DIY monome compatible grid w/ Adafruit NeoTrellis

@thopa see here for some pictures:

I used the 5v (VIN) pin on the teensy rather than the 3.3v pin as I believe the neotrellis boards want 5v input (and that should hold up better when lots of leds are on). Not sure if it matters using GND vs AGND.

See the adafruit neotrellis guide for more on wiring basics


Do you think the enclosure will fit 3mm spacers/screws without any modifications @okyeron?

Is the offworld usb splitter needed if i want to connect a 128 Neotrellis grid to a Fates?

Not sure. I’d want to measure the width of the hex spacer and compare. Might depend on the specific hardware used. Also not sure how big the screw holes are )would need to check the file later)


So far at lowered brightness mine seems to do ok without splitting the power out. It needs a bit more testing.

I do have some offworld’s built and for sale in my shop if you want one.

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A question about the case. Is there a reason why one layers is 5mm foam? Or could it also be another material of 5mm? And what would happen if it is 4 or 6 mm?

What DIY arc is that?

It’d be skinnier or thicker? :stuck_out_tongue:
(this kinda gets into personal preferences on how you want the device to look/feel)

I was going for what I thought is an ideal ratio of the button sticking up over the top panel. Call it button height or something. With a 3mm top panel + a 5mm spacer, the button height is enough that when depressed, they are still slightly above the top panel height. This is also pretty close to how this looks on the original monome grid. This also lets me use an 11mm spacer for the whole stack (and I’ve got a bunch of 11mm spacers around for RasPi stuff)

I’ve been searching for a laser cuttable material to use as an internal spacer for awhile, but only recently got turned on to EVA. It’s nice because it comes in a range of thicknesses and it’s not terribly expensive.

So - you could just use a layer of 3mm acrylic instead, but you’ll need to adjust the spacer height - unfortunately that means the next reasonable spacer is gonna be 8mm and you’ll have 1mm of extra space.

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I will note that after factoring my time in, it would have been nearly the same as buying the real thing. This was an exercise in SMD torture getting all of the LEDs placed.


Fantastic, thank you for the info and for testing it out! Definitely going to build one of these with my Teensy 3.1 at some point.

This is great!
As soon as i can have some spare cash im all in for getting the neotrellis boards and start testing.
Got to say those grids look stunning…that purple color!
Thanks all for the wiring pictures and work, i feel much less intimidated with this project than i was before.

Ok do im in :slight_smile: ordered the neotrellis pcbs now :slight_smile:
@okyeron where can i find that script you mention to get fates working with this?
Is that the teensy file?


Got mine up and running this morning. Very painless process. Only time I got slightly worried was when I ran the multitrellis basic example and the whole grid went bananas. But quickly understood that this was due to full LED brightness and not enough power from the teensy. Excited to see if the lasered plywood case I ordered will fit. will update with pics as soon as it’s done. Amazing work.


Question: have anyone experimented with what color handles different brightness best? I might need a case to properly test. I just felt that the difference in brightness was not optimal using cheat codes(with white LEDs).

Just to be sure is this the correct pads adressing for a 128 neotrellis?



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I was about to ask this too :slight_smile: 20 chars of gracias!

Are you using the @okyeron code? If yes, those are not the correct addresses if you don’t want to modify the code.

I believe it is:

1 0x2E
2 0x2F
3 0x31
4 0x33
5 0x37
6 0x3F
7 0x39
8 0x35

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Following @okeyron code i think it’s like that:


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Nope. Looking at the addresses declared in the code, the following addresses are used:

Line 50 and 51

  { Adafruit_NeoTrellis(0x33), Adafruit_NeoTrellis(0x31), Adafruit_NeoTrellis(0x2F), Adafruit_NeoTrellis(0x2E)}, // top row
  { Adafruit_NeoTrellis(0x35), Adafruit_NeoTrellis(0x39), Adafruit_NeoTrellis(0x3F), Adafruit_NeoTrellis(0x37) } // bottom row

If you want to use the addresses you’ve listed to need to modify these lines.

Ok got it and the addressing pads are correct?

Address list/cheat sheet is here:

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more later when i have time, but a quick note…

It does not matter what addresses you use - but you just need to get them in the right order in the code. The addresses in the code are when you’re looking at the back of the boards right to left wait… left to right

I suggest testing with the multitrellis basic sketch first to get your addresses sorted out before you try loading the neotrellis-monome code.