Raspberry Pi

[potul]

Hi,

Lately I've seen some interesting projects related to Guitar effects using the Raspberry Pi platform:

-Using guitarix http://ampbrownie.com/
-Using Pure Data  https://github.com/doitnowlabs/rpieffectbox, and a video http://www.youtube.com/watch?v=bLcW70tcBX8

Things are moving fast in this area... and I'm starting to be tempted to buy one Raspberry Pi to start playing with it... I like the idea of using PD to create fancy stuff, test it in my PC and then move it to the PI...

Mat

[azrael]

This is awesome! I've been trying to figure out what to do with my Raspberry Pi, think I may have found it!

[potul]

I ordered my raspberry pi last week... hopefully I will receive it in the next days and I'll start playing with it!

And.... I will need to find a cheap compatible usb soundcard.. I'll first try with the one I have at home in my PC and see if it works.

Mat

[doitnowlabs]

Potul, I think you'll love pure data for guitar effects. The possibilities are endless, literally! And just so you know, the Raspberry pi eLinux page has a list of compatible hardware, and it mentions the USB sound cards that work well with the pi and sound decent. Don't rule out cards that aren't listed there, though. Here's the link: http://elinux.org/RPi_VerifiedPeripherals#USB_Sound_Cards

Ben J., doitnowlabs

[ampbrownie]

I noticed this forum sending traffic to AmpBrownie, so I thought I would let you guys know that it's officially released and working.  I haven't made any videos of it in action yet, but I hope to get those out soon. 

By loading the setup script, and running through setup, you will have a killer little guitar effects rig in your raspberry Pi.  The easiest method of turning your Pi in to a stompbox

[Digital Larry]

Glad I stumbled across this AmpBrownie/Guitarix thread.  I do have a CubieBoard waiting for something to do and given that it is somewhat more powerful than a RasPi I am going to start with that.  The Guitarix Embedded Wiki targets a pcDuino and says it should also work OK on anything similar like a CubieBoard.  I'm not convinced that I DON'T want to use the built-in graphics of the CubieBoard for the UI instead of going headless and trying to control it from my Motorola Xoom (that thing has to be useful for something).  But I'll try headless first.

I'm not a metal high gain nut but I'm also concerned about noise creeping into the audio interface over USB power.

Was looking at one of the Akai EIE I/O (cute).  As it has a connection for external DC power.

Anyone had any experience with it?  It's only 16 bits, but who are we kidding here?

I figure it's either "get the thing so small that it will fit inside my existing amp" or "give up and make sure it's heavy enough so it doesn't fall off the table when it has a guitar cord connected to it".

Thanks,

DL

[aballen]

very cool stuff, and I have a few Rpis at my house.  Ordering the other bits now!

[potul]

I've been playing for some days now with my new Raspberry Pi and I'm amazed on this little thing. But... I'm in a dead end at the moment.

I can't get JACK to work properly with my usb soundcard.  I have a Behringer gutiarlink clone, and it works with aplay/arecord nicely, but as soon as I try to use JACK I get a naghty "digitally distorted" sound.
In order to be sure that the USB soundcard works well with Linux, I installed Debian in a PC and tried to install everything there. Works like a charm... I can run JACK, guitarix and Puredata with no issues. But no luck in my Pi.

I've followed all tips from http://wiki.linuxaudio.org/wiki/raspberrypi, but they did not help.
I've monitored the CPU usage and it looks ok (around 30%), so it doesn't seem to be a CPU power issue.

Any ideas on what else I can try? Anyone got a Behringer USB device to work on a Rpi?

[potul]

Nevermind.... this is Murphy's law.
30 minutes after posting my previous call for help... I could make it work
The key thing was forcing usb 1.1 ... I tried before but did not disconnect my keyboard/mouse and the system became unstable, so I undid it. Now I've tried without anything attached to the usb port other than the audio card, and I could make it work.
The issue is now that I have no keyboard/mouse, so I need to do everything via ssh.

My idea is to be able to run a headless pi with puredata patches I can create from my PC and copy them in the pi when I'm happy.

Still a lot of work to do, of course, but having the audio to work was a first step. Now I need to attach some kind of LCD and buttons, and probably code something in python or similar to make the whole thing work.

I'll keep on trying and let you know my progress.

[potul]

Well, I finally have something working.
My Pi is now upgraded with an LCD and some buttons, and it's able to run "headless" with some patches. I'm working at the moment to fine-tune the UI with the LCD, but I can already select patches and change parameters from the the LCD and buttons.

I sill have to fix some stability issues I have with jackd, ... sometimes is gets unstable and starts distorting after some runtime and I have to reset the buffer_size in order to get back to normal.

As soon as I can I will record a video and show you how it works

[Ice-9]

Great work Potul, looking forward to seeing how you get on with this.

[ampbrownie]

Hey guys, the video demo of AmpBrownie in action is available:  http://www.youtube.com/watch?v=PjM6rMWvnZE

I am very happy with how the sound has come out so far. Just great!

[Digital Larry]

That's cool.  I just wish there were a better solution for the audio interface!  I'd prefer to put the whole thing into some sort of box.

[slacker]

I stumbled across this addon sound card the other day http://www.element14.com/community/community/raspberry-pi/raspberry-pi-accessories/wolfson_pi might be a nice solution. The "buy now" link wasn't working for me so I've got no idea how much it costs. Unfortunately, I've got a rev 1 Pi so it's no use to me otherwise I'd probably get one to experiment with.

[Digital Larry]

Thanks for the link slacker.   

I read through some of the comments.  At this point getting driver support is still a matter of compiling and installing kernel mode drivers... well, as lovely of a way to spend an afternoon or three that might seem, I'm not too sure about it.  One other thing I'd still wonder about is the noise floor of such a thing, which you'll certainly encounter when you try some high gain modes with Guitarix.  Still, it's nice to see progress being made!  I got my first Pi (two?) years ago and OS image support is much better than when I started.

[Resynthesis]

I stumbled across this addon sound card the other day http://www.element14.com/community/community/raspberry-pi/raspberry-pi-accessories/wolfson_pi might be a nice solution. The "buy now" link wasn't working for me so I've got no idea how much it costs. Unfortunately, I've got a rev 1 Pi so it's no use to me otherwise I'd probably get one to experiment with.

£24

[Kipper4]

I be watching this to see how it develops. Just bought some holiday reading.
Raspberry pi for beginners..

[gasmask]

I know that it's really, really old topic, but I'm curious and I have few questions for those who made it.
1. Will it work on my RPi B+? There are some little differences between this model and classic B model.
2. Which one (shown on the first post) is easier and cheaper?
3. Where can I find whole schematic for the second method?

Oh, and of course.... is it really working in real-time?
I am new to this topic, I've never combined programming/scripting with analog circuits(just a few with lcd, buttons and RGB Led).  
Thanks for reply
gasmask

[slacker]

They will both work on a B+, the only difference that matters for these projects is that the B+ has a bigger GPIO connector but it's backwards compatible with older models so not a problem. The Ampbrownie is easier because it uses existing hardware so you just plug in all in, no soldering required. The second one is probably cheaper, I'm guessing the parts for it are less than the cost of the the Korg Nano controller used by the Ampbrownie.
The schematics for the second one are on the github page, I don't know what format they're in though, it doesn't say anywhere.

I don't know how real time they are, there will be some latency like with any software, some of it will depend on the USB soundcard used.

[gasmask]

I have made it
Ive chosen Pure Data. There is no latency... (maybe a few miliseconds, but you won't hear it).

Thanks for reply
gasmask