On Thu, Nov 27, 2008 at 02:01, Matthew Smith &lt;matt(a)smiffytech.com <mailto:matt@smiffytech.com>> wrote: Hi Folks Is anyone interested in an Open Source MIDI control surface? I'm going to be prototyping a rather basic one, to satisfy my own requirements. If anyone wants to discuss this, just let me know. (Probably best off-list as this may be Open Source, but the only connection with Linux is the fact that it is my every day operating system.) FYI, http://www.ucapps.de/

hi Matthew MIDIBox is ready to switch to AVR based cores already, i ll get within a couple of weeks the first prototype for the new ST32core (cortex), Thorsten has already ported most of functionality into the new platform. You should definitely come to the forum and the chat and let us know about the details of your project, I am sure you ll be welcome and will find all kind of nice people eager to help you out and find the best solutions. Hope to see you there! Simone aka cimo (<-- MIDIBox nick) On Thu, Nov 27, 2008 at 9:41 AM, Rui Nuno Capela &lt;rncbc(a)rncbc.org&gt; wrote: -- .wmv , .wma , .pps along with all proprietary Windows formats won t be accepted and/or viewed.... _______________________________________________ Linux-audio-user mailing list Linux-audio-user(a)lists.linuxaudio.org http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user

Quoth Ken Restivo at 2008-11-28 08:32... That could certainly be done - if you only wanted an 8-knob surface, the ADC is already on-chip. I briefly toyed with the idea of using an AT90S8535 (or the ATMEGA version), using the onboard ADC, but decided that I wanted more knobs, so went for the external ADC. But yes, for the Arduino, just add pots and MIDI interface. Not sure what the performance of a device like this would be though, when you have an extra level of language involved. Personally, I like to stick to C when dealing with microcontrollers (and for the real masochists, there's always assembly ;-)) Cheers M

hi arduino is a bit slow but if you need only a few pots to tweak parameters building up a song it may be ok. I wouldn t advise it if you need something for live acts with sensors, or you are going to multiplex the analog inputs.

For a quick, darn cheap and easy (and high resolution: 10bit) little device i ve built a couple of these: http://1010.co.uk/avrhid.html these ones send HID protocol to USB, very fast and 10bit resolution, 8 analog ins and 6 digital ins.

On Thu, 27 Nov 2008 23:35:52 +0000 simone-www.io-lab.org &lt;cimo75(a)gmail.com&gt; wrote: Although I was initially quite interested to see this, and very much liked the small size, after reading through I have severe misgivings about this project. The first issue I have is that of doing all the USB work in software rather than a dedicated chip. This takes up both processor time and memory from a little processor that doesn't have too much of either. Even with that, I notice that only USB 1.1 is implemented - and not completely. The other major problem I see, is that the author of the code first says it is GPL, then give a restriction that you must make your firmware available. The is *not* compatible with the GPL and suggests he/she doesn't have a proper understanding of it. I have no objection to people putting whatever restrictions they like on their work so long as they don't say it's something that it isn't. ttymidi is a small software module available for Linux that enables you to connect serial data (either via a D connector or via USB>serial) directly to a virtual MIDI port, and is thus ideal for any PIC or atmega microprocessor. The only quirk it has is that it expects the serial side to *always* send 3 bytes of data per command, which it will then pass on as genuine MIDI (dropping the spare bytes). This actually makes it easier to program the remote device, which I suspect is the main reason it was done. Under these circumstances the Arduino board comes out streets ahead. Not only does it have a dedicated USB/Serial chip, but it also has the full 12x digital inputs, as well as 5x10bit analoge inputs. The arduino firmware and programming software is fully GPL although the Arduino name and hardware has a commercial restriction on it (clearly stated). However the reference drawings for creating your own boards are CC licensed so again you are free to do as you like with them. Now all we need is fro someone to produce versions of ttymidi for Windows, and for the Mac :)

On Mon, Dec 1, 2008 at 4:31 AM, Tim Blechmann &lt;tim(a)klingt.org&gt; wrote: Just for my own understanding isn't MIDI fundamentally an 8-bit system? (256 max notes across a keyboard, 256 max levels, etc., ...) If so why would anything above 8-bits make any difference? Or can you specifically send controller information over multiple MIDI bytes?

Thanks, Mark _______________________________________________ Linux-audio-user mailing list Linux-audio-user(a)lists.linuxaudio.org http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user

interesting thread as i am working on a control-surface myself atm ... i would be curious, if someone has some experience with higher-precision adc? most io boards i know (arduino/makingthings) provide 10-bit adcs, while i'd be interested in getting a higher resolution ... does anyone have experience with interfacing a microcontroller (e.g. arduino) with an external high-resolution adc?

well, 10 bit is ok, but i would prefer a more accurate resolution.

does anyone have experience with interfacing a microcontroller (e.g. arduino) with an external high-resolution adc? thnx, tim

For regular 7-bit stuff, I'll be using a 16-input, 8-bit ADC. However, in order to get higher resolutions for the 2 x 7-bit messages, I am dropping analogue input in favour of rotary encoders.

Hi Tim For regular 7-bit stuff, I'll be using a 16-input, 8-bit ADC. However, in order to get higher resolutions for the 2 x 7-bit messages, I am dropping analogue input in favour of rotary encoders. The encoders that I will be using (currently on their way from China) output a 2-bit Gray code, meaning that I can read 4 of them simultaneously using a single port. (I'll actually be using 8 in a 4 x 2 matrix, scanning them just like a keypad.) $16 USD for 10 - quite a lot cheaper than pots! If your input has to be analogue, ADCs are available with many different interfaces - synchronous serial (like the TI ones I'll be using), SPI, I2C and byte-wide, which can be accessed like external memory.

I think you should read the entire post ;) btw the sofa guy is known as Seppoman, i am the lucky owner of some of his analog filter boards