Raspberry Pi 2

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i2productions
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Raspberry Pi 2

Postby i2productions » Mon Feb 02, 2015 3:51 pm

http://www.raspberrypi.org/products/raspberry-pi-2-model-b/

I had big dreams and high expectation for the first Rpi as a small audio DSP. All the projects that have tried this have either failed or had limited success. This new one, at the same $35 price tag might finally have the bare minimum or horsepower to get the job done. Switching up to ARM v7 will open up a wider variety of OS. Can't wait to see what happens with it!

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danboid
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Re: Raspberry Pi 2

Postby danboid » Wed Feb 04, 2015 10:16 am

I recently bought a BananaPi which is a much better spec for me for the same price. Having SATA2 makes a big difference vs a USB2 - ~100MB/s for a SATA drive vs ~20MB/s for USB2. Gig ethernet is another big plus over the Pi. I've not had chance to try JACK on it yet but thats not what I bought it for but I have got both HW accelerated Full HD video (h264 under mplayer/smplayer) playback as well as OGLES2 working on it.

There is also the Banana Pro which includes onboard wifi for another £10 or the Cubietruck if you're will to pay 2x for another gig of RAM and a few more ports.
Are you new to Linux Audio? This manual explains how to install KXStudio, set up and use JACK, mimimize latency, lists the best Linux AV apps and much more all in a concise and easy to understand format.

http://wiki.linuxaudio.org/wiki/kxstudio_manual

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Re: Raspberry Pi 2

Postby jtode » Fri Feb 06, 2015 8:50 pm

The stock Pi has horrid sound - 11 bit, I read the other day - and only works with ALSA because of some peculiarity of the architecture. I believe the same applies to the new model.

However, there are a few cheap addon boards that connect straight to the I2S bus and give whatever format you need, and those look like very good prospects for some awesome homebrew devices with the new one, Jack support or no.

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Re: Raspberry Pi 2

Postby raboof » Fri Feb 06, 2015 10:39 pm

jtode wrote:The stock Pi has horrid sound - 11 bit, I read the other day

Yeah, I wouldn't expect much from the onboard audio

jtode wrote:However, there are a few cheap addon boards that connect straight to the I2S bus and give whatever format you need, and those look like very good prospects for some awesome homebrew devices with the new one, Jack support or no

Do you have experience with any? How do they compare to just plugging in a regular USB sound card?

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Re: Raspberry Pi 2

Postby i2productions » Sat Feb 14, 2015 8:43 pm

jtode wrote:The stock Pi has horrid sound - 11 bit, I read the other day


Yes, the onboard audio is totally unsuitable for pro audio work, however many USB cards work very well. In the early days of the Pi I was able to get Ardour to work with an Lexicon Omega. I wouldn't do anything crazy with it, but it could make a decent 4 track digital recorder!

danboid wrote:I recently bought a BananaPi which is a much better spec for me for the same price.


I hadn't seen this product. Just looked around for it. Looks like it's pretty much the Pi2 with a SATA connector, except the pi2 is a quadcore A7 as opposed to the dualcore in the banana. Pretty cool none the less!

Hopefully we see some cool audio projects coming out of these cheap little boards soon! My idea is a build a small board into a guitar or bass with a small touch screen(http://www.amazon.com/Adafruit-83-15684-PiTFT-Mini-LCD/dp/B00JFJJTM2/ref=sr_1_14?s=electronics&ie=UTF8&qid=1423946563&sr=1-14&keywords=raspberry+pi+touchscreen) embedded that can run guitarix and/or rakarrack. But the headless designs going so far are definitely not suitable. Can't wait to get my hands on one of these to give it a try!

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Re: Raspberry Pi 2

Postby tramp » Sun Feb 15, 2015 4:46 am

i2productions wrote:Hopefully we see some cool audio projects coming out of these cheap little boards soon! My idea is a build a small board into a guitar or bass with a small touch screen(http://www.amazon.com/Adafruit-83-15684 ... ouchscreen) embedded that can run guitarix and/or rakarrack. But the headless designs going so far are definitely not suitable. Can't wait to get my hands on one of these to give it a try!


For guitarix, you can run it headless, controlled by midi or the GPIO.
And there is also a web-based interface which is designed specially for small touch-screen devices.

A bit outdated:
http://sourceforge.net/p/guitarix/wiki/ ... _-ARM_SoC/

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Re: Raspberry Pi 2

Postby i2productions » Sun Feb 15, 2015 3:56 pm

Headless would be pretty worthless for the application I'm talking about. I want something you can control right from the instrument itself with no external input. The pi2 should have the horsepower to get the job done. I'll be ordering 1 sometime in the next month.

