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DIY Stompboxes => Digital & DSP => Topic started by: potul on May 21, 2013, 11:01:57 AM

Title: Raspberry Pi
Post by: potul on May 21, 2013, 11:01:57 AM
Hi,

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

-Using guitarix http://ampbrownie.com/ (http://ampbrownie.com/)
-Using Pure Data  https://github.com/doitnowlabs/rpieffectbox (https://github.com/doitnowlabs/rpieffectbox), and a video http://www.youtube.com/watch?v=bLcW70tcBX8 (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
Title: Re: Raspberry Pi
Post by: azrael on May 25, 2013, 01:06:42 PM
This is awesome! I've been trying to figure out what to do with my Raspberry Pi, think I may have found it!
Title: Re: Raspberry Pi
Post by: potul on May 26, 2013, 03:18:24 AM
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
Title: Re: Raspberry Pi
Post by: doitnowlabs on June 07, 2013, 06:12:31 PM
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
Title: Re: Raspberry Pi
Post by: ampbrownie on June 17, 2013, 02:22:48 PM
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 :)
Title: Re: Raspberry Pi
Post by: Digital Larry on June 27, 2013, 03:04:43 PM
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  (http://sourceforge.net/apps/mediawiki/guitarix/index.php?title=Guitarix_Embedded_/_ARM_SoC) 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 (http://www.akaipro.com/eie) (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
Title: Re: Raspberry Pi
Post by: aballen on August 22, 2013, 01:30:27 PM
very cool stuff, and I have a few Rpis at my house.  Ordering the other bits now!
Title: Re: Raspberry Pi
Post by: potul on October 05, 2013, 04:03:14 AM
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 (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?



Title: Re: Raspberry Pi
Post by: potul on October 05, 2013, 12:30:59 PM
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.
Title: Re: Raspberry Pi
Post by: potul on October 25, 2013, 04:11:29 AM
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
Title: Re: Raspberry Pi
Post by: Ice-9 on October 29, 2013, 07:37:26 PM
Great work Potul, looking forward to seeing how you get on with this.
Title: Re: Raspberry Pi
Post by: ampbrownie on February 17, 2014, 02:43:07 PM
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!
Title: Re: Raspberry Pi
Post by: Digital Larry on February 23, 2014, 12:35:01 PM
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.
Title: Re: Raspberry Pi
Post by: slacker on February 23, 2014, 01:05:17 PM
I stumbled across this addon sound card the other day http://www.element14.com/community/community/raspberry-pi/raspberry-pi-accessories/wolfson_pi (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.
Title: Re: Raspberry Pi
Post by: Digital Larry on February 23, 2014, 01:30:31 PM
Thanks for the link slacker.   ;D

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.
Title: Re: Raspberry Pi
Post by: Resynthesis on February 23, 2014, 07:46:34 PM
Quote from: slacker on February 23, 2014, 01:05:17 PM
I stumbled across this addon sound card the other day http://www.element14.com/community/community/raspberry-pi/raspberry-pi-accessories/wolfson_pi (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
Title: Re: Raspberry Pi
Post by: Kipper4 on March 08, 2014, 03:37:26 PM
I be watching this to see how it develops. Just bought some holiday reading.
Raspberry pi for beginners..
Title: Re: Raspberry Pi
Post by: gasmask on December 18, 2014, 02:15:16 PM
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).  :icon_confused:
Thanks for reply
gasmask
Title: Re: Raspberry Pi
Post by: slacker on December 21, 2014, 08:26:47 AM
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.
Title: Re: Raspberry Pi
Post by: gasmask on December 23, 2014, 06:09:54 PM
I have made it :)
Ive chosen Pure Data. There is no latency... (maybe a few miliseconds, but you won't hear it).
:icon_biggrin:
Thanks for reply
gasmask
Title: Re: Raspberry Pi
Post by: Digital Larry on December 24, 2014, 01:26:15 AM
So do you have it connected to a monitor or are you using VNC?
Title: Re: Raspberry Pi
Post by: gasmask on January 04, 2015, 05:35:56 AM
VNC, but when my wifi card is plugged in, the sound isn't clear. I mean there are a lot of clicks and pops... when I use my monitor, mouse and keyboard, it has really really amazing sound. When acoustic guitar is plugged in, it sounds like 'studio sound' (clear and wonderful), but with my electric guitar there is a tone suck...
but still, I am impressed.
:)
Title: Re: Raspberry Pi
Post by: Digital Larry on January 04, 2015, 06:34:36 AM
Probably wants a preamp or buffer on the input, doubt the codec card has 1 M input impedance.  Too bad about the wifi causing problems.  It'd be great to be able to use an iPad or Android tablet for the UI.
Title: Re: Raspberry Pi
Post by: gasmask on January 04, 2015, 11:05:25 AM
Exactly, now I am just curious how to use PureData GUI but without using VNC. Maybe little lcd screen with mouse and keyboard in a pedalboard? ;)
Title: Re: Raspberry Pi
Post by: free electron on January 04, 2015, 11:12:39 AM
Quote from: gasmask on January 04, 2015, 11:05:25 AM
Maybe little lcd screen with mouse and keyboard in a pedalboard? ;)
Full QWERTY keyboard with momentary footswitches, that would be something! ;)
Title: Re: Raspberry Pi
Post by: gasmask on January 04, 2015, 11:20:07 AM
Or little (4-6 inch) touchscreen... and configuration to launch in gui mode :)
Title: Re: Raspberry Pi
Post by: Digital Larry on January 04, 2015, 11:22:15 AM
How about an Oculus Rift, with a GoPro overlay so you can see what you're doing?
Title: Re: Raspberry Pi
Post by: gasmask on January 04, 2015, 12:57:04 PM
hmmm... Very interesting. Will OculusRift cooperate with Debian? XD
but seriously, I still do not know how to solve the problem with gui...
Anyone? Any ideas? ???
Title: Re: Raspberry Pi
Post by: free electron on January 04, 2015, 01:39:39 PM
Like you said: small TFT + touch screen?
Like this one:
http://www.sainsmart.com/7-inch-tft-lcd-monitor-for-raspberry-pi-touch-screen-driver-board-hdmi-vga-2av.html
Title: Re: Raspberry Pi
Post by: potul on January 22, 2015, 09:11:32 AM
What I've done is:

-Use Puredata without GUI
-add an LCD + pushbuttons shield and use it to change presets and tweak parameters via a python script

Of course, when creating patches I need to use the gui, but once I'm done with it, I can access them like a preset from the keypad.
Title: Re: Raspberry Pi
Post by: sonic66 on June 11, 2015, 02:02:25 AM
The usb sound card is it mic or line level? If you wanted to run it between the guitar and another pedal or amp wouldn't you need a preamp on the input and a pad on the output?
Title: Re: Raspberry Pi
Post by: rotylee on June 11, 2015, 02:44:43 PM
http://www.samplerbox.org/home
new thread?

Features

    Drop'n'play sampler: drop .WAV samples on the SD card, and play!
    Open source / open hardware
    Raspberry Pi computer inside!
    Cheap: < 99€ to build it
    Boot time: 8 seconds
    Polyphony: more than 128 voices
    Latency: 11,6 ms
    Memory: can load sample-sets up to 1 GB

Title: Re: Raspberry Pi
Post by: vigilante397 on June 11, 2015, 05:59:40 PM
I'm not sure how I never saw this thread before, but it excites me greatly.