Akai APC Mini Led Output not working properly

[Maikel Boerebach]

I am having a problem with my new Akai APC Mini.
I have used a Novation Launchpad in the past to control QLC via MIDI, and the Feedback of the LEDs worked as expected. When I pushed a button, the LED would turn on and when i hit it again the LED turned off. The APC Mini however does not seem to work that way. When i hit a button, the LED will turn on, but it will not turn off again. This is really annoying, since the LEDs have no use, when they are all continuously lit. Does anyone have a similar problem? If so, does anyone have a workaround for this?

[Maikel Boerebach]

I attached the Screenshot, which apparently states, that the button both sends an note on and note off value. I am guessing since QLC only sends back the first incoming note value the light stays lit. Is it possible to send a note off value?

[Maikel Boerebach]

I managed to come close to the problem. Apparently the APC Mini which sends notes, needs a velocity larger than 0 to trigger the LED output. Since QLC sends a 0 as an output, the LED wont reset and therefore stays continuously lit. Can anyone tell me how to change the code to change this?

[Jano Svitok]

Hi,

https://github.com/mcallegari/qlcplus/b ... l.cpp#L147 is the line that sets velocity (data2) to 0 (value).

I can see to quick solutions:

1. change line 147 to

*data2 = DMX2MIDI((value == 0) ? 255 : value);

2. remove lines 140-142, so MIDI_NOTE_ON is always used.

Either of them may or may not work. I suppose that there is some more magic involved, since the LEDs are 3-color.

Good luck and please let us know your results!

[Maikel Boerebach]

Thank you so much for your response. I will try to compile it as soon as possible, and will come back to you with my (hopefull) progress.

[Maikel Boerebach]

Since this was my first try compiling qlc, i expected to stumble on the environment itself.
I keep getting this error message from xcode while compiling. I am guessing it has something to do with the way i installed OLA. I tried both the original qlc, as well as the revised version, but the error stays the same.
Undefined symbols for architecture x86_64:
"ola::StringTrim(std::string*)", referenced from:
ola::QLCLogDestination::Write(ola::log_level, std::string const&) in qlclogdestination.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [libolaio.dylib] Error 1
make[1]: *** [sub-ola-make_default] Error 2
make: *** [sub-plugins-make_default-ordered] Error 2
jonass-mbp:qlcplus jonas$

I am using a macbook pro x64 with xcode to compile the software.

[Legi008]

Hi, sorry to use your post but i have 2 questions about the Akai APC Mini.

Is it possible to assign a custom sound to each key ? (like a laugh or a quote)
The sound the Akai makes come out of the PC ? or is there a mini jack (headset) out ?

Thank You

[Joep Admiraal]

It could be that the reason why the led's are not working as expected is the fact that we did not yet create a midi template for it. QLC+ works correct with the APC20/40 in Ableton mode2. To set the device in that specific mode, a midi sysex message has to be send at when QLC+ starts. This message is unique for each type of APC device. So far I only know the sysex message for the APC20 and APC40.
Also I could not find any documentations on the midi messages of the new APC devices.
Could you start Ableton and record the sysex message it is sending to your device?
I can then create the correct midi template for QLC+

Regards,
Joep

[Maikel Boerebach]

I used MidiMonitor to find the Sysex message(s). I attached the file.
The Log states: To APC Mini: 00 F0 7E 7F 06 01 F7
From APC:00 F0 7E 7F 06 02 47 28 00 19 01 00 00 00 7F 00 00 10 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 20 00 00 F7
Cheers,
Maikel

[Joep Admiraal]

Thanks for the MidiMonitor file. I think this is the message we're looking for:
F0 47 7F 28 60 00 04 41 09 01 04 F7

I created an updated midi template for it and attached it to this post.
You have to place this file in the correct folder (~/Library/Application Support/QLC+/MidiTemplates on a mac).
When this is done, you can select the APC mini init message in the Configure Midi Plugin screen.

