> Such a software would have to vary according to the keyboard model, the > available GPIO ports and the extra electronic components used (e.g. > shift registers or de-multiplexers). Most keyboards are arranged in a matrix fashion so they have about 16 wires for a 64 notes keyboard. this may already bee too much for a raspberry, so using a multiplexer is probably mandatory. > A general purpose operating system like Linux is not best suited for > such an application, since the scanning rate should be in the > sub-millisecond range to get a good velocity resolution (assuming you > have a keyboard with two contacts per key). > > A project that generally does what you want is midibox. Yes, i have built several midiboxes and also arduino alikes, so very familiar with this easy and efficient way to do midi thing. I mentioned I would like to avoid extra boards and use ressources existing on the cpu board. A few multiplexer chips are still easier/cheaper than any midiboard. As you say, the sub-millisecond timing for the keyboard scanning is important, so if it is not doable in-the-box, even with some real-time kernel and associated module, i would certainly go with those solutions. Raphaël _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
