Anyone done audio processing with C.H.I.P


Hi all,
I got the chip as a gift and I am interested in unlocking it’s potential.
As a musician, I am really interested in signal processing, and I was wondering if anyone had used the Chip as a reverb or eq on an audio signal and how they went about it. Likewise if you have any ideas about implementation I’d be greatly interested in that as well.

[SOLVED] JACK audio server doesn't sound

Hi Captain Klark!
This project may be up your alley:
C.H.I.P. MIDI Arpeggiating Synth


You can run PD for easy DSP. sudo apt-get install puredata Other software/languages worth investigating:

  • Faust DSP
  • Supercollider
  • Chuck


I tried installing supercollider and the IDE installed but I get an error documented here:

anyone else have luck with this? I tried supercollider and supercollider-dev


apt-get install chuck
works for me - and I am able to run .ck files using
I hear sounds but the audio is very distorted. Does anyone else get similar results?
aplay test.wav
has much less static but still a 60hz buzz. So I think the problem might be with the default settings in chuck.


Hi Folks,

I got my favorite linux sound programming language working on CHIP, chuck: tonight - and after many different compiles and poor results with alsa using jack2 and compiling chuck for jack with 1.3.5 (chimera) worked beautifully. It’s a little tricky to follow so I thought I would document it here in case I need to setup another chip and if there is anyone else out there with obscure interest in this language. (it’s quite powerful and easier to understand than supercollider - also easier to run from the command-line).

###Installing and running chuck on C.H.I.P

make sure you have the proper build tools installed

sudo apt-get install flex bison````

lib requirements for jackd2 and compiling chuck
````sudo apt-get install jackd2
sudo apt-get install libjack-jackd2-dev
sudo apt-get install libsndfile1-dev````

follow directions at:
cd chuck-x.x.x.x/src/
make   #to see options
make linux-jack
make install````

to become superuser
````sudo su ````

export path to the dbus process for jackd
````export DBUS_SESSION_BUS_ADDRESS=unix:path=/run/dbus/system_bus_socket````

modify settings in /etc/dbus-1/system.conf by adding this at the end (you will need to be su and use nano)
````<policy user="root">
     <allow own="org.freedesktop.ReserveDevice1.Audio0"/>

Open a separate terminal window to monitor Jackd. You may have to restart the CHIP to have the config settings take effect. 
runing jack may require root permissions, I learned a lot from sites like this:
The first time I ran chuck it did not establish a connection so I looked around the internet and tried --sync or -S and thats when I heard undistorted sound for the first time. 

````sudo su 
jackd -d alsa -S````

Go to the chuck examples directory: 
````cd /usr/share/doc/chuck/examples
chuck ```

And you should hear glorious clear sound (I hope). Ping me if you try this and get stuck. 


Install Jack2 sound server on Pocketchip
Sonic Pi on the CHIP?

Can anyone tell me if it’s possible to get access to GPIO data using chuck or pure-data?


@sethhunter seems to be the expert about this language! I never heard of it, but it should be possible to trigger some bash commands and get the feedback?


I’m using pure data on C.H.I.P. with a USB audio card and I just tell pd which card to use on startup, my guess would be to force Jack or Alsa to consider the GPIO pins as another device and run pd with appropriate arguments.


In my experience (after trying both) PD has been more reliable for audio experiments than Chuck - its more actively maintained and does not require Jack.


I’m looking into it. So far OpenAL with either Java or Free Pascal, and making an ncurses based GUI. :smiley: look very feasible. Making a little program addition to route MIDI over the USB OTG serial or maybe a regular MIDI on the USB, and that should do the trick. This would reduce resources spent on graphics, and obtain almost the best signal processing speed without going OpenGL/CL. In some way the difficult task at present is the decisions on the UI/UX. I thought maybe an alphabet control select, up/down change, and left/right to set the up/down rate. Ummm …


i wonder what its like if we compiled ck for alsa. you chose jack cuz manually compiled chuck(4alsa) was also not good enough? its been a while since i compiled ck for my slackware machine :slight_smile:


I get “ALSA output error (snd_pcm_open): Device or resource busy” when turning on DSP computation in PD;
You or somebody else encountered this also and found a solution? :confused:


Mmm… somehow PocketCHIP works with my Focusrite Scarlett 2i2; That’s something! :stuck_out_tongue:


did you ever get pd up and running withouit use of a soundcard


i meant a usb soundcard


Never tried again. I am using a “3D SOUND” usb sound card… (easy to carry around) :slight_smile: