Beginners • Re: RPI for ATX PSU power status sense wiring question

If all you need to do is sense whether the ATX PSU is on you need to connect two wires:

1. The PSU's output ground to one of the Pi's ground pins.
2. The PSU's 3.3v line to a GPIO input pin.

You'd then either enabled the interal pull down on your chosen GPIO or, as shown in the diagram use an external 10K pulldown resistor on the same GPIO. A pull down is required to avoid the input floating (and therefore giving inaccurate results) when the ATX PSU is off.

Statistics: Posted by sotirone — Sat May 11, 2024 10:52 am