MicroDexed - DX7 to go

Ah no… You are right… I am getting confused between mini and micro. I know one of them works with a pi and a 16x2 but the other is a teensy.

The screens I have are both pi-ish so I think I need to see if the work with mini?

Where is Floyd when I need him?

Yes, if you want to use a pi then minidexed is what you are looking for. What you get there is something like a “TX816/TX802” so about 8 DX7s in one small box.

Microdexed-touch has only 2 of these Instances at once but a lot of other features like chromatic sample playback, drum sampler, 2 “virtual analog” mono synths, mda epiano and various oscillators from Mutable instruments Braids. Further there is a 8 track sequencer with chains, arpeggiator with euclidean pattern mode and much more. It is more like a groovebox approach.

1 Like


Congrats :+1:

The job done here is just excellent. I really appreciate the detailed instructions and full open source documents.

1 Like

This might be the Teensy project you are looking for …


Extend your teensy 4.1 to interface with

  • analog line audio (6 in / 8 out) ( 6-in / 8-out 24-bit sound card - CS42448 )
    (a bit non std Eurorack 3 x6.5mm Stereo IN on the left, 4x6.5mm Stereo OUT on the right)
  • analog control voltages (8 in / 8 out: -10 to +10 volts) 1 6bit/sample, 8 x inputs and 8 x outputs ( ad7606, 2x ad5754 ) (3.5mm in the middle)
  • display: ST7735 (1.44 inch TFT LCD ST7735 SPI display module 128*128 8pin 65K color)
  • midi in/out
  • microSD socket breakout
  • USB-A host and USB-B devices
  • 4 potentiometers, 3 encoders w/switch

He’s too doing great things. Like this assembly tutorial (in music)

Nic is great, we use some of his code also in microdexed and were able to find and fix some nasty memory leaks together there. So other projects can benefit from that and will not run against the same wall as we did.

MicroDexed playing some Chords on Alpha Juno 2 (my latest Synth - last time i had contact with that was in school around 30 years ago)

1 Like

I had a bit of a scout around. I could only find non backlit mini buttons like these banks of 3-5 buttons that could fit in between the knobs of the current design.

But a totally crazy idea would be to add a NeoTrellis 4x4 but that would require an increase in form factor. I came with this idea of an ambidextrous beatbox with a bit more room for extra connectivity like CV IO or Line In. Sort of similar to the first Synthstrom Deluge prototype .

Not to Scale. But I think it might be roughly right as the NeoTrellis is 2.4"/60mm square and the TFT 2.8" Display area: 36.72(W)X48.96(H)mm.

1 Like

Thank you very much for your item scouting ! What you have in mind is basically very similar to a AKAI MPC Live i think. I do have one and it is great but to be honest, i do not use it very much (any more), even it can do so much more and behaving way more professional.

Maybe you are not aware of it but it is possible, right now, to use external USB and non USB MIDI Controllers with Microdexed. That can be a Midi Keyboard, a box with Faders/Sliders/Knobs, a mix of that or anything else that could send MIDI CC.
So you can get a 8-Fader box for 25$ ? and control every single volume level with it, for example.

The main downside is that the controls are not “prewired” and you have to map them to what you want them to be but there is even a auto-map function already in MicroDexed. And it is not inside the same enclosure, sure a downside.

MicroDexed was picked up for a competition at pcbway.

If you like it, use it - please feel free to leave some (positive?) comment at:


OK, this is now too easy to make, i need one. :slight_smile:

Ive never ordered PCBs before, and im looking at the order page now. Are all the default settings for this order safe to use as is?

I took it as a design challenge. I could not decide which side the button grid should go on so … make it work for lefties and righties with the same design.

Also if you recess the connectors to suit the board constraints underneath you can make a symmetrical top to get away from the different thickness of the left and right hand sides of the screen surrounds. (or perhaps that is just triggering my OCD :> Obsessively Clean Designs :>)

If you are not already have an account at pcbway, there is a link on our homepage with that you can make your first order of microdexed for “free” - you are then just paying for shipping, postage, taxes etc.

And yes, leave all options as they are, except you want to change the Quantity, minimum is 5 pieces last time i checked, but as said you will get 5 pieces for free when using the link (and you are a new user to pcbway)

The biggest current case problem is that you can not swap the SD Card without opening the lid. Not that you have to do that often, but it bugs me.
About the placement and lefties and righties, we do have a device reverse mode where the display output and the encoder input is flipped 180 degree. So the encoders are over the top of the display.

I have ordered 5x PCB… Anyone (UK) interested ?

1 Like

They arrived. Any UK guys fancy a DEXED board, let me know.


Does it have both midi and sound usb channels? How does the web UI connect? Looks amazing

1 Like

since we have only 1 usb-host port you can connect only one device - maybe it is working with a hub, i have not tried it.
usb audio is for all internal generated sound. so you connect teensy internal micro-usb to pc and either a usb midi keyboard/controller, game pad etc. to usb-host.

1 Like