introducing ADDAC System - arduino analog->digital->an

New Interfaces for Analog Synthesizers.

Moderators: Kent, __ag

Did you liked it's concept?

Poll ended at Fri Mar 05, 2010 1:04 am

Total votes: 49

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introducing ADDAC System - arduino analog->digital->an

Post by __ag » Fri Feb 19, 2010 1:04 am

Hello all,

so arduino meets 16bit 8 channel CV output
(this are NOT PWM outputs!)

I've been building this modular system for digital generation of complex waves based on math equations, this is also meant to be a platform to integrate the analog world to a computer for higher resolution applications where midi isn't precise enough, so it has a 10bit ADC (0-1023) and 16 bit DAC (0 -65535)
It is also a standalone tool, no computer is needed to run it, after the code is uploaded with all the functions assigned it's just another module on the cabinet

a truly open interface based on the arduino platform, with basic control through java programming and full control with c++

although it's not all finished yet, all electronics are assembled and tested, but still a lot more programming to do in the arduino library to make everything easier for low level programmers, still i thought of posting this here to get some reactions and hopefully help me polishing the final v001 before making everything available.
in the next couple weeks a lot more info will be added to the site, including more pictures, demonstration videos and a lot more info

it's hard to describe the whole concept briefly
please take a look at:

soon it will be hosted here:

get in touch


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Post by BugBrand » Fri Feb 19, 2010 3:55 am

Great to see you here Andre!
(I know him from previous work -- top guy!)

To get interest a-go-go, lets post some of the system pics:::

Certainly looking yummy!
Can you give some more descriptions of the module functions for people? From what I remember you were going to use things like Wii Nunchucks etc?


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Post by tIB » Fri Feb 19, 2010 4:10 am

for the lazy


Id love to hear more about this...

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Post by Veqtor » Fri Feb 19, 2010 5:50 am

Wow, this is exactly what I have been thinking about that someone ought to do for the last couple of days, wish I'd found this earlier.

So, can we expect kits also? Are these programmed like the arduino, will you be releasing a library which facilitates audio-rate functions?

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Post by D/A A/D » Fri Feb 19, 2010 8:11 am

Really awesome!

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Post by tortug » Fri Feb 19, 2010 8:23 am

Great! :tu:

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Post by JP » Fri Feb 19, 2010 10:10 am

This would make writing Monome apps that directly control a modular through a max patch so easy. Big +1. Fingers crossed it follows some of the open ethos that arduino does.

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Post by glacial23 » Fri Feb 19, 2010 11:13 am

Very interesting. I've been poking around with a similar idea, though I'm using a quad 8-bit DAC.

I might be interested in some of this if there are kit/barebones options.

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Post by knobs. » Fri Feb 19, 2010 1:06 pm

pretty much my dream. please make it possible. i'm gonna tell stretta now (:

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Post by dkcg » Fri Feb 19, 2010 2:21 pm

I would love to see this as a kits with euro faceplates, else finished modules.

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Post by Soy Sos » Fri Feb 19, 2010 2:37 pm

Someone please explain some of the possible applications of this thing
for the non Arduino literate folks like myself.

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Post by dk » Fri Feb 19, 2010 2:47 pm

Soy Sos wrote:Someone please explain some of the possible applications of this thing
for the non Arduino literate folks like myself.
You can think of it along the lines of the tiptop z-dsp: it's a sort of blank-slate module into which software can be loaded to do arbitrary processing of CVs. People will be able to write programs which treat the jacks and controls on this thing as parameters. It could be a quantizer, clock divider, random voltage generator, whatever, just based on the code that's running on the arduino. At the same time, it looks like it'll have a nice library to allow novice arduino developers to get started quickly.

I'm really looking forward to this. The ethernet interface in particular could be really fun.

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Post by Soy Sos » Fri Feb 19, 2010 3:05 pm

I vote hell yes!

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Post by BananaPlug » Fri Feb 19, 2010 3:29 pm

Very nice. If you have any sense of how much can be going on before you start running out of cycles please share.

