Identifying Grounds

Any pointers? I can identify grounds when the trace connects multiple buttons but on the logitech wireless pcb start and select’s ground and signal are single traces and don’t meat up until the “brain”.

Also, what is the difference between a pcb with a common ground or not, as in, how do you know when you can get away with daisy chaining.

Thank you.

picking out grounds is usually easy, since they don’t have any chips at all attached to them.

typically… they’re the big thing…

see the cross between the buttons here? notice how there’s metal there, but there’s no chip, yet all four pieces are connected with that big cross? that’s the ground.

Understood, but as I said it is an area of the PCB that is not easy to identify. The ground does not meet up with any adjacent buttons before going to the chip so just like the signal it is a solo trace. I may have to bust out a multi meter, but before I make that investment I’d hoped to find an easier, visual solution. TY

Haven’t we gone over this before?

Then it doesn’t use a common ground. Wire two wires to each button/direction.

If in doubt and you don’t want to buy a multimeter, just wire it up with a ground for every button. Daisy-chaining is the shortcut, but you can always take the longcut no matter what kinda PCB you’re working with. Daisy-chaining doesn’t save THAT much time anyway, unless you’re terrible at soldering. It does save space though.