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DIY Stompboxes => Digital & DSP => Topic started by: Taylor on July 03, 2010, 10:15:26 PM

Title: Sending a single MIDI sysex with a microcontroller
Post by: Taylor on July 03, 2010, 10:15:26 PM
I have just built a polyphonic MIDI synth using a computer soundcard as the brain (more info on that project later, it's really fun).

In order to access most of the sounds in this thing, I need to send a sysex message. But the whole reason I built this unit was to have a physical keyboard that's not part of my computer, so I need a hardware box that can send this one measly sysex message when I hit a button.

I happen to have a bunch of PIC 16f684s laying around, so if it would be possible to use that chip, that would be great.

What would I need to do to write a program that just sends this one message? Are there any code examples similar to this that I could dig through and adapt?
Title: Re: Sending a single MIDI sysex with a microcontroller
Post by: David on July 04, 2010, 10:32:51 AM
There are reams and reams of stuff.  Thorsten Klose's "Floorboard" (although that was written for a 16f874) comes to mind.
Another example is an adaptation that Josh Harle made to bit-bang serial output of a MIDI note number at 4MHZ so he wouldn't have to use an external clock.  I think that used a 16F684.  The point of that is that it's a very short leap to formatting and sending SYSEX messages.
Title: Re: Sending a single MIDI sysex with a microcontroller
Post by: G. Hoffman on July 05, 2010, 03:59:18 AM
THIS SITE[\url] has a couple of assembly transmitters for 16F84s.  I'm sure you could easily modify them for a 684.


Gabriel (http://www.audiomulch.com/midipic/)
Title: Re: Sending a single MIDI sysex with a microcontroller
Post by: potul on July 05, 2010, 05:24:36 AM
hi

Once you've tried a PIC with an integrated UART, it's a pain to go back to software UARTs...  I would recommend to use something like a 16f88 or a 16f628. I've recently programmed a MIDI controller that uses sysex to communicate with a PC, so I could help if needed.
But when stepping into programming the serial interface and consider all timing issues associated to it, I'm a noob...

Regards,

Potul
Title: Re: Sending a single MIDI sysex with a microcontroller
Post by: deadastronaut on July 05, 2010, 09:19:48 AM
dont know if this helps...been looking at building midi drum kit with transducers...

rob.

http://highlyliquid.com/midi-controllers/ (http://highlyliquid.com/midi-controllers/)