Below are links to product support pages:
Legacy RK-002 Firmware update page
This is the updater which does not read back update information; one-way update is possible if your MIDI interface supports MIDI System Exclusive and powers the RK-002
The Legacy MOD(former FM) firmware has free parameter mapping but here are some templates for controlling various synthesizers with the MOD Firmware so you don’t have to figure out those SysEx commands for that yourself:
volca FM controller template
volca Kick controller template
volca Keys controller template
Roland Boutique range controller template
RK-002/DUY custom firmwares
RK-002/DUY Exchange Portal
The most extensive library and reliable updater on the RK-002. Loopback communication to check proper connection and ability to program the cable with custom MIDI processors via the Arduino IDE.
Online settings manager page
Download the RK-004 enclosure STL Model file
The enclosure goes together with the RK-402 Aluminium frontpanel.
Info on using the RPi as USB host or sequencer master is on this page