Circuit - multiple piezos

[bzass]

Hi,

As I don't fully understand the circuit, I'd rather confirm - for attaching additional piezos should we use schema 1, schema 2 or something else? I assume that schema 1 but @corrados, could you confirm?

What is actually the reason we are using 3.3V pin - is it to move the point of operation? In most circuits with piezos I've seen the piezo was connected between GND and Analog IN through parallel diode / pull down resistor and another resistor in series to limit the current.

Thanks!

Schema 1

Schema 2

[corrados]

This is the correct one:

Schema 2

What is actually the reason we are using 3.3V pin - is it to move the point of operation?

Yes, exactly.

[corrados]

I'm planning to use the following setup for an initial build:

For all Dual Triggering inputs you must define two GPIO ports.

but your code uses GPIO25 for the hihat ctrl. This seems a contradiction?

No, it's no contradiction. The Hi-Hat control is no piezo but a poti sensor.

Can you I make the length of analog_pins 6 items, since I don't use the others?

Sure. I already did it for your on your prototype branch:

edrumulus/edrumulus.ino

Line 38 in 07bf51c

const int number_pads = 6;

And what about analog_pins_rimshot, how would mine look like?

See my comment above. For each Dual Trigger input you have to specify a separate GPIO port for the rim piezo. For all inputs which do not use Dual Trigger, a "-1" is inserted for analog_pins_rimshot.

And the section below // my prototype setup configuration..., how I should I configure this?

I have already pre-configured it for you on your prototype branch based in the information I had from your forums posts. As you are using unsupported pad/trigger types, we have to play a bit with the existing types to find the one which works best. In the long run, we should add support for all of your pads in Edrumulus.

[thijstriemstra]

thanks for the feedback, I've updated the table in the previous comment. And now on to some soldering..

[corrados]

I have just updated your branch with the newest specifications: d3badc8

[corrados]

BTW: I have configured your kick pad with PD-120 which will definitely not work as expected. We'll have to fine-tune some parameters to get it working correctly.

[thijstriemstra]

@corrados what email address can I contact you? I checked git log but it doesn't show a meaningful emailaddress for your commits. I'd like to send you one of my cheapo PD-5 pads (because it's christmas!) to give you something back for all your efforts so far, its been fun to work on this project. If you adjust it in git I can check it there so you don't need to paste it here). Or just check git log for my email and ping me there.

[corrados]

I have now created some KiCad files for the complete Edrumulus prototype based on ESP32.

Here are the schematics in a PDF file: edrumulus.pdf

It would be good if someone could review the schematics. I am new to KiCad and still learning...

[corrados]

There is an updated schematics in https://github.com/corrados/edrumulus/blob/main/hardware/prototype2/edrumulus.pdf