Codename DW-666

An embedded MIDI routing app to interface an Arturia Beatstep with a Korg DW-6000.

Provides immediate control and modern tactile UI over the sound parameters of a vintage-but-knobless synthesizer.

Main target is STM32H7 "devebox" board because it is very juicy. May also target STM32F4 "blackpill" board but my one board is dead so I don't know.

Uses embassy crates for #[nostd] async Rust support.

Still under development, probably forever.

Interface

Each Beatstep knobs controls the value of a parameter of the DW6000.

Turning the big top left knob anytime will make those sweet NJM2069s sweep and swoosh by controlling filter cutoff.

The small top right knob always controls filter resonance becauPEWPEWPEW.

The top right 4 pads control some on/off parameters like Chorus and ??? (TODO see what code says)

Parameter pages

There are 15 knobs left but more than 50 parameters! Parameters are thus grouped in pages.

The top left 4 pads on the Beatstep which the parameter page is active.

Quick tap on a pad to switch to the associated page.

Hold down a pad to quick-edit that page's parameters, then release to go back to the previous page

[[INSERT HERE: A nice markdown table showing map of pages, knobs and parameters.]]

Quick patch change

Hold down one of the 8 lower pad and then tap on a upper pad.

8 pads (low) x 8 pads (high) = 64 combinations

Number of patches on the DW-6000? 64

Coincidence? I think not.

Build & Run

Requires nightly, just because #![feature(alloc_error_handler)] isn't stabilized. See rust-lang/rust#66740

Have an STLink/v2 or DAP42 SWD probe connected to the blackpill.

rustup +nightly target add thumbv7em-none-eabihf
cargo run

To fix probe USB permissions, edit udev rules in some file like /etc/udev/rules.d/50-usb-serial.rules

# CMSIS-DAP DAP42 probe
SUBSYSTEMS=="usb", ATTRS{idVendor}=="1209", ATTRS{idProduct}=="da42", MODE="0666", SYMLINK+="dap42"
SUBSYSTEMS=="usb", ATTRS{idVendor}=="0483", ATTRS{idProduct}=="3748", MODE="0666"

Then reload the rules with sudo udevadm control --reload-rules and reconnect the probe.

TODO

• Make it run again, dog magnit!

• Still requires an external computer to route USB MIDI bewteen Beatstep and board. USB MIDI host co-board (using Atmel SAM D21) undergoing development in a separate project. Meanwhile, ALSA's aconnect is a friend.

• An LCD screen to display current patch values would be nice. Attempts to use ILI9341 have failed up to here, halp.

• Using async Rust would make some code much cleaner (callbacks, uh). USB Host project (see above) might provide answers.

• Use native Beatstep sequences to drive an arpeggiator

• Make that external LFO2 thingie better harder stronger faster and document it too

• Record a small video of the whole thing in action

• Make music, not softwar!