[sdiy] Possible MIDI interface powered by MIDI driving device...

[Dave Brown]

I did my own AVR design of a MIDI processor powered by the MIDI device.
Details, including code, are at
http://modularsynthesis.com/processor/processor.htm

I use this for a variety of reasons, but one of which is filtering out
Active Sensing and Timing Clock.  Note that power stealing isn't supported
by the MIDI standard and people on this list have criticized me for doing
so, but it works quite well on a number of different synths.  Unlike what
you posted, I went with an unregulated supply and a crystal for the AVR so
the timing would be accurate.  I found that combination worked better.  All
you have to do in the code is strip out the commands that echo the byte to
the output.  You can strip the transpose and stuff also or just hardwire the
pins.

Borrow away ...

Dave

> -----Original Message-----
> From: Synth-diy [mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of
> Jean-Pierre Desrochers
> Sent: Thursday, March 24, 2016 11:13 AM
> To: Synth-diy at dropmix.xs4all.nl
> Subject: [sdiy] Possible MIDI interface powered by MIDI driving device...
> 
> Here is a possible MIDI interface that would sink its power from a MIDI
> driving device...
> 
> http://www.arcenson.com/public/MIDI_interface_power_steeler.JPG
> 
> ---> Assuming that the driving MIDI device (keyboard, sequencer, pedal
> ---> board, etc..) is powered by internal +5VDC supply..
> The CPU would have to sink its 5vdc thru the 220 resistor of the driving
> device. Doable..
> I also think that it could work since the CPU MIDI output would be
'opticaly'
> linked with the final receiving MIDI device.
> Both driving and receiving devices would avoid ground loops while a CPU
> process is running between them..
> 
> A friend of mine asked for a simple 'MIDI active sensing code (FE)'
> hardware filter working without a DC supply..
> 
> JP
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