cv to midi??? (fwd)

Mikko Helin helin at
Tue Nov 9 17:32:30 CET 1999

The idea is the same as on page

where the pot is read by calculating the time it takes either to charge or
discharge the cap. With this circuit no separate AD converter is needed.

OT: This method can also be used to sense the drum trigger velocity for
MIDI drum brains. Drawback is the inbuilt slowness, as it takes some time
to charge the cap. For reading pots it's propably OK, but for triggering
MIDI notes for percussion it may be too slow, I don't know, maybe not.
With piezos two input ports per trigger are needed, one to sense the
"start" of drum hit and the other to measure the time to charge the cap
through a resistor. The harder the drum is hit the faster the cap charges.

PIC16F84 has 8 pin PORTB and 5 pin PORTA and one pin is needed for MIDI
out, so that makes for 6 trigger inputs with velocity sensitivity, not
bad. With force sensing resistors only one input / trigger is needed.


----------  message ----------
Date: Fri, 05 Nov 1999 07:15:23 +0000
From: John E Blacet <blacet at>
To: "..," <poker3 at>
Cc: synth-diy at
Subject: Re: cv to midi???

You might be able to use this....

John Blacet
Blacet Research Music Electronics
blacet at

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