DIY monome compatible grid w/ Adafruit NeoTrellis

The teensy mounts to this, then this mounts to the neotrellis pcb. It replaces free wiring.

I’ll have some of these in 2+ weeks (depending on pcb factory delays)


I’ll be ordering one of these, if they appear in you shop.

I’m (Really) not a fan of trailing wires.

Nice work!

Quick, possibly stupid question: are Norns scripts natively able to take advantage of the full RGB colour range available for the NeoTrellis-based Grids, or does colour support have to be added as an additional library or something?

I’m a noob, I’m afraid (Fates will be my first Monome thing, when I’ve assembled it), so don’t always know the correct terminology.


The monome serial protocol does not have any concept of color.

The only multi-color solution would be to change neo-grid firmware code to map the vari-brightness values to 16 different color values. Which is pretty similar to what some RGB midi grids do to differentiate midi values.

For the moment you can hard-code a single color in the neo-grid firmware. There’s also a branch or two being worked on to choose the color you want on boot.

Now - if you want to use the neo-grid as a MIDI device - then yeah - you could figure out some MIDI tomfoolery in your norns script to get RGB color values on the grid. (but that would need some other firmware other than mine)

Thanks for the quick reply!

That’s slightly disappointing, but not unexpected, given the Monome grid controllers are monochrome.

Funny you should say that…
I was kinda thinking along the same lines, actually.

I guess Norns scripts wouldn’t be able to deal with it as a MIDI device, in the same way, though.

And would also make the scripts a little too specific to my custom hardware to be useful to anyone else.

@jedgar may be able to suggest some Adafruit resources for MIDI neotrellis firmware - which could be more widely applicable to norns scripts (and other similar MIDI grid devices)

There’s also this thread on alternate grids where I believe someone is working on a MIDI->monome library for norns.

Two Fifty Six
image image

(Norns script is Zellen)


@toneburst these may be a good place to start if you’re using NeoTrellis as USB MIDI controller

Those both use the NeoTrellis M4 which is an 8x4 board with the M4 microcontroller built on, but it should translate pretty well to using a Feather M4, ItsyBitsy M4, Teensy, or other microcontroller and a few of the 4x4 NeoTrellis driver boards together like @okyeron’s 256 shown.


The notion of a 256 / Fates combo is intriguing. I hesitated to order the boards by now though. Do you think this would already work for someone who is very comfortable with building electronics but not at all with fixing or customizing code beyond closed language system?

Wow! You should make a few more of those…

In limited testing my code seems to work as expected with 256 so the code/firmware part should not need customizing. However, there may only be a handful of scripts that take advantage of a 256. (On norns I know awake and zellen work so far)

Does that answer your question?

Hardware wise - Power distribution here is still a question. I’ve got the power split between two sources right now. Might just run all the power from a 4A PSU via barrel jack - which is currently dangling off the side which is less than ideal.

Not likely :stuck_out_tongue_winking_eye:

Haha, I didn’t want to either !

Where might one find this?

Also! Congrats on the 256! Nice work.

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Paging @Gerald_Stevens, RGB courtesy phone please.

(Dunno if he’s ready to share)

When i had a 256 i did not find to many norns scripts that where compatible, sellen was one :slight_smile:

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Yes, it does - thank you! If I really go for it it would be partly to commit myself more to roll my own scripts.

I think it works well now, I’ll post it tonight. You select one of 8 palettes on boot up. I also applied an intensity gradient because that’s what the monome grid primarily uses to convey patch information. These palettes make patches beautiful. And add your own as RGB values in a matrix.


omg. this is absolutely amazing!

I definitely plan on open sourcing my design, however, I’m not 100% sure how I want to go about that. For example, I thought about trying to sell a batch of them (say 5 or so), and after they sold out release the files. I dunno.

Also: these are very expensive to print through a commercial service. I just priced out the printing cost on Shapeways and it is roughly $275 USD to print the top and bottom parts of the case using their cheapest materials. If I were to print a batch I reckon I could do it for cheaper (and probably better too given that I designed it).

Also: my current printer is not big enough to print these as single pieces, so I ended up printing several parts and glued them together. If there were enough people interested in buying a case, I might take the jump and invest in a larger printer (using the proceeds to finance the whole operation).

Here’s another picture with some of the many prototypes in the background:


Looks nice and I was considering doing something similar but was put off by having to do it in sections as my printer has max dimensions of 250 x 200mm.

I am considering other options and I wondered if people have ideas on fastening the top layer to the body without having visible bolts. Because aesthetics. I have an old 40h kit which I made with an aluminium top layer, and it just stays in place with gravity and a snug fit in the surrounding wood case, but I would prefer a more robust design. Do the ‘official’ grids have screw holes in the underside of the top surface and bolts from below?

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