Duet 3 and Raspberry Pi PS_ON



  • I have a Duet 3 with Raspberry Pi 3B+ running Duetpi. The Duet currently powers the RPI via the 26 pin SBC ribbon cable and the jumpers on SBC -> 5V* and 5V -> SBC. I also have a momentary button connected to a SSR to power on the board.

    Currently I have to hold the momentary button down until the RPI fully boots.

    I would like to power the RPI powered separately from the Duet 3 by it's own power supply. Last time I tried this I removed the jumper the other 2 jumpers and connected the jumper on Int 5V EN. I powered up the Raspberry Pi. When I went to power the Duet via the momentary button it seems the duet never loaded the config.

    I'm guessing that's because the SD card was still in the Raspberry Pi and there wasn't a SD card in the Duet. My question is what do I need to do to power the RPI separately and still get the momentary button to power on the Duet board ?



  • @dhusolo said in Duet 3 and Raspberry Pi PS_ON:

    I also have a momentary button connected to a SSR to power on the board.

    with the pi it'll take 10-15 seconds with recent software for the duet to load config, and take control of the duet i/o. you could move the momentary button to a gpio on the pi and issue g-code to turn on the ssr but it'll require some custom wiring and custom coding.



  • @bearer Thanks. Any advice on where to start?



  • @dhusolo Given that the Duet can still control the primary power supply through the PS-ON header, what behavior are you looking for with the momentary switch? I'm asking because I'm working on reworking my printer with a Duet3 and RPi now and had a similar setup before with my Duet2, and I'm wondering whether I want to try and replicate it, too.

    As I'm thinking about it, I'm really interested in the power supply, not the Duet board per se. At idle, the Duet is not really using that much power, and it's nice to be able to tell the Duet to turn off the main power after a print in Gcode. So I've been wondering if I might actually want to connect the momentary switch to one of the Duet's I/O headers and write a trigger to activate the SSR via the Duet.



  • @whopping-pochard This is my current wiring for my SSR and PS_ON
    SSR terminal 1: connected to switch NO and PSU neutral
    SSR terminal 2: connected to switch C and power in neutral
    SSR terminal 3+: +5V
    SSR terminal 4-: PS_ON

    With the Duet 2 I can hold the button for less than 1 second and the board will power up. With the Duet 3 I have to hold the button for 20-30 seconds. My goal is to figure out how to get the Duet 3 setup so I don't have to hold the button down for that long. The only way I figured that would work is if the raspberry pi was already powered on