[Maikel Boerebach]

Hi Joep, first of all thanks for the help. I have transferred the *.qxm-file to the appropriate folder and qlc does seem to send the sysex-message to the apc.(see attached file). Unfortunately, it does not seem to have an effect on the Led behaviour. I also attached the Ableton live midi output, and it seems to me that the apc sort of communicates with live. Ableton sends a 6-bit string sysex to the apc and the apc responds with a 35 bit string sysex. Then ableton sends out the 12-bit sysex that you implemented in the *.qxm-file. I tried using both strings, but i cannot seem to get qlc to send the two strings. Any suggestions?

[Maikel Boerebach]

Somehow my browser crashes when I try to upload multiple attachments, so here is the midi-monitor file containing the ableton startup-sequence.

[Joep Admiraal]

The first two messages are the Device Enquiry messages. They should not alter the state of APC.
See the communication protocol document for more info about the APC protocol:
http://www.akaipro.com/product/apc40#downloads

[Joep Admiraal]

As for the compilation issue, I am no expert but here are some tips.
I am also using MacOS.
Did you follow this HOWTO?
https://github.com/mcallegari/qlcplus/w ... uild-HOWTO

I tend to have some compilation issues with some of the plugins and just disable them when I am compiling for myself.
Since you seem to have problems with OLA, you can try to disable it by adding a # in the plugins/plugins.pro file in the beginning of the ola line.

[Maikel Boerebach]

I have disabled it as you guys suggested, but now I'm struck with another error... I have tried reinstalling the necessary tools about ten times now an I cannot find a way to fix this. I am currently compiling on OSX 10.9.5.. I attached the error code, and I have no idea where to follow back on it..





d hid/ && /Applications/Xcode.app/Contents/Developer/usr/bin/make -f Makefile
g++ -c -pipe -Werror -g -gdwarf-2 -arch x86_64 -Xarch_x86_64 -mmacosx-version-min=10.5 -Wall -W -fPIC -DQT_PLUGIN -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/local/Qt4.8/mkspecs/macx-g++ -I. -I/Library/Frameworks/QtCore.framework/Versions/4/Headers -I/usr/include/QtCore -I/Library/Frameworks/QtGui.framework/Versions/4/Headers -I/usr/include/QtGui -I/usr/include -I../interfaces -I. -I. -F/Library/Frameworks -o hidfx5device.o hidfx5device.cpp
hidfx5device.cpp:189:26: error: expression which evaluates to zero treated as a
null pointer constant of type 'const char *'
[-Werror,-Wnon-literal-null-conversion]
chunk.append((char)0x0, 32 - chunk.size());
^~~~~~~~~

[Jano Svitok]

Hi,

this seems like a genuine bug. Please try to replace line 189 in plugins/hid/hidfx5device.cpp:

chunk.append((char)0x0, 32 - chunk.size());

with

chunk.append(QByteArray(32 - chunk.size(), 0));

[david garyga]

Hi,

I don't even get how this line can work ?
There is no prototype of QByteArray::append(char ch, int size)
It could call QByteArray::append(QByteArray const& other)
by creating a QByteArray on the fly, but even then, the prototype for creating a QByteArray is QByteArray(int size, char ch)

CF:
http://qt-project.org/doc/qt-4.8/qbytearray.html

I think here, when the compiler is happy, we actually append an empty byte array. (QByteArray(int size, char ch) is called with size = 0 and ch = 32 - chunk.size())

Try replacing the line from:
chunk.append((char)0x0, 32 - chunk.size());
to :
chunk.append(QByteArray(32 - chunk.size(), (char)0x0));

[Jano Svitok]

Most probably this was being called (http://qt-project.org/doc/qt-4.8/qbytea ... l#append-4):

QByteArray & QByteArray::append ( const char * str, int len )

thus compiler complained that pointer str is null.

[Jano Svitok]

David, I've pushed your solution to git. Maikel, try to pull from git.

[david garyga]

Yes, you are right !

Result is the same, nothing is appended at the end of the buffer.