AW: [sdiy] 3.3V and MIDI

[Neil Johnson]

> As the MIDI interface is a current interface (nominal 5mA) it should be
> no problem as long as the current can be sinked on the MIDI outport. But
> you will have to adjust the resistor (normally 220 ohms) values so that the
> current of 5mA can flow.

Handwaving solution, for 3v3 wee need 320 ohms in circuit for 5mA (allow
1v7 for photodiode)

> Remember that the receiver also has a 220 ohm resistor on teh input.

So need 100 ohms in the sender.  Should be ok.

Cheers,
Neil

--
Neil Johnson :: Computer Laboratory :: University of Cambridge ::
http://www.njohnson.co.uk          http://www.cl.cam.ac.uk/~nej22
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