Hi all,
I designed a 1U Eurorack MIDI Controller programmed specifically for Yarns and wanted to share with you all for feedback. I made videos below showing what it can do and why. Would love to know what you think.

Just to point out - the videos are full of DIY Mutable modules I built for myself. If sharing on this forum is a problem I’ll remove it. I owe a huge thanks to Olivier for sharing his incredible designs and code, I learned a ton from studying and building them and this module was the result. Thank you.
What is it:
A MIDI OUT keyboard controller that will work with any MIDI instrument or MIDI-to-CV interface, but is specifically programmed to work with Yarns. So thinking of calling it Needles. It connects to Yarns’ MIDI IN from behind.
Why:
Yarns is deep and funky and I like it a lot. Since it has four independent channels, each with it’s own sequencer, clock division, arp, oscillator etc - controlling it on the fly by bringing out its features using it’s MIDI implementation turns it into a powerful multi-track composing tool that can be edited, overdubbed and manipulated live. No computer.
- 1U 66hp
- 1.5 octave keyboard
- Octave selection with LED indicators.
- Rest, Tie, Slide, Rest and Tie x 3 and x 7
- Legato on/off - (Trigger Velocity Scale on/off in 4T)
- Portamento
- Vibrato (Mod Wheel)
- Vibrato Speed (Oscillator Shape with Shift)
- Tuning System
- Velocity - (Trigger Velocity Depth in 4T) (maybe double as pitch bend)
- Arp Range - (RG in 4T)
- Arp Direction - (Trigger Shape in 4T)
- Arp Pattern - (RP in 4T)
- Fine Tune - (Trigger Duration in 4T)
- Clock Division & Gate Length
- Midi channel selector
- Shift button - Latch and other functions
- Two segment displays - red for Midi channel, green for values feedback
- Various combo buttons to access and change functions
An overview of the module:
Recording and overdubbing live:
Flipping the 4T switch changes some knobs to control specific functions for 4T:
3 Arps and a Vocoder:
Simple transpositions:
It runs on an Atmega 328 and Arduino, and all the CC assignments can be changed in code easily. I’ve been playing and testing it for a few months now, tweaking and experimenting with the layout. The hardware is solid, doesn’t crash or act weird or effect Yarns in any unexpected way. It’s my version 1.0 though and I have some tweaks to make (like power regulation if running from 12v, it runs now on 5v). The code also works smooth but some of it is hacked together awkwardly, which I’m going over.
Long post! Thanks for reading if you got all the way down here…