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Connecting shoulder buttons to ground - where? [SOLVED]
Posted: Thu May 23, 2019 12:41 am
by mrsippy
Hey all,
I have this button PCB:
...and have a question re connecting shoulder buttons.
I know that I need to connect one pin from the left button to "L" on the PCB, and one pin from the right button to "R" on the PCB, and, on each button, I need to ground the other pin, but where do I ground them? Do I solder them both to "GND" on the PCB? Do I then also solder a wire from "GND" on the PCB to a ground on the Pi? Or do I connect the remaining pin on each of the buttons to a spare ground on the Pi? If yes, what do I do with "GND" on the PCB?
Many thanks in anticipation.
Re: Connecting shoulder buttons to ground - where?
Posted: Thu May 23, 2019 5:23 am
by floppes
Generally speaking, you should have all GNDs connected. The GND of the Raspberry Pi should be connected with the GND of your PCB and the GNDs of your shoulder buttons. That's called a "common ground". How you do this is up to you.
Re: Connecting shoulder buttons to ground - where?
Posted: Thu May 23, 2019 5:58 am
by mrsippy
Thanks floppes!
I have my display grounded next to the TV pin (I'm using a composite cable), it would be difficult to connect anything else there, I take it it would be ok to use a different ground pin on the Pi for the other things that need to be grounded?
Re: Connecting shoulder buttons to ground - where?
Posted: Thu May 23, 2019 6:26 am
by floppes
Yes, the Pi has several GND pins. They are all connected internally. You can use any of them.
Just make sure your solder connection is good and the wire is thick enough for the current it has to conduct.
Re: Connecting shoulder buttons to ground - where? [SOLVED]
Posted: Thu May 23, 2019 7:03 am
by infinitLoop
be aware - the L and R on that board are for the buttons on that pad - they are for a six button layout on the front.
if you are actually doing "shoulder" buttons, in the rear, then you would leave those unconnected on that board and wire the buttons (or a board if you get one) in the back directly to the pi. you would also ground both of those to something on the pi.
Re: Connecting shoulder buttons to ground - where? [SOLVED]
Posted: Thu May 23, 2019 7:35 am
by mrsippy
infinitLoop wrote: ↑Thu May 23, 2019 7:03 am
be aware - the L and R on that board are for the buttons on that pad - they are for a six button layout on the front.
if you are actually doing "shoulder" buttons, in the rear, then you would leave those unconnected on that board and wire the buttons (or a board if you get one) in the back directly to the pi. you would also ground both of those to something on the pi.
Thank you so much infinitLoop, I was about to solder them on! So glad you pointed this out.