VU Meter: ability to set multiple LEDs per track at once.

[sirwesley]

Currently, it appears to be possible to only set 1 LED per VU Meter track.

Maybe it could accept an array of [0...8]?

Example: [0, 8] would light Top & Bottom
Example: [0,1,2,3,4] would light Bottom 5.
Etc.

Note: I'm using the X-Touch Extender as MIDI controller to send to a DMX controller for stage lighting control. So could be fun to have more control over those LEDs in the VU Meter.

[Aldaviva]

Yeah, I really wish we could enable multiple LEDs on the same VU meter at the same time.

Unfortunately, that's not possible on this MIDI device. From the official documentation (PDF page 20, "X-TOUCH EXTENDER MIDI Receive", my emphasis):

Level Meter Receive value 0...127 (bottom/SIG to top/CLIP, only 1 LED on at a time)

The product shots make it look like illuminating multiple VU LEDs possible, but it turns out this only works with non-MIDI protocols like MC (Mackie Control) and HUI (Mackie Human User Interface), which are not how this library communicates with the device and also completely undocumented with no available clients.

There used to be a post on the MusicTribe forums asking this same question, and the answer was basically "it's a protocol-specific capability." Sadly, the forums were deleted a year or two ago and weren't archived.

[toby11]

@Aldaviva do you have a copy of the official documentation - that link above seems to be dead now. X-TOUCH%20EXTENDER_QSG_WW.pdf

[sirwesley]

https://mediadl.musictribe.com/media/sys_master/hd3/h51/8849820287006.pdf try this?

[toby11]

thanks - got it - assume now one has found a way to have all leds lit - I have run the xtouch in reaper in mackie mode and it works that way with displaying more than one led at a time

have you seen this document here where someone seems to have reverse engineered it

http://www.budgetfeatures.com/XctlDOC/Xctl%20Protocol%20for%20X-Touch%20V1.0.pdf

[toby11]

this looks promising

[Aldaviva]

@toby11 thanks for that document, I have not seen that before. It looks like some great reverse engineering work went into that by someone a lot more familiar with MIDI than me.
Also thanks @sirwesley for the working official documentation link. I have checked all the links in the readme and made sure none of them were dead. Also, in case anyone ever wants the originals I linked to above, or if Behringer deletes their website, I saved backup files in Reference Material.

I'll see if I can use that document by FK to get multiple LEDs in one channel's VU meter to illuminate simultaneously by sending MIDI Channel 1 Pressure values. I'm still not sure which of the 4 communication protocols the X-Touch Extender needs to be configured in to receive these inputs; I'm a little worried they're only available in HUI or MC modes, and it seemed like FK was using multiple concurrent connections over different interfaces (USB and MIDI DIN ports simultaneously) for some of this signaling, although that was maybe only required for other features or for tracing the signals. This may work fine in Ctrl and CtrlRel modes (what FK seems to call pure or Xctl) because there is no *1 footnote in the Signal Metering section, but I still don't understand everything in this document and to be honest it's a little confusing.

[Aldaviva]

I tried using the MIDI events in the Xctl Protocol document, but none of the VU Meter LEDs lit up. Here is what I attempted, in case anyone sees a mistake or wants to try themselves.

VuMeter.cs

internal override void WriteStateToDevice(object? sender = null, PropertyChangedEventArgs? args = null) {
    ChannelAftertouchEvent pressureEvent = new() {
        Channel         = (FourBitNumber) 1, // I also tried 0
        AftertouchValue = (SevenBitNumber) (TrackId * 16 + LightPosition.Value) // both TrackId and LightPosition.Value are 0-indexed
    };

    _midiClient.AssertOpen();
    _midiClient.ToDevice?.SendEvent(pressureEvent);
}

I ran this with the AudioMeters sample. I tested with the X-Touch Extender connected over USB in each of the 4 modes: CtrlRel, Ctrl, MC, and HUI.

[toby11]

@Aldaviva thanks from reading that document again I think you may be right that it only works in Xctl mode - I have tested here with your code above and nothing seems to happen. I tested with USB and MIDI din connection.

Going to have a bit more a play with it later though.

[Aldaviva]

Thanks, let us know what you find.

[toby11]

@Aldaviva I have got multiple leds to show - only in HUI mode though

see documentation here

https://forum.cockos.com/showthread.php?t=101328

if you look at this

https://stash.reaper.fm/12336/HUIREFTX.txt

sending the raw midi bytes (over USB) works - i.e. sending these raw bytes resulted in this

controller.SendMidiMessage(0xa0, 0x00, 0x04); controller.SendMidiMessage(0xa0, 0x01, 0x05); controller.SendMidiMessage(0xa0, 0x02, 0x06); controller.SendMidiMessage(0xa0, 0x03, 0x06); controller.SendMidiMessage(0xa0, 0x04, 0x07); controller.SendMidiMessage(0xa0, 0x05, 0x08); controller.SendMidiMessage(0xa0, 0x06, 0x07); controller.SendMidiMessage(0xa0, 0x07, 0x06);

So there is a way to do it but would involve rewriting your library but to use Mackie HUI mode midi messages as all the other midi messages are different as well. I may fork your project and have a go if thats ok - or if your up for a team effort?

[Aldaviva]

Wow impressive! Great work. Feel free to fork this repo and see what you can get working.

On my side, let me start by seeing if I can get anything working with the underlying MIDI library this project uses, and if so I can try to find the time to scaffold out a HUI class and rearrange the class structure to accommodate an additional implementation that integrates with the existing interface, factory, and shares code where possible with the abstract base class.

[toby11]

ok great, I am going to try all the other functionality out for the Mackie HUI messages first to confirm the rest of the faders, encoders, scribble strips etc will work as well.

On another note - on my X Touch full (not the extender one) the scribble strips do not seem to work with your code - but not really checked why yet.

[Aldaviva]

One potential reason for scribble strips not working on the X-Touch might be a different device ID. The SysEx message to set the text and color includes 0x15 at offset 3 (ignore the length comment, that was a coincidence), but the regular X-Touch seems to require 0x14 instead based on MIDI Mode interface specifications. I wonder if there is a way to automatically detect which device is connected, to avoid an extra configuration burden on a user.