DUET with Xbox PSU

Hi all, I have a mini kossel but asking here as its the home of the DUET.....

I'm aware the DUET and DC42s firmware can now control and ATX power supply using M80/M81. An ATX needs PON to be low (0V) to turn the supply ON. GREAT.

BUT, an Xbox power supply (as i have laying around unused) needs to be pulled high (3-5V) to turn the supply ON. It still has a 5V standby like an ATX.

Is this something that can be done in the firmware?

Its not just because i'm cheap and have one already but the power 'brick' is a neater solution than a bare ATX on my desk.

Thanks in advance.

I can think of 2 possible approaches:

1. Feed the 5VSB power into the ATX5V input so that the microcontroller is powered permanently. Add a pullup resistor between the PS ON output and 5VSB. Then use M80 and M81 in reverse, or reverse them in the firmware. This doesn't save much power though compared to just turning the motors off.

2. Use an NPN transistor or small N channel mosfet, and a couple of resistors to 5VSB, to invert the PS ON signal. That way, you can power down the microcontroller etc. as well. That would be the better solution. You will also need to add a pulldown resistor on the Duet to fix a known issue in the PS ON circuit.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Having the printer on 'stand by' by having the 5V always on but with everything 12V powered down is what i'm after. The Mrs worries that I'll burn down the house in the night. Just the fact that the fans and 12V light are still on in the morning makes her worry.

I wasn't sure if just running the commands in reverse would work and pull up to 3-5V, sometimes these sort of 'switches' are just left open when not pulled down, good to see that is not the case here.

You mention they could be reversed in the firmware, this would make sense in this case so when using the web app, ATX ON means what it says and is not reversed. How would i go about doing that?


It may be related but i'm finding the SD card is becoming corrupted causing the web app not to connect. Sometimes when putting the card into a PC it will pick it up and offers to 'fix' the SD card, after doing this I can connect again. Could this be caused by 'hard' shutdowns? I know on the R Pi if you don't shutdown correctly it can corrupt the SD, i wondered if that is happening here? I don't know nearly enough about the firmware and this is just speculation of course.

Thanks again.

I always shut down my printer via a hardware switch and that does not effect the card - the new one. I had trouble with the boxed Kingston class 4 card so I replaced this card with a Transcend 16GB class 10 and that works without any problems. A minimum of class 6 is recommended for using with the Duet. It seems that the Kingston card nearly reaches class 6 otherwise it would not work.
However I am not the only person here that recommends exchanging the shipped card with a class 10 card.

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Slicer: Simplify3D 4.0; sometimes CraftWare 1.14 or Cura 2.7
Delta with Duet-WiFi, FW: 1.20.1RC2; mini-sensor board by dc42 for auto-leveling
Ormerod common modifications: Mini-sensor board by dc42, aluminum X-arm, 0.4 mm nozzle E3D like, 2nd fan, Z stepper nut M5 x 15, Herringbone gears, Z-axis bearing at top, spring loaded extruder with pneumatic fitting, Y belt axis tensioner
Ormerod 2: FW: 1.19-dc42 on Duet-WiFi. own build, modifications: GT2-belts, silicone heat-bed, different motors and so on. Printed parts: bed support, (PSU holder) and Y-feet.
Ormerod 1: FW: 1.15c-dc42 on 1k Duet-Board. Modifications: Aluminium bed-support, (nearly) all parts reprinted in PLA/ ABS, and so on.

I'm using a Skandisk 16gb class 10, although i'm not sure its genuine. May try another.