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Re: Raspberry Pi 2

Postby tramp » Sun Feb 15, 2015 5:37 pm

i2productions wrote:Headless would be pretty worthless for the application I'm talking about. I want something you can control right from the instrument itself with no external input. The pi2 should have the horsepower to get the job done. I'll be ordering 1 sometime in the next month.


Most usual desktop interfaces (GUI) will be useless on such 2.8" LCD displays to as they aren’t touch sensitive and didn't fit in the screen. At least that is thru for guitarix. Therefore the web-interface is made. it is touch-sensitive, and designed special for small displays like the one your link above shows.
Note, that you just need to run "localhost" (no wifi-dongle) on your device, to run the web-interface on the same device then guitarix runs, so, I guess headless + web-interface comes closer to your goal then you imagine.
I would consider to add a foot-switch (pedal) anyway, even if you didn't strictly need it to control your app, as it is often more comfortable then only a little screen on the guitar body.
Have you ever tried the preset Pick Mode in guitarix?
http://sourceforge.net/p/guitarix/wiki/ ... -pick-mode

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Re: Raspberry Pi 2

Postby miodek1987 » Wed Jun 03, 2015 9:14 am

Just bought a Rasperry Pi and I'm hungry for all info about it.

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Re: Raspberry Pi 2

Postby PJMCambs » Wed Jun 03, 2015 11:42 pm

Hi guys, I'm pretty new to the whole Linux & RPi arena and have recently purchased a couple to try and make a drum module to trigger drum samples from, but would also love to try the guitar rig project too, looks like fun.

I've bought 3 or 4 different boards to do some tests with various input methods to see which works best for my needs, but am struggling with getting setup with software prior to making any analogue inputs available.

I thought it would make sense to get the software side of things working before trying to adding any potential issues with analogue inputs from the likes of ADS1115 ADC. So I got a USB sound card to improve the sound quality, as I read this is the best solution and I figured I would connect a USB piano keyboard to the RPi to sort out the midi signals are all okay and trigger some drum samples during the testing phase.

Q: Do any of you have a standard set of tools you install/use to check stuff like audio and midi setup?

I've not had much luck with ALSA, JACK or dumkv1 yet, but will keep searching for more guides. Any tips would be greatly appreciated.
Cheers
Phill

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Re: Raspberry Pi 2

Postby Frank Carvalho » Fri Dec 18, 2015 3:09 pm

I've not had much luck with ALSA, JACK or dumkv1 yet, but will keep searching for more guides. Any tips would be greatly appreciated.


I finally decided to have a look at using the Pi2 for music. I have installed Raspbian for maximum compatibility. And I am happy to say, that I had absolutely no trouble getting my USB M-Audio Quattro to work with it, following the same procedure I described in https://linuxmusicians.com/viewtopic.php?f=6&t=13776, and I am now listening to playback routed from in to out at 48kHz, 24bit through Jack with a latency of 21ms. I also installed qjackctl with no trouble, and had it work with the Quattro configuration straight away, as I had also copied the .asoundrc. The Pi2 is not even remotely stressed by running Jack, with CPU usage at around 1%, which is promising.

Now things start to get more difficult. I installed Audacity, for a simple starter to prove its record and playback capabilities, but it seems that Audacity does not see the Jack server. Only ALSA is selectable for in and out? I have never seen Audacity fail in registering the backend. So I have to install some other app just to test if I can connect to Jack from other programs.

Edit: Nope. I just had to configure the quattro by the name "(Default)", and then it became visible to Audacity.

I then tried (ambitiously) to add the kxstudio repos just to see how far I would get. Well, after manually updating libc6 to version 1.19 for armhf, and a couple of other things, I was able to add the kxstudio-repos_9.2.2~kxstudio1_all.deb to the system. However (as one might expect) dependencies are broken, and lots of applications don't show up in the package manager. So I guess have to find and install, and possibly compile, the different packages myself.

I would like to try out Guitarix on the Pi2, but following the link provided by Tramp, it does not look like an entirely easy task to get going. I will write if I succeed doing this.

/Frank
Vox, Selmer, Yamaha and Leslie amplifiers. Rickenbacker, Epiphone, Ibanez, Washburn, Segovia, Yamaha and Fender guitars. Hammond, Moog, Roland, Korg, Yamaha, Crumar, Ensoniq and Mellotron keyboards. Xubuntu+KXStudio recording setup.

