ATX to GPIO: 3V3 or 5VSB or PS_ON? (PSUControl)


I feel absolutely dumb or maybe I'm under a huge misapprehension. Or maybe both. So PSUControl is for controlling an ATX PSU that is commonly used in a PC, right? Or is this plugin only for these relay boards I see whenever I try to google my "problem"?

If it is not only for those relays, how do I connect my ATX PSU with my RPi? My RPi is powered by the ATX's 5VSB just fine. But how do I proceed so that my RPi can switch the ATX on and off? I assumed that I would have to connect the PS_ON pin to one of the the RPi's GPIO pins. I also read in the open issues for PSUControl about the 3V3 and PW_OK pins. Do I have to use those?

I feel so stupid as I'm searching and researching for days but I simply cannot find resources about that topic. All I see is people using the relays or connecting PS_ON to GND.

I really hope that you can help me. Thank you so much!

Edit: I got it working with the ATX's PS_ON pin on one GPIO and a 3V3 pin on another GPIO. However, I wonder if i need some kind of resistor/diode/voltage devider so that I don't fry my Pi. Can somebody elaborate please? Thank you!

Can you explain how you got it to turn on? Just connect the PSU_ON to the GPIO pins?

As I mentioned in my edit of my initial post:

  • PS_ON from ATX to one RPi GPIO (switching)
  • 3V3 from ATX to another RPi GPIO (sensing)

In PSUControl, I also checked the "Invert" for the switching pin. Keep in mind to use the BCM layout numbering of your RPi's GPIO pins.

i'm still not sure if i'm going to fry my pi with this setup. can anybody help please?

PS_ON is active LOW so use a simple NPN transistor to short PS_ON to a ground on the ATX. Put a 1-10k resistor on the base pin. Hacked this diagram up.

For sensing you can use the 3.3V rail or 12V with a voltage divider. With either be sure to put a 1-10k resistor on the GPIO side.

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thank you for your reply! so in essence, you recommend the following wiring, right?

source: Using the Raspberry Pi to Control an ATX Power Supply : 3 Steps - Instructables

Seems alright though I personally used to wire 5VSB to the Pi header and not the USB.

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in your comment Needs a wiring diagram Β· Issue #81 Β· kantlivelong/OctoPrint-PSUControl Β· GitHub you mention the pw_ok pin and the 3v3 pin: could you elaborate on this wiring? would the pw_ok and 3v3 pins be used in conjunction with the ps_on pin? would the transistors and resistors be necessary?