Best posts made by tomasf

I just upgraded from Duet Wifi with RRF 2 to Duet 3 mini 5+ with RRF 3.2.2 and SBC. It's an awesome system, and I especially like the object model. I have a few questions about ATX power:

1. On Duet Wifi, PS_ON was off (high) by default, so the board started with power off. On the 3mini, it seems to be on by default (low)? If I put an M81 into config.g, the power is briefly on and then turns off.
   I'm using a pull-up resistor to make sure that a floating state is interpreted as off, so that shouldn't be the problem. Am I doing something wrong or is this the intended behavior?

2. The state.atxPower entry in the object model seems to always be set to false, even when power has been turned on. The web UI reflects this; if I turn on power and reload the page, the switch is shown as off again. Is this a bug or something I've misconfigured?

Thanks!

When starting a print, I have often already homed the printer (as in the printer knowing its current coordinates), but not always. If I include a G28 command in the start G-code, printing always works, but often homes when it's not strictly needed. If I omit the G28, the printer might not already be homed, and if so the print fails. What I'm looking for is a way to home the printer only if it isn't already homed. Is there a way? If not, how about a G28 parameter for this? Any other ideas?

@T3P3Tony Thank you for that info!

I tried to get good photos of the area, but the lighting isn't ideal and U9 is really tiny.

I did however spray some some canned air around the area and the main processor as well as dab some blue tack around to catch debris. I'm not yet sure if that actually helped or if it's just a temporary fluke, but the steppers now work fine, the drivers report OK with no read/write errors.

I'm now successfully printing! Let's hope it continues working. Thank you for the help!