I'm sure this is answered elsewhere but the only (unanswered) question I found was on Amazon.
I've recently swapped out my RAMPS 1.4 board for a RAMPS 1.6 and noticed that between RAMPS 1.4 and RAMPS 1.5 the PS-ON pin, which would be tied to the PS_ON input on an ATX power supply (enable PSU by pulling low) is no longer present (it used to be next to the reset button).
The obvious alternative is to connect this directly to one of the many available GPIO pins on the Raspberry Pi I have running Octoprint, and intercept the M81 / M80 gcode commands via the available plugin.
I'm reading the schematics here: [
github.com]
Ha ha! Not really a schematic for anything but external connectors.
It looks like there is now PSON at J5 near the E0 stepper driver socket. I am probably the first person who was too dense to notice this right away!
So I think I've answered my own question.
