midi controller


13 posts
by urbanspaceman » Sun Dec 04, 2011 7:32 pm
hi, i think a sort of midi controller / instrument with a linux distribution + pure data inside. PureData should start automatically on boot and load a patch.
The problem is how to interface with buttons and knobs?

perhaps with an Arduino ... or the GPIO?
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by Montekuri » Sun Dec 04, 2011 7:36 pm
Maybe these topics can be of some help:
- Portable lab for musicians
- Teaching & Learning Music Notation

And this page that I found using google: Getting Started with MIDI on Linux
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by urbanspaceman » Sun Dec 04, 2011 7:46 pm
I'm going to read through. tnx
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by urbanspaceman » Sun Dec 04, 2011 7:48 pm
ok i have already read this topics.. but my question is different, is a hardware question. (sorry for my english)
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by Montekuri » Sun Dec 04, 2011 7:54 pm
I think you must use a usb music keyboard.
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by kelytha » Sun Dec 04, 2011 8:09 pm
Or just a USB - MIDI Interface. It is a cheap option also if you already have your MIDI devices. I do that already here, playing music on my desktop PC that runs Arch Linux.
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by urbanspaceman » Mon Dec 05, 2011 10:05 am
ok but my idea is to make a stand alone box with Rasp+knobs, i'm in the computer music from 1999
and already have a lot of instruments and midi interface. I have already built electronics for music and will want to experiment with something new.
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by ProDigit » Mon Dec 05, 2011 7:52 pm
First thing, this Linux will probably not have an ASIO driver yet (or something similar).
If it does, the latency of this device will be significantly higher than from a PC, why?, because the CPU has very little, to no L-cache! Also the cpu is pretty slow.
Good enough to run a single instrument through, but once you start to have polyphonic, multi layer instruments, that have a variety of analog control settings; like attack and sustain variables depending on how hard you hit a key and keep it pressed in, this CPU might not handle the stress.

Even then it would be advisable, to find a flash drive (non SD) that has high iops, and connect it via a bus other than USB. USB will increase latency considerably too!

But it is possible. If you want best results, you'd probably have to plug in a fast USB stick into the USB port, without HUB, as sample drive, and connect your USB midi device to the other port (or connect a HUB inbetween so you can add a mouse and keyboard, and other low bandwidth devices).

I think the biggest issue is finding software that will run on the raspberry's os, and preferably software that is optimized for the pi. Also software that has a 'learn' mode for midi knobs, and a midi controller that will be recognized out of the box!
Some of the more advanced midi tools over USB need drivers. You don't want to run wine on the raspberry (doesn't work I heard, and even if it does, would be too slow).
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by kkolev » Mon Dec 05, 2011 9:41 pm
Just to butt in the thread - if you're looking for a cheap control surface, the nanoKontrol ain't too shabby. Example link (I have two of the ones in the picture due to a delivery snafu): http://www.amazon.com/Korg-nan.....B001J8LJWK

9 sets of: fader, knob, 2 buttons.
Transport controls.
4 'scenes', i.e. presets uploaded via the Korg whatever-it-is program that can interface with the thing.

Overall quite useful to control me some RGB LEDs with an Arduino. But now I have to wait for the raspi for something silent to serve as a bridge between the control surface and the bit-jiggler, cause I'm too lazy to fiddle with midibox os on the lpcexpresso...
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by urbanspaceman » Tue Dec 06, 2011 1:09 pm
see this instruments http://www.teenageengineering......ifications
raspberry might be a good platform to develop tools like this.

CPU
400 MHz Processor Core
(800 MMACSS performance)
64 MB Low-Power SDRAM (12ns)
512 MB Nand Flash storage
24-bit 96kHz ADC/DAC
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by harmono » Wed May 30, 2012 12:20 am
There is an interesting kickstarter project called Makey Makey that enables you to create a computer keyboard out of anything that conducts electricity (I think), for example, you want to make a keyboard out of bananas, you hook the banana up with a clip to this board, and there you go. So theoretically if you wanted to send basic midi notes you could send it through the keyboard (need a special app that takes keyboard input and routs to MIDI though). I'm trying to make a keytar so I was looking into solutions. I would like to have touch sensitivity though.
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by TonyD » Wed May 30, 2012 12:31 pm
urbanspaceman wrote:..
The problem is how to interface with buttons and knobs?
perhaps with an Arduino ... or the GPIO?


Personally I like the idea of using the GPIO to keep the USB ports free, so I'd designed a small MIDI In/Out board for the RPi using the GPIO Expansion header, checkout the entry for "RPi MIDI Breakout Board" on the RPi wiki http://elinux.org/RPi_Expansion_Boards
Tony
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by CZUKONE » Tue Jun 05, 2012 10:11 pm
I like the sound and look of your MIDI board and I'm interested in trying to put one together.

Any idea of how much the parts would cost and where to get them in the UK?

Cheers.
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