Are the monome Arc, Grid, etc open source?

The monome site explicitly calls out that the Aleph and Norns are open source, and doesn’t mention this for Grid, Arc, Crow, etc.

Are they open source? If so, where can I find the appropriate files?

Simple answer is no if you’re talkin about the hardware for those three. Still, a few diy enthusiasts have made one-offs and versions of grid and arc with a bit of help from brian.

Crow fits their ethos: providing a hardware idea and empowering users to rewrite scripts + apps to repurpose the device. I think crow is still pretty flexible within the framework provided and doesn’t really need new fw yet but if you wanna tackle building something similar then contact @Galapagoose.

Just checked your website and you seem experienced. Consider teletype, the trilogy series of modules (mp, ww, kr, es, and ansible), or 3rd party hardware based on the same control/routing schemes like (telex by @bpcmusic ).

TT and expander series are all open now and the trilogy modules can usually be found secondhand at a reasonable price. They each seem to have alt firmware already developed & it’s been exciting to see new platform multipass by @scanner_darkly. It’s easier than ever to prototype and develop apps on hardware that has been reliably tested for years.

Here are various links to pages that will probably be of help

1 Like

mod note: i edited the post above with a link to the arc clone github, not the site selling kits

@NoraCodes what are you looking to do?


Okay, thank you for clarifying!

It’s a bummer, as there’s no way I’ll be able to afford anything in the ecosystem for a forseeable future (Arc, for instance, costs on the order of 3-5x as much as I spend on nonessentials in a month). That said, I appreciate the resources you’ve linked, and I’ll definitely check them out.

Basically, run a group buy of parts for those of us who can solder, but can’t shell out $900 for an expression controller. A friend of mine recently did something similar with the 16n faderbank and it went very well; I use the result daily.

I will probably do something less high-quality based on the links provided, or just build something completely new based on the same concept, since it seems like I’ll have to do most of the engineering myself anyway - though that Grids reverse engineering repo does look handy!

Many thanks all!


same (it’s more than my monthly living cost, lol) - I have one but it’s honestly nowhere close to my favorite monome thing and super not necessary if you’re interested in the ecosystem as a whole imo. I’d recommend the adafruit grid or if you care about build quality more than existing application support I’d highly recommend picking up an older non-varibright edition of a 128 or 64 grid. norns shield is a no-brainer if ya like code & dig the ethos. I think a caveat of ansible is that you can’t currently use a DIY version or get too far with an older non-varibright unfortunately, but someone can correct me on that.

my favorite monome tool is a walnut 64 grid : ) I think I picked mine up used for around $300 and mostly use it with my own apps


respectfully, i’d like to assure you all that the arc is not priced at $900 because i’m out to steal your money and get rich. the amount of complex engineering and manufacturing that went into the design is astonishing— the trial and error, sunk r&d costs for tooling and prototyping, and production setbacks all factor into the price. and do not presuppose that these just arrive perfectly to us from a factory whereupon we box and ship— furthest from possible. we hand-assemble and painstakingly calibrate these, whereupon we often must set aside many components for rework or send them back to the machine shop. (@dan_derks participated in the last build, he can chime in). the arc has literally made me insane at times. if we make it again, i’d consider raising the price.

however— this was all to achieve a level of quality and experience that i was seeking. if i was going to make a knob device with such minimal input, it had to be right, all around. i think it came out pretty well.

of course, anyone could make a compatible device quite easily because the protocol is open source, and has been since we started making things. theoretically anyone with basic electronics knowledge could put together a working clone with a teensy, some encoders, some LED rings, and google.

in fact, like the 16n (glad everyone is enjoying that, btw), i’m hoping to continue working on a more generalized set of DIY open-source materials for making your own controllers. i strongly feel that creating your own controller gets you further.

lastly, with respect, there are professionals for whom this gear is not considered non-essential, who regularly spend substantially more to get their toolset together. given that our instruments are short-run for a niche audience, we fall into an awkward cross-section: we’re not making toy TE pocket operators, nor extravagant Moog synths.


Absolutely. I didn’t mean to imply that at all. I think it’s a beautiful piece of kit and I don’t presume that a clone I built for a few hundred dollars would be anywhere near the same quality. I apologise for playing down the importance of the r&d work you’ve done, too; it’s clearly made a big difference for a lot of people - myself included!

I’m not in any way questioning whether Arc or other devices in the monome ecosystem are worth the price, either. If I could afford a Grid, or if, as you say, it was an essential item for me, I’d buy one in a heartbeat.

That doesn’t change that fact that I can’t afford them, though, or that it’s a bummer that they’re not open source. But that’s your decision, and if I want something similar I can put in the engineering hours myself - and I think I will, if I can find those hours.

