Adafruit DC Motor Bonnet - Header for Stacking


Quick question about the Adafruit DC Motor bonnet

I’m looking to use this with a Pi Zero. I see that it has a female header to connect to the Pi Zero, I would like to add a header on the top to access additional pins for sensors etc. The description says this is possible.

Can I use the GPIO Hammer Header (Solderless) for this purpose?

Thanks for any help.


That’s not going to work. The Hammer Header is a dual row header. The Motor Bonnet extra header is a single row header. This should work, you’ll have to solder it though.
Break Away Headers - Pimoroni

Thank for getting back.

The picture of the bonnet appears to show a dual row header (2x20)

and the description of the product states
“In fact, you can even stack multiple Motor Bonnets , up to 32 of them, for controlling up to 64 stepper motors or 128 DC motors (or a mix of the two) - just remember to purchase 2x20 stacking headers.”

I may not have been clear that I was not referring to the single row (1x25) but the dual row 2x20.

  1. Can a GPIO Hammer Header be used as a stacking header?

  2. Can all pins be access from the stacking header or must they access from the single row (1x25)?

Hope that make my question clearer.


Ok, thanks for the extra info. There is a female 20x2 header on the back side that lines up with those double row of holes. When you plug the bonnet onto the Pi, do the Pi’s Male pins go through / fill those holes?

One way to do it is with a Phat Stack.
pHAT Stack - Pimoroni
HAT Hacker HAT - Pimoroni

EDIT: I guess that’s two ways. ;)

Keep away from hammer headers. They are not meant for stacking. Even if you don’t want to stack, don’t use them.

Explicit stacking hackers are what you need for your use-case. On the bottom side female, on the top side male. So you plug the stacking header to the Pi and then the bonnet to the header.

The wrinkle here is that there is already a header soldered too the bonnet. That complicates things.

The only solution I can think of here, though it may be too late now (if the Pi-Zero already has a header fitted), would have been to put extra tall header pins on the Pi-Zero such that when the bonnet is pushed onto them there’s enough remaining header pin to poke through the holes in the bonnet’s top surface to plug a stacking header onto.

You do need up to 10mm of header pin to reliably reach the contacts inside a stacking header’s female end.

As suggested, a pHAT stack may be the better way to go.