(Akai APC mini) Update LED

Tags: #<Tag:0x00007f6af16b8f60>


I use Cantabile with my APCmini and I have programmed the LEDs to react to certain actions, but, certain LEDs are used for 2 actions, I would like to know if, for example, the SHIFT key (Note 92 it seems to me) can used to update the LEDs

Basically, I press it, and it reapplies the state of the LEDs according to the fader

Thanks Google Trad (I’m french)
Thanks you :wink:


I also use an APC Mini to load songs, and I’ve messed with trying to program the LEDs, but near as I can tell those only respond to SysEx messages which I haven’t been able to suss out.

Is this true, and would you be willing to share how you are triggering the LEDs?


Voici ma configuration || This is my settings :slight_smile:
Only on PERFORMER version of Cantabile


Huh - so you’re actually triggering them with Midi note values? Alright, I need to do some more testing with mine, because I couldn’t get that to work - I must have done something wrong.


Alright, I did some more digging. I found this image where someone has worked out some of the SysEx for the APC mini:

Source forum here

So, sending the SysEx “90 00 01” will turn the leftmost bottom button green, just as if you send Midi note 00.

But, strangely, it seems like sending the SysEx commands once doesn’t always work. So, I set up my commands where, instead of triggering SysEx, they target “Triggers” - and I then make a Trigger to send the SysEx, and then make a copy of that binding.

Seems to work so far, still testing


Just to clarify: There is no SysEx “90 00 01” - this is just the hexadecimal representation of “Note On”, “Channel 1”, “Note 0”, “Velocity 1”. The pictures you shared show simple note commands - just in hex notation…

SysEx commands start with hex F0 and end with hex F7.

So instead of fiddling with Sysex, you can simply use NoteOn messages.




Interesting - because after fidgeting some more, I’ve found that the first pair is unnecessary, and the APC will respond to 00 01 just as well as 90 00 01. However, the last pair determines the LEDs color. So 00 01 will turn a light green, but 00 03 will turn it red.


Hi all, I also worked with an Apc mini with cantabile. Velocity is triggering led color. Here is the complete midi implementation I found to program it. But I used Bome Midi Translator inbetween cantabile and the Apc to manage the leds, which was simpler for my purpose.

Salut, j’ai aussi utilisé l’Apc mini. C’est la vélocité qui declanche le changement de couleur. J’avais trouvé cette implémentation midi complète sur le net.
Mais j’ai utilisé Bome Midi Translator entre Cantabile et l’Apc pour gérer tout ce qui était Led, c’était plus simple pour ce que j’avais à faire.


Careful with that - this is called “running status” in MIDI - it is a tricky mechanism to reduce the amount of data sent over a (slow) MIDI connection. It works like this: after you have sent one “command byte” (in your case 0x90), any following data will be treated as if the same command had been sent before. So your message of 00 01 will be treated like 90 00 01. But - and that’s the risk here - once any other command (like e.g. Control Change) is sent, your data (00 01) will be treated as control change data and not like note data. And if (after turning on your device) you send these bytes without a command byte before them, your device will not be able to interpret them.

See here: http://midi.teragonaudio.com/tech/midispec/run.htm

I would definitely advise NOT to use this scheme - it is highy error-prone; you should only use that if you reeeeally know what you are doing and are truly knowlegeable around the MIDI specification…

Simplest and safest way to work with your APC mini is just to send Note On commands using the respective Cantabile bindings - better stay away from the fiddly stuff if you don’t really need to use it…




On my settings, only “NOTE” is use.
The problem is that the state of the LEDs is sent only once, I would like to have a button (the SHIFT button) to re-send the state of the LEDs


What is it that determines the color of the LEDs that you want to re-send? Is it the faders (bottom of your screenshot)?

The issue you’ll have to deal with is that for any binding, Cantabile only sends a message when the source changes - there is currently no way to force Cantabile to re-send the value for any binding.

What I would do in your specific situation is create an individual script for ReaJS that

  • listens to incoming fader messages
  • locally “remembers” these fader messages
  • sends out the right note message for your fader messages as they come
  • listens for a specific “trigger” message (coming from your SHIFT key) and then sends out the notes for “remembered” fader messages again

Not a big job to build something like this if you have some programming skills and know your way around JSFX code.




Unfortunately, I have no programming skills, forget the faders, but is it possible to re-send the media player status signal at this time.

my goal would be to vary the colors of the PAD depending on the state of the fader, but once the fader adjust, to return to the state of the Media Player on the PAD

Thaks :slight_smile:


Unfortunately, the same applies - Cantabile only triggers bindings when their source changes, i.e. when the status of the media player changes.

Best to keep the pad colors “single-purpose”; then they’ll reflect the Cantabile source reliably. If you use them for multiple purposes, there’s currently no way around some custom programming…


Ho, ok, a update later :smiley:

Thanks all :wink: