AudAVR (or Arduino for musicians)

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mrkva
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AudAVR (or Arduino for musicians)

Post by mrkva » Mon Jul 02, 2012 3:10 pm

AudAVR (codename)

Dear friends,

I would like to share a project idea I have for some time (and probably has been thought of by many of you as well - Electric druid, I am looking at you) and hear your responses, comments and criticism!

Little about me - my name is Jonas and I love modular synthesizers (obviously). I works as a performer/artist and study in Netherlands at Institute of Sonology. I am not engineer, but I love working as one for interesting projects. I programmed and designed circuits for bunch of artistic installations with Arduino code, but I also work in C, Supercollider, MaxMSP and others, most recently trying to figure out Asembly code. Here is my web for those interested: http://mrkva.ovecka.be

Idea of the project is to create universal and open design for utilizing AVR microcontrollers as various modular synth modules. One could say, "Arduino for musicians" - AVR controllers with combination of Arduino platform offers quite interesting possibilities for our musical purposes. By using DDS (Direct Digital Synthesis from filtered PWM signal as low cost option) or dedicated DAC chip with combination of 32kb of Atmega328 chip we are confronted with a lot of space to experiment and play.

After designing the board, the plan is to start designing our own musical software, which can be than easily transferred via USB right to the board. If one would get bored with his module, he/she could easily rearrange functions of pots/outputs/inputs (basically the whole module) by uploading new program to the chip.

Wiki with all the schematics, PCBs and codes will be available and open for collaboration. One of the ideas is to create a little code snippets which would allow you to combine your own module with ease. And by combining bunch of modules - create our own instrument.

There is no financial gain planned on this project - everything will be licensed with GNU/GPL and free for download. There will be possibly some professionally made available PCBs after prototyping, sold for the cost of the board + postage.
Main rules are to keep everything simple, open and as SMD-component-free as possible (so - easy to assemble).

Planned 'example' specs of low cost (DDS) module:
4 potentiometer / sensor inputs

2 'audio' inputs
2 trigger inputs

4 'audio' / cv / trigger outputs

2-digit display
4 RGB LEDs

The better-config module would have external 12-bit DAC chip, multiplexers (therefore more I/O) and possibly matrix display.

Possible uses I can think of (some I've even tried with Arduino): easy sensor-to-CV convertor (light, pressure, temperature, whatever you can think of!), random trigger generator, advanced tap-tempo, envelope generator, strange oscillator (gendy anyone?), random CV generator, weird LFO with all kinds of shapes and many more (waiting to be discovered by you!)

Since the whole project is open, I am now inviting you all to collaborate and discuss. Currently I am designing the schematic for the first low cost prototype (and waiting for the DAC chips for other prototype to arrive) - so if you feel like it, send me a PM, I can send you the Eagle files. Later on, I will make a wiki for this project and make the collaboration a bit easier.

Thank you for reading!
Last edited by mrkva on Mon Jul 02, 2012 5:58 pm, edited 5 times in total.
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cbm
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Post by cbm » Mon Jul 02, 2012 5:33 pm

Do you know about Ardcore?
http://20objects.com/ardcore/
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mrkva
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Post by mrkva » Mon Jul 02, 2012 5:54 pm

cbm wrote:Do you know about Ardcore?
http://20objects.com/ardcore/
Yes, it is a nice project - but I see some problems there.
For example, use of Arduino Nano isn't really necessary for this kind of project, and it is much cheaper to have just atmega chips there. I don't seem to find schematics and the whole project is a bit weirdly documented. No offense here, just saying it could be done a bit better and importantly - more open (I don't see licensing information there, assuming it is not open source).
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Post by darwingrosse » Mon Jul 02, 2012 8:18 pm

mrkva wrote:
cbm wrote:Do you know about Ardcore?
http://20objects.com/ardcore/
Yes, it is a nice project - but I see some problems there.
For example, use of Arduino Nano isn't really necessary for this kind of project, and it is much cheaper to have just atmega chips there. I don't seem to find schematics and the whole project is a bit weirdly documented. No offense here, just saying it could be done a bit better and importantly - more open (I don't see licensing information there, assuming it is not open source).
Well there are a lot of assumptions in there. Let's start with the "openness" question. All of the software has a Creative Commons Att-NonC license, which is about as open as I can imagine being. Should I have allowed commercial use of the code? I dunno - maybe that makes me a Bad Man.

As for the weirdness of the documentation, I don't really know what to say. Without any support, a project like this goes nowhere. I decided to focus on code creation over documentation, so I created 20+ different sketches rather than writing a programmer's manual. Maybe a poor decision, but that's the one I made.

Note that there is no restriction to creating the hardware and using the software - only that it isn't acceptable to profit from the code itself. Currently, the SnazzyFX ArdCore implementation is using all that code without limit, and we are getting some interesting additions from the user base.

As for the hardware, there isn't much licensing to be done. Everything is built off the Arduino core, meaning that I'm just buffering levels for a modular synthesis chain, and I tie 8 pins together for through a DAC for an analog output. No magic there.

I didn't put up schematics because I'm using a B.S. schematic and board layout software package that won't let me export to anything usable. I've provided most of the information necessary to create a board; adding a few bits and bobs is all that is necessary to create a board. We, in fact, sell the bare boards for DIY fans, and try to provide as much information as possible for builders.

Does replacing the Arduino with Atmega chips really reduce the cost? If you price all the components (including the USB programmer interface) as one-off costs for SDIY folks, it isn't much of a difference. And, using the through-hole Atmega means that you will only have 6 analog inputs rather than 8, or you are using a different chip that won't necessarily work directly. Using the Nano also means that we would be able to take advantage of any improved Nano implementation that might be available in the future (as a user-installable option).

There's another part of this, though, that I find discouraging. I take full advantage of the Arduino toolset to make it easy for people to program on the Ardcore system. By purchasing the Arduino Nano for inclusion on the device, I actually help support the environment that the module is based upon. So that is a decision we made consciously.

So that's my story, and I'm stickin' to it!
[ddg]

Art+Music+Technology podcast:
http://artmusictech.libsyn.com/

Modular Synth Mastery books:
http://20objects.com

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Post by mrkva » Mon Jul 02, 2012 8:59 pm

darwingrosse
Hey man,

I didn't meant to offend you or anything, I clearly overlooked some parts. But since the schematic is not available, nor PCB layout, it kind of ruins the openness of the project for me. On the other hand, the code is nicely documented and I love that.

Regarding Arduino Nano - it is more expensive in my opinion, Atmega328 (okay - 2 less inputs, but that can be fixed by multiplexing) costs around 3-4 euros, Arduino Nano costs 20+ (afaik). For all the modules one would have, just one programmer would be enough and that costs around 15 $ ( http://www.sparkfun.com/products/9825 ).

And with V-USB for AVR there is a way to achieve a state completely without any programmer, so all you're left with is cost of the chip + some small things like crystal, caps, usb connector.

It would be great if we could join our efforts and share the knowledge to think of even better modules, don't you think? Or you don't see a room for improvement?

Regards, Jonas
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Post by stk » Mon Jul 02, 2012 9:36 pm

I'm interested, done a fair bit or Arduino coding in the past year or so (last thing I go working was a 3x8 channel cv/gate sequencer with a BCR2000 as a 2-way user interface).

I've looked into the Ardcore but it doesn't have enough CV outputs for me.
I want at least 4, preferably more (ideally 4x 12bit CV, 4x digital gate) but haven't had the time or electronics knowhow to have a go at connecting up DACs.

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Post by surgesg » Mon Jul 02, 2012 10:39 pm

From my own experience with the Atmega328, I'd be more excited to see something faster and with more memory used.

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Post by mrkva » Tue Jul 03, 2012 4:37 am

surgesg wrote:From my own experience with the Atmega328, I'd be more excited to see something faster and with more memory used.
Do you have something particular in my mind? Can you elaborate on when and why wasn't Atmega sufficient?
The thing I like about Atmegas is of course the Arduino IDE, very easy to use for everyone, therefore more open for innovation.
But if you think there is something better that could be used, please let me know - I know there are some ARM processors, but that is all SMD stuff which can be hardy assembled by common folk at home.
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Post by surgesg » Tue Jul 03, 2012 9:56 am

something fast enough to do signal processing with a reasonable sample rate would be great.