What provisions are there for handling some inputs on an interrupt driven basis and for internal clock timing interrupts? Is any logic delegated to the input modules. Is it all simple polling?

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Post by deastman » Fri Feb 19, 2010 3:44 pm

This would be awesome! I've been giving myself a headache for months, looking over specs for various A/D/A options to use with the Arduino. I can't see the pictures posted above (blocked by my company's !@%^!@ proxy server), but will this take the form of an Arduino shield?

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Post by wetterberg » Fri Feb 19, 2010 4:23 pm

it's a module, deastman. With various pretty little extension bits.

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Post by Mood Organ » Fri Feb 19, 2010 5:12 pm

Not only am I interested... I'm so interested that I might have to get a Euro case just for this. I suggested pretty much this exact idea (minus any technical insight) for Blacet so it's nice to see it pop up somewhere at least. Sounds like the CV inputs could handle Frac levels, but I guess the output would max out at +10V.

This is some real mind-boggling shit right here :goo: Seems like it would be great for quantizing to weird non-12tet scales, bizarro gate logic schemes, messed up ways of combining signals, lots of stuff really...

Can it communicate via Ethernet while it's running? So like, you could feed data and the module converts it to CV somehow... or whenever a gate fires, the module sends a signal to my computer that tells it to open a web browser, go to this thread and add a new post that says :nuke:

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Post by Qmod » Fri Feb 19, 2010 5:34 pm

Mood Organ wrote:I might have to get a Euro case just for this.
That's my plan also... (notebook & arduino mini case so i don't have to cart the monster to have fun with a monster)


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Post by ezekiel » Fri Feb 19, 2010 9:34 pm

Very cool. We need an open-architecture universal module.

I imagine the "universal module with digital insides and analog outsides" more the way Doepfer did--such that, if no one told you, you might not know it was digital from the outside. So, I am more waiting for an 8-HP universal module looking like an A-136, A-137-1, A-137-2, or A-189-1, with 3 inputs, 2 outputs, and 5 knobs or so. Or, like an A-166, Zorlon Cannon, or Malgorithm. I imagined that the maker of the universal module would produce 10,000 units in a factory at a really good price and other people would sell (or home-brew) hundreds of processor chips or memory cards to stick in them.

But, this is like a customizable complex module like the Doepfer and Tip-Top LCD-screen modules. This is also a little like the size and complexity of a Hertz Donut or Piston Honda. Sure, there's room for a variety of manufacturers and a variety of approaches.

More power to you technical whizzes for the universal hardware and lots of audio-processing plug-ins or uploads.

But, really, I like this just for the white knobs in combination with the retro brown knobs and the golden background. Style is what it all comes down to.

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Post by skrasms » Fri Feb 19, 2010 9:57 pm

My answer to the survey wasn't one of the options. I would choose "it depends."

I very much like the idea of interfacing modular synth data into a system that's easy and cheap for anyone to play around with like the Arduino.

However, I have a lot of questions about how far your implementation can be pushed. For example, I'll start with the ADC. Given that the A/D is 10 bits, covers a wide voltage span, and can be adjusted from +/-9V to +/-17V, I'm assuming there is no precision gain for handling pitch CV. Is that correct? In other words, micro-tuning pitch quantization stuff with this module seems to be off the table right now. The system won't have resolution better than about 17.6 millivolts, or 21 cents in musical terms.

Are you using the Atmega 1280's A/Ds? Looking at the Atmega 1280 datasheet, it says the max total sample rate of the A/D is 15 kHz. Because it's multiplexed, that number has to get divided by the number of channels, so a 6-input CV module can't sample inputs faster than 2.5kHz. Are you putting up with that, or using off-chip A/D converters to get around it?

The brain is the only module with a processor? So I can't get multiple CV input modules without also getting a bunch of brains? Also, won't a system with every module run slower than a system with only one or two?

The D/A is 16-bit monotonic, but its accuracy is only 12-bit. Have you looked into any others? What about the output sample rate?

