant channel number when a fader is moved.

Go to the MIDI Monitor menu then choose Preferences... Click on the Display tab and you will find you can set the note format, controller format and Data format to hex or decimal.