i’am using modulars since about 4 years now and from time to time i try to build some modules by myself, mostly replicas of already existing schematics.
i also own a few mutable modules and i like the fact that all schematics/codes are available and i think that mutable instruments is the most innovative module maker out there by the way
lately i felt the need for a cv’able peaks module and i tried to modify my peaks to get this missing part added.
I divided the middle pin of the pot (0-3.3v) and used a basic cv mixer (tl072 as 2 stage inverting mixer) to mix the 0-3.3v and the incoming cv and connected the output back to the pcb where the middle pin of the pot was connected.
it works pretty well so far on my bench but i have a question because i don’t want to destroy the smt32 chip…:
what is the max +/- voltage the stm32 is able to handle on the pot_1 - 4 pins?
i know, peaks is 0 -> 3.3v and minus won’t do anything but i just don’t know if i have to protect the stm32 from minus voltage.
also the max plus voltage is not clear to me.
it’s 3.6v or 5v according to the datasheet, was not able to find the correct max value for pin 10-13…
I used a zener diode after the mixer to limit the voltage and a standard diode to prevent minus voltage till now but maybe it’s not needed if the voltage limit is higher than 3.3v and minus voltage is not a problem for the smt32…it means i can save a view parts for the final build.
would be cool if someone could help me with this.