[sdiy] MIDI processor - power from midi in?

[Harry Bissell Jr]

If you steal power from the MIDI signal itself, you
will lose the isolation. You could have it isolated at
the output side... and get enough power for an
occasional message.  A steady stream of messages will
take more input power than you have available.

If you are receiving multiple MIDI sources you might
combine the power, but it would be very complex, or it
would tie all the MIDI inputs together... ground loop
hell, maybe kaboom.

For very low power, yes its possible.

H^) harry

--- David Brown <davebr at earthlink.net> wrote:

> I am intrigued by the ATTINY2313 which is a 20 pin
> part which will 
> operate down to 2.7 volts.  Since it is compatible
> with all of the 
> AVR parts, I was able to port my code from my
> keyboard 
> microcontroller
> http://modularsynthesis.com/kurzweil/kurzweil.htm
> 
> I now have a full midi-in to midi-out command parser
> running and a 8 
> bit data pins available.  So far I am just doing
> simple midi 
> transformations such as note transpose, note invert,
> and channel 
> transpose.  I'd like to power this off the midi in
> connector and 
> think it will be pretty simple to do.  Anyone done
> this?
> 
> I'm thinking of using the bits for command selects
> and using this 
> processor to split keyboards, add additional midi
> notes on separate 
> channels, etc.
> 
> Dave 
> 
>