Piezo trigger question?

#1

my piezo and push sensor experiment feels very good ...
Now my 2 piezo disk are connected /audio in
with the patch i founded in the libary
very musical when connected pitch with expression pedal
my question can i connect more piezo disc with axoloti ?
schmitt trigger ? i am confused ...
i am afraid of the spikes piezo's
can produce .

The piezo disk feels good and gives it rhythm
it's amazing when connected with sample/hold
got a strange squeezing effect when pressed more like a teddy bear ...
any ideas ?

#2

I played around with getting piezo inputs to to work with my e-drum kit (and ended up going with an arduino instead). If you want to use the regular analog in pins, you'll probably want a simple input filter circuit using an op-amp to preamp and limit the peaks of the signal. @timvets mentioned he'd used some piezo disks via the regular analog pins in this thread: https://sebiik.github.io/community.axoloti.com.backup/t/analog-inputs-for-trigger-to-midi-capability/604

#3

Hi reinhard,

You're in right with your fear about spikes: I had the same problem with the GPIO of an MCU, and
I resolved it with a simple add-on.
I think that this circuit with a 3.3V zener diode could be useful.
Best regards