PCB Design For Raspberry Pi Project

[pmi]

I have designed a “daughter board” for a Pi Zero W and I am starting to layout the PCB. I was wondering what your recommendations would be for ground, 5V and 3.3V connections. I plan to put a 40 pin header on my board and plugging in the Pi Zero.

Do you recommend connecting all the 3.3V pins on the header to the 3.3V bus, all the 5V pins to the 5V bus, and all the ground pins to ground? Or, just one of each to each power connection?

Thanks!

[paulvdh]

Just short all power pins of the same net to each other.
The reasons multiple power pins are used are for:

1. Reducing contact resistance.
2. Increaseing current handling capability.
3. Someone saw it used somewhere else and did not understand it but copied it anyway so others might thing he knows what he’s doing.
4. lowering the impedance of the power distribution (Impedance is not the same as DC resistance).

[Paulinha_B]

5. making the failure of one pin less disastreous

@paul: I like your #3 , so recognisable…
@topicstarter: are you aware that, since kicad v7, one can start projects from a template? there is at least one raspberry template available, neatly aligning the 40-pin header with the mounting holes.

Mainly: yes, as @paulvdh says, join all that you can join. If however, your particular pcb layout makes it very difficult to include one particular pin, then do not bother too much, just leave it out.

[[ a bit off-topic and a bit unfriendly, sorry I couldn’t resist ]]
@paulvdh, regarding below: this contributor’s icon comes from a famous character from Belgian comics, named “Gaston Lagaffe”. Pass “la gaffe” through a translation machine (if you need one) and much will become clear to you