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tramp
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Re: Raspberry Pi 2

Postby tramp » Sat Dec 19, 2015 2:04 pm

Frank Carvalho wrote:I would like to try out Guitarix on the Pi2, but following the link provided by Tramp, it does not look like an entirely easy task to get going. I will write if I succeed doing this.


You could also try guitarix direct from the Raspbian repros.
http://ftp.jaist.ac.jp/raspbian/pool/main/g/guitarix/
(not the latest and greatest version, but still the last version available in debian for now)

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Re: Raspberry Pi 2

Postby Frank Carvalho » Sat Dec 19, 2015 5:21 pm

You could also try guitarix direct from the Raspbian repros.


Which is exactly what I've been doing since yesterday! :D It installs and runs, and I was even able to set up a chain with an AC15 model, overdrive, 2x12 cab sim and stereo echo which sounds really, really nice. (Andy Latimer style sound)

I am also glad you chipped in Tramp, as I have a question for you. I would like to try to run guitarix headless, but it seems there is no command line option to do so. How do I get it to start headless? Do I have to recompile with a special flag?

I also miss the latest and greatest additions, and not least the revised fuzz plugins, which I would really love to have available. So in any case, is it possible to compile the latest version of guitarix for ARM, and if so then how? (Any plans to make a repos available with the newest stuff compiled for ARM perhaps?)

My immediate problem though is with the latency. With the USB Quattro, I can run Jack at 48kHz/24 bit with buffer size 1024 without xruns, but latency is 42ms, which is unacceptable for guitar. I can run with buffer size 512 and 3 periods, but 512 and 2 periods and downward doesn't work so far. It starts but fails in connecting or has terrible digital noise if it does. Tried soft mode, but I can't get the parameters further down. And BTW, I notice that Jack starts in real-time mode, but I don't think the standard Raspbian kernel is an rt-kernel?

So now I need to tweak something to get latency down. Suggestions are welcome. I know the linuxaudio-wiki has a page full of tweaks for the RPi2.

/Frank
Vox, Selmer, Yamaha and Leslie amplifiers. Rickenbacker, Epiphone, Ibanez, Washburn, Segovia, Yamaha and Fender guitars. Hammond, Moog, Roland, Korg, Yamaha, Crumar, Ensoniq and Mellotron keyboards. Xubuntu+KXStudio recording setup.

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Re: Raspberry Pi 2

Postby tramp » Mon Dec 21, 2015 7:09 am

Frank Carvalho wrote:I am also glad you chipped in Tramp, as I have a question for you. I would like to try to run guitarix headless, but it seems there is no command line option to do so. How do I get it to start headless? Do I have to recompile with a special flag?


The command line flag is -N or --nogui
No special compile flag is needed. We've implemented the nogui option in version 0.28.0, so if you've a older version installed it may be missed.
Frank Carvalho wrote:I also miss the latest and greatest additions, and not least the revised fuzz plugins, which I would really love to have available. So in any case, is it possible to compile the latest version of guitarix for ARM, and if so then how? (Any plans to make a repos available with the newest stuff compiled for ARM perhaps?)

The latest version of guitarix just hit debain/sid today, usually it takes 10 days to move forward to testing. Then you could use guitarix directly from the debian repros for armhf.
I'm myself wouldn't distribute binary's, I distribute source code. :)
Some hints for building guitarix for the rpi, you'll find in the guitarix forum in the embedded section:
http://guitarix.sourceforge.net/forum/v ... m.php?f=14

Frank Carvalho wrote:So now I need to tweak something to get latency down. Suggestions are welcome. I know the linuxaudio-wiki has a page full of tweaks for the RPi2.

I'm afraid, but I myself didn't use a rpi, so I can't give you any hints for optimizations.

regards
hermann

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Re: Raspberry Pi 2

Postby Frank Carvalho » Mon Dec 21, 2015 4:17 pm

The command line flag is -N or --nogui


Thanks Tramp!
I later found out, but alas, the default version on the raspbian is ancient and did not have those options. Version 0.19 I think it is. I tried a very recent version on my main PC, and there I got the option to work nicely. Also installed the WebUI python scripts which all works perfectly.
I guess that if a very recent version of guitarix hits the debian armhf repositories soon, then I will rather wait it out and not attempt to recompile it myself. The list of unmet and unfulfillable dependencies was endless. So I will rather focus on the latency issue.

/Frank
Vox, Selmer, Yamaha and Leslie amplifiers. Rickenbacker, Epiphone, Ibanez, Washburn, Segovia, Yamaha and Fender guitars. Hammond, Moog, Roland, Korg, Yamaha, Crumar, Ensoniq and Mellotron keyboards. Xubuntu+KXStudio recording setup.


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