Again, apologies if I’ve offended in any way.


i think part of what brian is getting at is that there is little value to be derived from open-sourcing the hardware for arc. i’m not even sure what that would mean. if you had the mechanical drawings or whatever, you would still have to fabricate the thing!

the serial protocol is open source. so it’s pretty trivial to make an MCU and encoder behave like an arc, which is what the projects linked above are all about. TheSlowGrowth’s clone project goes pretty far by using the same processor family, which is a bit of a beast… but a Teensy or Feather will do just as well if you’re rolling your own controller.

plus, by rolling your own you gain the freedom to change the functionality to be closer what you want. like, i dunno, adding MIDI output.


This thread was started as a question and the question has been answered, so this is just a superfluous opinion but… Arc is not just an expression controller. It’s truly an instrument. If you haven’t used one, it’s hard to express how unlike other rotary controllers it is. Same goes for the grid. Open sourcing this stuff would make it more widely available I guess, but it seems unlikely that any other project could match the quality, and the experience of actually using this specific hardware feels like it makes the difference. I made a stupid choice selling my monome gear earlier this year, and even though it was a bit painful, I sold some stuff to get it back again.


I have a grid clone and a fates, I also have an original grid and touched a real norns. As much as I love that I have these devices I could probably never justify myself purchasing, I have to admit there is a huge difference between them.
My diy grid took about a month to be fine tuned to work reliably, a huge amount of time was spent on moving resoldering and readjusting so the feel is good on it and still some pads have to be pressed with much more strength to be recognised.
No comparison to the original one which feels just amazing. Also the leds are so beautiful on the original grid. A beautiful warm glow… mesmerising.
What I want to say is that when you buy such a product it kind of is a piece of art itself. The level of perfection and detail on such a product is what makes it worth it for me.

On the contrary. If, as you say, Arc and Grid are so unique as to really surpass every other rotary and grid-based controller out there - which I don’t necessarily doubt - I think it could be a huge service to the community to open source them. As I mentioned, this is entirely @tehn’s decision, and I fully respect it; but I do think it’s important to acknowledge that open sourcing something isn’t just giving the world a license to manufacture bad duplicates. That is inevitable, of course, as we see with Mutable clones, Arduino derivatives, et cetera.

But, similarly, it drives innovation. Much like the original vision of the patent system, an open source piece of hardware can both remain the pinnacle of its category and become the basis of an entirely new one.

As @LT6J so beautifully puts it:

No comparison to the original one which feels just amazing. Also the leds are so beautiful on the original grid. A beautiful warm glow… mesmerising.
What I want to say is that when you buy such a product it kind of is a piece of art itself.

Undoubtedly, this is a distinction that comes only from the genuine love and care put in during not just design, but also assembly and quality assurance.

That said, @LT6J also points out that an open source Grid would put in the community’s hands the solution to some other problems:

I don’t say this to argue that these items should be released as open source - they’re not, that’s fine - but to make another point. While it’s true that I could make something similar, but much less polished, based on the NeoTrellis or some other existing hardware, or roll my own grid entirely, this statement:

isn’t quite right! True, rolling my own from scratch might allow me to alter the basic assumptions of the device, but in the case of the Grid, releasing it as an open-source platform from which to build additional instruments could launch an ecosystem of new hardware, and especially software. How much easier to take @tehn’s wonderful design and add MIDI, or multicoloration, or wireless capability, or a hundred other things, than to build a grid from scratch? How much duplicated effort saved?

See, for instance, the Pique and CV controller thereof, a variant of Peaks which, in my opinion, improves in some areas and fails in others, but is, overall, much more suited for my use case. It’s not as simple as “Pique is a smaller, cheaper Peaks” - it has new functionality and an altered use case entirely.

So, while I want to be clear that I am just using the Grid as an example here and am not trying to argue with @tehn’s decision not to release the design, I do think that it’s important to recognize that open sourcing a hardware design is more than giving people a license to make knock-offs.


I know the feeling of the arcs is an experience in near perfection- I miss mine very much

I think that the Bella trill sensors are very good for the price and that they are native i2c - while nothing like the arc they do remind me something of that functionality, I wonder if any of the arc apps would work, even in a cutdown form?


Interesting idea! I hadn’t really paid attention to the Bela trills.

(As a former owner of an Arc, it’s one of the few things I “regret” selling. It’s not essential to my workflow but it is one of the most beautiful objects I’ve come across).

While I agree with everything @zebra said, I do think a project such as 16n is the exception that proves the rule. With a simple and narrow enough feature set, I believe OSH can potentially be successful.

But I don’t think that describes the arc or the grid. Those devices are complicated and flexible enough that it just makes sense to manufacture them to a high quality spec.

That being said, it’s not like there are bright lines around these categories. But hopefully some consideration of what makes 16n different from an arc, will be illuminating.

1 Like

Fyi, I’ve managed to get two LaunchPad Mini Mk3 working together as a Grid 128 using the midigrid library. To use you need to override the grid require line in each library script you want to use. More details here: Norns: alternative grids