[sdiy] MIDI VOL PEDAL with no micro??

[Ingo Debus]

Am 09.02.2014 um 11:48 schrieb rsdio at sounds.wa.com:

> I forgot to add below that, along with the 7-bit latch, you'd also need 7-bit binary compare functionality to detect changes in the Volume Pedal that require a new MIDI message. You could build this with with 7) 2-input XOR gates followed by a 7-input NOR gate (which doesn't exist, you'd need multiple OR gates, cascaded into a NOR). You could also use a logic subtractor to compare the old and new ADC values, then look for zero on the output, for which you'd need a 7-input NOR equivalent.

There are also magnitude comparator ICs, for instance the 74HC(T)688.

Roman suggested doing this on the analog side ("pot movement detection"). Maybe this is easier.

Ingo