pansapiens / hagiwo-arduino-vdco Goto Github PK

There's a bug in the Mode CV + Mode button code I need to follow up.
The Mode button on it's own works fine.

Expected behaviour:

When the button has been used to set Mode=0, sweeping Mode CV input from 0 - 5V should progressively select Mode 0, 1 or 2 (at 0v, 1.66V, 3.32V)

Observed behaviour:

The Mode CV switches modes at 2.9v and 6.9V - possible my build accidentally used an incorrect component value not matching the schematic ?

This isn't consistent with a software bug, since the switching is occurring with increasing voltage and the Arduino Nano ADCs cannot read voltages greater than 5V (they should also be clipped by the Zener overvoltage protection) - and yet we see a response at a voltage >5V.

I think this is because the GAIN socket is directly normalled to the +5V from the Arduino Nano - momentary touching of the jack before the normal is broken is causing a short.