Setting up PWM / Servo Bonnet for solenoids

adafruit.io wippersnapper BETA support, discussions, and more!

Moderators: adafruit_support_bill, adafruit

Forum rules
If you're posting code, please make sure your code does not include your Adafruit IO Active Key or WiFi network credentials.
Locked
User avatar
kashik
 
Posts: 3
Joined: Fri Jul 22, 2022 12:23 pm

Setting up PWM / Servo Bonnet for solenoids

Post by kashik »

Hello all!

I am trying to make a complex object and I need to control multiple solenoids (at least 32) using Raspberry Pi and custom python code. I am designing now the hardware connections and I think two of the Adafruit 16-Channel PWM / Servo Bonnet for Raspberry Pi (https://www.adafruit.com/product/3416) is what I am looking for? Somehow I can access read and write in in the Raspberyr Pi for this module and then I have 32 channels that I can arbitrarily control. I would like to ask if this is the right path, and if so, what Solenoids do you recommend for this board? I want to be able to push the equivalent to finger press on old keyboards. I'm not sure if I need anything else?

Raspbery Pi 4 model B -> 2 Adafruit 16-Channel PWM / Servo Bonnet and 32 x solenoids.

Thanks in advance.

User avatar
adafruit_support_carter
 
Posts: 29168
Joined: Tue Nov 29, 2016 2:45 pm

Re: Setting up PWM / Servo Bonnet for solenoids

Post by adafruit_support_carter »

You'll want something else for driving solenoids.

Checkout these projects:
https://learn.adafruit.com/robotic-xylo ... uit-python
https://learn.adafruit.com/wireless-ble ... e/overview
for some examples.

User avatar
kashik
 
Posts: 3
Joined: Fri Jul 22, 2022 12:23 pm

Re: Setting up PWM / Servo Bonnet for solenoids

Post by kashik »

Ok so, let's focus a bit on that answer.

Using the Arduino example. Doing this (https://learn.adafruit.com/robotic-xylo ... id-circuit) four times is a good option? I may need to connect all of the arduinos together in the single codebase, that doesn't seem a great option but want to hear what do you think?

Regarding the wireless example, (also I don't really need that bluetooth) it seems a fairly elegant implementation. I'm ok with MIDI, just need a replacement for the bluetooth, and would pretty much like to get this in normal python.

What do you recommend?

User avatar
adafruit_support_bill
 
Posts: 88093
Joined: Sat Feb 07, 2009 10:11 am

Re: Setting up PWM / Servo Bonnet for solenoids

Post by adafruit_support_bill »

You could use the PWM/Servo board - or one of our GPIO expander boards to get enough channels. But you would still need a MOSFET and diode on each output pin in order to drive the solenoids.

A Grand Central board would also give you enough pins. But you still would need the MOSFET/diode driver, since a GPIO pin will not drive a solenoid.
https://www.adafruit.com/product/4064

User avatar
kashik
 
Posts: 3
Joined: Fri Jul 22, 2022 12:23 pm

Re: Setting up PWM / Servo Bonnet for solenoids

Post by kashik »

Ok so that is great.

I think I got my system here without bluetooth keeping the same materials as in https://learn.adafruit.com/wireless-ble ... e/overview.

Now the MOSFET and diode driver can I buy from this store too? Kind of trying to make a basket that matches

User avatar
adafruit_support_bill
 
Posts: 88093
Joined: Sat Feb 07, 2009 10:11 am

Re: Setting up PWM / Servo Bonnet for solenoids

Post by adafruit_support_bill »

MOSFETs here: https://www.adafruit.com/product/355
Your diodes should be rated for at least as much current as your Solenoids will draw.
We have diodes here rated for up to 1A : https://www.adafruit.com/product/755

Locked
Forum rules
If you're posting code, please make sure your code does not include your Adafruit IO Active Key or WiFi network credentials.

Return to “Adafruit IO Wippersnapper Beta”