stacking shields power supply question.

Hi guys, I have a shield stacking question that boggles me, being a total noob. I’m basically trying to stack 2 shields above an UNO:

A protoshield with a micro SD mp3 player — on top of:

A megamoto plus motor shield

(driving a linear actuator that peaks at 9A, and powered separately by a 12V power supply) — on top of:

Arduino UNO

The protoshield was soldered to get power from the 5v and GND of the arduino UNO underneath it, but now that i’m sandwiching a motor shield between it, my question is: How do i power the protoshield (top shield)?

I’m fried components using the VIN previously, and a bit wary to go down that path, and I cannot stack my motor shield on top of the protoshield as the stacking pins are offset on that particular board.

Can anyone help please?

Huge thanks in advance!

That motor driver board passes 5V and GND directly through so your proto shield will have the same connection either with or without the motor shield in place.

Thanks @blh64, so this setup should be safe to test? (very scared of blowing up my motor shield again.) The protoshield will automatically get power from the motor shield / arduino?

Apologies for being such a noob, have researched forums about this but figured since I have a 12v supplied shield sandwiched it might fry the protoshield somehow.

Huge thanks!


You will want to take care of your motor shield. Some of them have a jumper installed that allows the motor voltage (12V in your case) to be connected to Vin on the Uno or not. This allows the possibility of having a higher motor voltage that the Uno can not handle on Vin (6-12V) and then the Uno needs to be powered either through the barrel connector or USB.

Thanks so much @blh64, this is precisely my issue as I fried my past motor shield doing exactly that. Powering the motor with 12v while having a wire going from the motor shield’s + power to its vin pin (which powered the arduino fine) but then once plugging a 5v through the uno’s barrel connector, boom.

Also here I would be plugging the motor shields power through the vin of a protoshield that can’t take more than 5v, I get really nervous

I think to rephrase the question I would like to have either usb or 5v power the arduino + the top proto-shield, but maintain the 12v power supply uniquely for the motorboard sandwiched in the middle :)

Thanks again!