An Arduino isn't powerful enough (as far as I know) to handle Ethernet traffic itself, so I'm assuming you're using an off-the-shelf Ethernet to serial or Ethernet to parallel chip. Do you have any specs for performance? The Arduino Ethernet implementations I've seen have generally been very slow for actual data throughput, and combined with a hefty protocol like OSC it seems like they could end up even slower than MIDI.

I'm curious as to what trade-offs you went with in designing this. Hopefully my questions aren't too intrusive. I'll definitely keep track of where this goes.

Also, what do you have against PWM? Don't hold low-quality implementations against the format itself :)

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Post by Veqtor » Sat Feb 20, 2010 10:35 am

I hope we can get it with custom panel-color schemes... I want mine in red.
Also, are you using the Atmega1280 or the Atmega1280P?
Why aren't you using the 1284P instead? It's 20 MIPS

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Post by __ag » Sat Feb 20, 2010 11:33 am

Hello all!!

this as been so overwhelming!!!
the feedback as been so great, i haven't done everything else but replying emails since yesterday!!
and only now i realized how this thread got so big!
thank you all for your comments, i'll look into them with deep attention and will make changes, integrate ideas, discuss options, etc with all of you!

sorry not to answer to everyone in detail right now, but i do want to go back to the soldering station and make this ready as fast as one human being can :)

there's some very pertinent comments that i'll answer in the next days, or use your questions and concerns to create a detailed FAQ on the website

but i don't want to end without some explanations, so briefly into each of the big questions:
ethernet is an option that's still in theory, i'm positive that i can implement it although still not sure how fast it will be!

bipolar voltages not supported yet, but i'm looking deeply into this!
as well as CV quantizations for oscillators tuning

than skrasms post hits the nail in the head!
i really have to document this very very well, processor speed is indeed something that affects the system work, so the more code in it the slower will be the microprocessor loop cycle, so for example very fast triangle generation will have a resultant wave that will look like a ladder and not smooth analog voltage, right now the system is looping at 5-15 milliseconds which i think is still quite fast ...
but to be very honest i really like the sound of that stepping triangle running at very fast speeds, so some of this system limitations i see them more as features!
i'll demonstrate all this in videos to be done very soon!

and i don't have anything against PWM, actually i love it but not for CV generation ;)
have you seen it on an oscilloscope? ;)

it's been some exhausting months working almost non stop in this, i've been holding my tongue about it, but now that it's out there and with the feedback that i'm getting it gave me an extra boost to wrap everything up fast fast fast!

so back to tinkering!!
keep bombing me with questions and emails, i'm very interested in anything you might have to say! good or bad!

for those of you who wanna be involved with it, resserve, or get direct emails about developments please send me an email through the form in the website, i'm creating a mailing list from there:

all the very best

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Post by slow_riot » Sun Feb 21, 2010 5:46 pm

this looks extremely promising.

i'm really attracted by the possiblities of analogue and computers, but there are certain problems that are really outside of my reach to solve.

I think this solution will definitely fill a amjor gap for me. I need to get my head around it all properly but atm I'm very interested in the capabilties of these modules.

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Post by Thonk Support » Mon Feb 22, 2010 1:49 pm

I'm very interested in this too.
Thonk - CLICK HERE - Modular Synth DIY + Eurorack Accessories Store

AS of October 2020 this account which used to go by the name of Monobass is now manned by various staff at Thonk.

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Post by Qmod » Wed Feb 24, 2010 6:14 am

funtykigs wrote:I'm very interested in this too.
I'm sold!!!

Been in contact with Andre since the first post... like many of us trolling around here.

Despite certain systemic limitations, this modular platform concept and Andre's commitment to development and product realisation is absolutely inspiring - 001, 002, 003, 004, 005 ordered.

Hopefully the brain and software can be used to program / hack the Arduino based rotating clock divider module and other cross platform Arduino variants.

The idea of the knob of infinite possibilites has become one step closer to reality

What an awesome year 2010 is shaping up to be for modular synths!


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