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Post by Tombola » Tue Jul 03, 2012 10:08 am

I've used Arduino a bit in diy modules - originally used bare AT328 chips, but now using Nanos - They're around £12 for a clone on ebay, and nice to use on breadbards, with the built in USB.

I really enjoy Arduino, it's taught me so much, and like Greg, my dream would be Arduino for DSP. A cheap (<£50), well documented, community-led way to get into it.

I guess I could get a Z-Dsp and Numberz and some cards, but it's a pretty big investment.
Last edited by Tombola on Wed Jul 04, 2012 7:25 am, edited 1 time in total.

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Post by executiveBlaster » Tue Jul 03, 2012 12:41 pm

good points about the atmega328 being a little wimpy. I would love to be part of an effort to break into atmels beefier lines, ones with qtouch and dacs built in and all that loveliness.

arduino due is coming out soon, too. 32 bit, jamzilla.

that being said, the 328 can totally handle an 8ch dac and a good bit of code to tell it what to do. Right now I'm using the DAC7578 from TI, and it totally rocks. All of the headache of getting them to talk together is an issue of yestermonth! so anyone who wants to can nab one of those, nab a schmart-board tssop adapter, and an atmel328 (easiest if you get chips with the arduino bootloader...) and blam, 8 channels of highly expressive (as expressive as your code!) voltage outputs.

I'm happy to share my code and experiences and whateva.

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Post by mOBiTh » Tue Jul 03, 2012 1:13 pm

i want this:

http://www.altera.com/products/devkits/ ... 3-dsp.html

comes with matlab/simulink (my favourite ide)

it's not a completely horrendous price really although god knows when I'd actually find time to make the most out of it

cylonix cyclebox uses the altera cyclone FPGA

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Post by J3RK » Tue Jul 03, 2012 2:31 pm

mOBiTh wrote:i want this:

http://www.altera.com/products/devkits/ ... 3-dsp.html

comes with matlab/simulink (my favourite ide)

it's not a completely horrendous price really although god knows when I'd actually find time to make the most out of it

cylonix cyclebox uses the altera cyclone FPGA
Me too! I want to grab a couple of those DE0 Nano eval boards. A good friend of mine does quite a bit with FPGA, so I've got someone to bounce things off of.

The XMega chips look pretty good for the Atmel side of things too. I picked up a few of them, and a Dragon programmer. Haven't gotten to it yet though. I'm working on my first AVR design right now with a friend, and will see how that goes before plunging into the rest of this. :mrgreen: :ripbanana:

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Post by stk » Tue Jul 03, 2012 8:23 pm

executiveBlaster wrote: that being said, the 328 can totally handle an 8ch dac and a good bit of code to tell it what to do. Right now I'm using the DAC7578 from TI, and it totally rocks. All of the headache of getting them to talk together is an issue of yestermonth! so anyone who wants to can nab one of those, nab a schmart-board tssop adapter, and an atmel328 (easiest if you get chips with the arduino bootloader...) and blam, 8 channels of highly expressive (as expressive as your code!) voltage outputs.

I'm happy to share my code and experiences and whateva.
..Can you please translate that into non-hardware-guy language?
I'm an experienced coder but pretty green at hardware DIY, would love to get arduiono + 8 chans of dac up and running.
Thanks :)

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Post by surgesg » Tue Jul 03, 2012 8:29 pm

i've made something similar to the 8-channel dac idea with my usb-octomod project:

http://gregsurges.com/circuitry/usb-octomod

quibbling about hardware power aside, i think this is a great idea

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Post by th0mas » Tue Jul 03, 2012 9:42 pm

Once availability issues are sorted I feel like this is an excellent role for the raspberry pi. Lots of processing power, not a weird DSP, super cheap.

