VU-Meter LEDs for Hercules DJControl Jogvision in DJay Pro

DJ Hardware
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Working VU-Meter LEDs for Hercules DJControl Jogvision in djay Pro (custom .djayMidiMapping)

Since the Jogvision was never officially supported by djay, its VU-meter LEDs have been a known dead end in the community for years (see the old threads: “MIDI Mapping VU-meters and LED feedback in general” and “Djay Pro with Hercules JogVision”). I finally got them working on both decks using a custom .djayMidiMapping file, and wanted to document the fix since it wasn’t written down anywhere.

TL;DR

Add this to the <key>outputs</key> array of your .djayMidiMapping file:

<dict>
    <key>controlType</key>
    <string>control</string>
    <key>keyPath</key>
    <string>turntable1.monoMeter</string>
    <key>midiChannel</key>
    <integer>0</integer>
    <key>midiData</key>
    <integer>68</integer>
    <key>midiMessageType</key>
    <integer>1</integer>
    <key>midiMinValue</key>
    <real>0</real>
    <key>midiMaxValue</key>
    <real>6</real>
</dict>
<dict>
    <key>controlType</key>
    <string>control</string>
    <key>keyPath</key>
    <string>turntable2.monoMeter</string>
    <key>midiChannel</key>
    <integer>1</integer>
    <key>midiData</key>
    <integer>68</integer>
    <key>midiMessageType</key>
    <integer>1</integer>
    <key>midiMinValue</key>
    <real>0</real>
    <key>midiMaxValue</key>
    <real>6</real>
</dict>

Why this works

The Jogvision’s VU-meter LED protocol is officially documented by Hercules (buried in a PDF most people never find, linked from the Jogvision support page under “MIDI mapping” → “Midi Commands DJControl jogvision”):

VMETER_LEVEL_DA   90 44   Note On, Deck A, note 0x44 (68)
                          value 00 = all off
                          value 01–06 = lights LEDs 1 through that number
                          value 06 = all 6 LEDs on

VMETER_LEVEL_DB   91 44   same, Deck B (channel 2)

So it’s a single Note message per deck; the velocity (0–6) directly sets how many of the 6 segments are lit. It is not a 0–127 range like most CC-based meters — that was the mistake that cost me the most time.

The keyPath (turntable1.monoMeter / turntable2.monoMeter) isn’t documented by Algoriddim anywhere either, but it’s confirmed to exist and work by pulling the outputs block straight out of djay’s own natively-bundled mappings for other controllers that do have officially supported VU-meters — e.g. Hercules DJControl Inpulse 300.djayMidiMapping and NI Traktor Kontrol Z1.djayMidiMapping (both ship inside djay Pro.app/Contents/Resources/MIDI Mappings/). Both use the exact same keyPath, just different midiData/midiChannel matching their own hardware’s protocol.

How to apply it

  1. Quit djay Pro.

  2. Open your Jogvision .djayMidiMapping file in a text editor (it’s plist/XML). On Mac it typically lives in ~/Music/djay Pro/MIDI Mappings/.

  3. Paste the two <dict> blocks above into the <array> under <key>outputs</key> (create that key/array if your file doesn’t have one yet).

  4. Save, relaunch djay Pro, load a track and play.

What I couldn’t get working: the 4 beat-position LEDs

The Jogvision also has 4 LEDs that mark which beat (1–4) of the bar is currently playing (BEAT1_DA–BEAT4_DA, Note On/Off, notes 0x3A–0x3D — also documented in the same Hercules PDF). Unlike the VU-meter, this one’s a dead end via custom mapping: djay ships a hardcoded, private class called HerculesBeatAssistLEDController (visible via strings on the app binary) that appears to drive beat LEDs directly for natively-recognized Hercules controllers, bypassing the generic outputs/keyPath system entirely. There’s no exposed keyPath that reflects “current beat position in bar” that a custom mapping can bind to — I checked every native mapping file that has any kind of beat-related output, and none of them expose it this way (Pioneer/Denon/AlphaTheta gear all use per-device-family solutions like customProcessor.* or CDJ HID protocols, not something transferable to a generic MIDI output).

If anyone from Algoriddim reads this: exposing whatever drives HerculesBeatAssistLEDController (or a generic turntableN.beatPositionInBar-style keyPath) as a normal output-bindable property would make this fully solvable for Jogvision owners, and probably a few other non-native Hercules controllers too.

Credit

The general technique of copying an outputs block from a native mapping into a custom one was pointed out years ago by DJ Juwansome in the AKAI AMX mapping thread — worth crediting since that’s what pointed me in the right direction.

2

Nice - thanks for sharing @Ailton_PAPA

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