OMX-27 - a DIY Mechanical-Key Keyboard/Sequencer

ØMX-27 is a DIY hardware MIDI controller and sequencer with RGB LED backlit mechanical key switches.


  • 27 RGB backlit mechanical key switches
  • 5 Potentiometers
  • 1 Encoder (w/ switch)
  • OLED display (32x128)
  • Hardware MIDI Out (1/8" minijack, Type A/B switchable)
  • CV pitch and CV Gate outputs
  • Teensy 3.2 microcontroller


(modes are still work in progress and subject to change)

MIDI keyboard

  • sends USB-MIDI and hardware MIDI notes along with 5 CC’s.
  • sends CV pitch and CV gate (limited to 4 octave range)

Sequencer 1 - single pattern

  • 8 patterns of 16 steps
  • plays one pattern at a time
  • variable pattern length

Sequencer 2 - multi pattern

  • 8 patterns of 16 steps
  • plays all patterns at the same time
  • variable pattern length (for each pattern)

(still lots to do in the sequencer code)


BOM, build info, Firmware source, and case designs are available on Github.


Why not? :grin:

Use it to control ORAC, Organelle Mother (Organelle patches on pi devices), norns, PiSound, softsynths (iPad/computer/etc.), modular, etc.

Reminder - This is DIY

This is a Do It Yourself project. It’s designed to be easy to build for someone with basic thru-hole soldering skills (with an smd-assembled pcb). This is not intended to be a “finished” product for purchase.

Per the lines trade rules - please, no discussion of buying/selling in this thread.

Use this thread to ask questions about building, software/tech-issues, etc… Or DM me for a link to Discord server for support.



How / When?

Kits are available for purchase.


Proper Youtube demo to come soon.

A few quickie instagram demos:

Social Hashtag: #omx27


That’s so handy.
Nice work S.


Absolutely gorgeous!! That looks like a ton of fun, the videos on insta are :fire:


This is fantastic! Inspiring build!

1 Like

That PCB is beautiful :heart_eyes:

Can’t wait to build one.

Beautiful, love it.

Wait - what - B to C? :slight_smile:

(oh - 16 keys - I get it.)

1 Like

looks great, love the 909/yamaha su700 style buttons! I will try to build one when available

The buttons are what stood out to me, too — I’m obsessed. Might have to buy one just for those buttons…

1 Like

I love it.

I think I would like to use it with my Norns more so than as a stand alone cv controller.

Is there any hardware related reason I couldn’t modify the firmware to decouple the led,lcd, and cv outputs from the key and knob inputs? So that my Norns or other host could set the led and cv out in response to things going on in a script?

Very cool project!

I’ll be doing a large-ish buy of the keycaps, so will likely have some to offer as sets.

It’ll be hackable sure. I’m pretty sure what you describe would be doable. :slight_smile:


Awesome! will there be an OMX-88? Kidding but also not kidding :smile:

1 Like

This could be a prototype for a 60% mechanical keyboard which doubles as a midi controller/sequencer. Looks interesting!

1 Like

@okyeron, I’m assuming I could mount some hot swap sockets to this board? You haven’t happened to have tried this already, have you?

I’ve not tried it, no.

Looked at the kailh hot swap sockets for a minute but decided i would rather have a slimmer profile than what I could get with those.

I don’t really know how you could mount them on the OMX tho. I thought you needed to have SMD pads to attach them to the pcb (kailh sockets)?

Doing a quick search on Keebtalk, I see there’s a MillMax socket and mention of a couple different MillMax models (7305 and the 0305). Kinda $$ at ~$0.35 each (in quantity)

Oh, I totally didn’t think about the profile or the fact one needs the mounting pads on the PCB. I definitely got ahead of myself there :man_facepalming:

Those millmax sockets look interesting. I haven’t seen those before. Pricey? Yes, a little. But I’m tempted to test them out (provided enough interest is out there for you to warrant a run of these of course). Thanks for the tip!

1 Like

kit just landed today. looking forward to building it.


Wait, how did this completely slip past my radar? The kits are available now?!

Edit: Ah, I think I see it now. On the interest check forum?

Slow rollout!

I sent out email to people that did the express interest list awhile back. (So far)

I’m only really able to get like 10-20 kits ready/prepped in a week so it’s gonna take some time. :smiley:


Just finished my build. Went together smooth until I broke the last pot knob as I put it on… but fortunately there was a spare!


Ooooh… do I need to make a note somewhere to not press the knobs down hard?