Launchpad Pro Polyphony Maker

A custom firmware for the Novation Launchpad Pro (mk1) that transforms the launchpad into a MIDI processor which captures note events in the given channels and splits them into multiple channels. This enables polychaining and transforms monophonic instruments (like the Digitakt) into fully playable synthesizers of up to 16 voices, ideal for "dawless" setups. It also provides a multi-octave keyboard and 8 pages of 8 faders and 8 buttons for sending CC messages, quite handy for mapping parameters in your DAW. The left side buttons ("shift", "click", etc.) are active regardless of the page we are on.

The current version supports the basic polyphony generator functionality and enables the selection of start/end of the MIDI channel range for the polyphony splitter and 4 modes of voice stealing:

• Voice steal off: Once the maximum polyphony is reached, new incoming notes are discarded.
• Discard oldest: The oldest note makes room for incoming ones.
• Discard highest: The note with the highest pitch is removed.
• Discard lowest: The note with the lowest pitch is removed.

From within the available voices, round robin scheduling is used to find the next playable channel. This allows single note melodic lines in instruments with long releases to sound more natural, as we are not abruptly stopping the sound of a channel to play a new note.

The main view is accessed pressing the "session" button on the top of the device and it allows you to see the number of voices currently in use, bypassing the polyphony generator and selecting the method of voice stealing.

The keyboard page is available by pressing the "note" button. It provides a 7 octave keyboard, though only 4 octaves can be seen at given time. Each octave has a distinct color. The keyboard can also be transposed for ease of playing in different keys. The root note is represented by the white note on the keyboard.

The faders page, access through the "device" button,  provides 8 faders per page. It has a limited resolution, given that we compress the 0-127 range into only 8 values, but can still be quite nice. Different CC values are mapped to each fader page, ranging  from CC 0 to CC 63.

Pressing the "Setup" button switches to the configuration page, where three groups of 16 pads are used to select the MIDI start, MIDI end and channels being captured from the MIDI in. The start and end ranges define the number of voices available for polyphonic distribution. Exiting the Setup page will save the changes so that they persist through power cycles.

Installation

This project is open source (https://git.badd10de.dev/launchpad-polymaker/) but your support will allow me to add new features, such as multiple profile pages and a note mode with scales support. The provided sysex file can be uploaded into your Launchpad by holding setup while powering the device and using your favorite sysex transfer file. In Linux I use:

amidi -p hw:4,0,0 -s launchpad_pro.syx -i 20

Where "hw:4,0,0" is your device ID, which can be found with amidi -l.

For more information, feel free to take a look at my website.