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Post by clorax hurd » Wed Jul 04, 2012 1:56 am

surgesg wrote:something fast enough to do signal processing with a reasonable sample rate would be great.
I think, that having something programmable, just incapable of DSP would be very cool for logic purposes. The prices of logic modules are just crazy. Check the prices of Intellijel flip-flip, spock, plog or Doepfer A-166. and check what they are capable of. Patching anything bit more complex with these would cost you fortune and take quite a lot of space in case. I would much prefer, to have something cheaper and easily programmable.

+ this could be also good for CV processing. even 777Hz sample rate would be still good enough for such purpose.

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Post by JJ » Wed Jul 04, 2012 3:49 am

How about Copperduino for connetivity + The Raspberry Pi for power?

http://www.copperduino.com/

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Post by lightworks » Wed Jul 04, 2012 4:00 am

stk wrote:
executiveBlaster wrote: would love to get arduiono + 8 chans of dac up and running.
Thanks :)
maybe this?
http://www.addacsystem.com/products/ADDAC000%20Series
8 channels with a 16 bits resolutions dac :tu:

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Post by mrkva » Wed Jul 04, 2012 5:48 am

Yes, regarding Raspberry Pi, I was also thinking about making dedicated 'musician' version - some small soundcard (USB) and Supercollider/Chuck code. Maybe with some Arduino for connecting pots, faders, CV inputs. Make a box solution, where one would just upload his patches with ethernet and it would start them automatically when turned on :) Imagine - having your favorite synthesis in a little box, no display, just pots and LEDs.
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Post by stk » Wed Jul 04, 2012 7:19 am

lightworks wrote: maybe this?
http://www.addacsystem.com/products/ADDAC000%20Series
8 channels with a 16 bits resolutions dac :tu:
370 euros.... No thanks

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Post by mOBiTh » Wed Jul 04, 2012 9:46 am

J3RK wrote:
mOBiTh wrote:i want this:

http://www.altera.com/products/devkits/ ... 3-dsp.html

comes with matlab/simulink (my favourite ide)

it's not a completely horrendous price really although god knows when I'd actually find time to make the most out of it

cylonix cyclebox uses the altera cyclone FPGA
Me too! I want to grab a couple of those DE0 Nano eval boards. A good friend of mine does quite a bit with FPGA, so I've got someone to bounce things off of.

The XMega chips look pretty good for the Atmel side of things too. I picked up a few of them, and a Dragon programmer. Haven't gotten to it yet though. I'm working on my first AVR design right now with a friend, and will see how that goes before plunging into the rest of this. :mrgreen: :ripbanana:
ah cool, yeh that's the cylonix processor board (DE0 nano) nice one 8_)

I'll get my head around that first, although i really need to get a midi/arduino project finished first for a mate. need more days in the week...

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Post by mrkva » Wed Jul 04, 2012 12:59 pm

clorax hurd wrote:
surgesg wrote:something fast enough to do signal processing with a reasonable sample rate would be great.
I think, that having something programmable, just incapable of DSP would be very cool for logic purposes. The prices of logic modules are just crazy. Check the prices of Intellijel flip-flip, spock, plog or Doepfer A-166. and check what they are capable of. Patching anything bit more complex with these would cost you fortune and take quite a lot of space in case. I would much prefer, to have something cheaper and easily programmable.

+ this could be also good for CV processing. even 777Hz sample rate would be still good enough for such purpose.
indeed, logic modules was something i had in mind as well - not very hard to program (even more complicated ones) and also not hard to make on the hardware side...
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Post by Veqtor » Wed Jul 04, 2012 6:18 pm

Someone should make a arduino-esque board around a 2in/2out dspic!

If it came with a simple IDE with a predefined sketch with a process-loop, then I think a lot of people would be able to quickly create dsp modules!

It would be perfect for a lot of people!

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Post by mrkva » Wed Jul 04, 2012 6:20 pm

Veqtor wrote:Someone should make a arduino-esque board around a 2in/2out dspic!

If it came with a simple IDE with a predefined sketch with a process-loop, then I think a lot of people would be able to quickly create dsp modules!

It would be perfect for a lot of people!
That is indeed one of the plans with this project. Easy to use, not expensive boards with open design (open for improvements!)
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