Adafruit HELLA Grid Controller Kit




Looks fun, especially given that monome DIY kits no longer exist AFAIK! The lack of RGB LEDs and dimming puts me off a bit, but it would probably be fairly easy to design PCBs which tool RGB LEDs. Has anyone used these particular elastomer keypads? Do they feel good?


It would be a lot more fun if it could be made to speak serialosc. Would require a good size chunk of effort though.


what’s the take on extending serialosc for generic controllers? A lot of the namespace is related to the symbol monome. If I make a firmware identify as Monome is that a mergable PR?


Isn’t there already an arduinome firmware that speaks serialosc? I built an arduinome a long time ago (I think it’s been more than 10 years :hushed:) and I still have the firmware I used for that lying around (I’m a hoarder when it comes to code). I got it from here, but they apparently moved to another website which doesn’t exist anymore. I think at that time the program used to communicate wasn’t serialosc, but the protocol must’ve been similar, right? Otherwise, how would old monomes work with current versions of serialosc? I’m sure a few things would have to be added/changed, but I think it should already be part of the way there. I don’t have the time to investigate further right now, but if anyone wants to have a look, be my guest.


So I have a firmware for adafruit grid that talks mext here: - it was made for 8x8 version, but should be fairly easy to update to 8x16.


These Arduino OSC projects appear to have converged into the CNMAT OSC library for 32 bit microcontrollers. This rules out the possibility for any 8bit AVR (Arduino, Teensy++) to operate as a native OSC device.


This is great, thanks. I began on a similar road which led me to mext_methods.c. It looks like you have already covered this well.


Could you elaborate on your point of Teensy being ruled out?

I’m currently hacking on something* based on the trellis board and would like to use Teensy (3.2) if possible


Does it mean that you can easily send/receive OSC messages between Max or PD and Arduino ? Via USB ?


In this case it’s making an arduino (or similar) behave like a monome device (grid, etc.)

So yes - that would include sending OSC messages from PD or Max to the arduino.

I have the @szymon_k’s code mentioned above loaded on a Teensy (3.6 for my test) and my computer can recognize it as a serialosc device (plugged in via USB). Now I just gotta get my diy grid built. :slight_smile:


Since this thread got bumped I started looking into this again and am considering trying to design a dimmable Trellis clone so that it’d be possible to build a more modern DIY grid. I’ve never worked with lots of LEDs before but it seems like there are driver chips with suitable capabilities, like this one:

Does anyone here have any experience with making individually dimmable LED matrices?


Oh - I was gonna look up last night (if trellis supports variable brightness)

(reading the datasheets, etc.) Looks like the HT16K33 chip on the Trellis can dim the entire display (or maybe rows at a time) but not individual leds.

So - maybe this is good timing. I’m in the midst of redesigning the Trellis board for my own needs, so I could look into using the TLC59116 chip instead. There seem to be a number of github repos with TLC59116/arduino code, so one would hope it’s just a matter of getting the i2c commands right and interpreting the serialosc info

EDIT - I think the TLC59116 is missing “keyscan” which is needed to get button presses. Investigating other chip possibilities.


I was reading this documentation


Ok - I may have misunderstood your point. Not sure why someone would want to use an 8bit AVR at this point tho


thought I’d leave this here in case it’s useful:

128 and appears to be variable brightness …
though could this be a trick of the light, so to speak. ?

more info here: stray technologies wiki

runs on a teensy / shows up as a 40h ( with serialsosc ) on the mac.

I’d like to get a 64 one working with the pi sometime… -something along the lines of an off grid electro-acoustic sampling instrument …it’d be an interesting project, though with my limited knowledge set it’s definitely hovering around the outer most edge of the realms of possibility. atm anyway.


I think it’s a trick of the light - pwm leds maybe not getting enough power perhaps?


Agreed. The Bliptronome was never able to handle variable brightness.

I’m intrigued by this enclosure, though! I’ve got two Bliptronomes and a laser cutter. What interesting possibilities…


Yep, I’m pretty sure it’s just a LED driver chip, without keypad capabilities. I’m doing a cursory search for chips which do both. Otherwise I was thinking of using a dedicated keypad scanning IC or even just an MCU for the key scanning, and make the PCBs in 8x8 size to reduce the number of redundant ICs.

EDIT: all I can find is this one: which scans 64 buttons and can drive 8 LEDs, so gets you some of the way, but is only available in extremely non-DIY friendly packages (even worse than the TLC59116 being TSSOP)


Yeah - I’ve been considering the same, and had similar trouble finding a one-chip solution for that number of inputs+leds

I’m looking at the TLC59116-Q1 for LEDs and TCA6408A for buttons. Yeah - they are TSSOP, but I don’t mind that. I’m also a glutton for punishment as I’m using 0603 LEDs for my trellis remix board. :smile:

I’m trying to determine if it would significantly save $ on pcb manufacture to stay with a smaller board (and tile them) vs a full 8x8. Guess I should do a mock up and see what the prices look like.

EDIT - FWIW… if my prototype stuff works ok I may be able to offer a small number of DIY “kits” with pre-soldered chips and button pads.