@engikeneer Thanks for everyone's help, including Idris, who responded to an Email with some great suggestions. I got the sensor working basically taking everyone's suggestions: 1/4 turn out mounting screws, faster probe speed (now 450), and lower jerk (accel @ 20). Then it was just a matter of fin-tuning the onboard potentiometer and being patient.

@engikeneer Thanks for everyone's help, including Idris, who responded to an Email with some great suggestions. I got the sensor working basically taking everyone's suggestions: 1/4 turn out mounting screws, faster probe speed (now 450), and lower jerk (accel @ 20). Then it was just a matter of fin-tuning the onboard potentiometer and being patient.

@weed2all Unfortunately, this didn't seem to work. Tried for nearly an hour to find that trigger point, but I ether just get the same (too loose to not fire upon contact) or so sensitive that any movement on z-axis would fire it prematurely. Is there a way to change the G31 behavior directly? It seems my machine has a rather abrupt direction switch at the very start of the homing, which I think if I can get rid of (or ease into better), it would allow for a more sensitive sensor.

I'm tempted to also start messing with the actual Orion mounting screws to see if I can alter the firing that way, but have gotten a few contradicting notes on that (v. snug vs. 1/4 turn loose from snug)

@weed2all Thanks for the reply. Changing the R value didn't help. Still not firing on contact and pushing hard on the nozzle for a few mm until my z-axis stalls and the belt skips.

Re: Precision Piezo z probes guide for duet users reference

I'm been having trouble tuning PPOrion on my Duet3 5+. I'm a Titan/3D3v6 hotend on a CoreXY printer and a moving Zaxis. I'd like to replace my current Z-min endstop with the ppOrion.

I'm running digital pp mode, as I can't get any analog sensor value other than '1000' in the Web Control

I installed and test fine manually: flicking the nozzle fires the LEDs as well as changes the sensor output from 0 to 1000. I can G30 to home Z when using my finger, but whenever I try for an actual bed probe, the sensor seems to fire on release/return movement and not initial contact. So when my bed hits the nozzle, the slow constant pressure doesn't set off the sensor and it results in crashing and pushing my nozzle. Changing probe speed in setup doesn't make any difference.

It seems most of the forum suggestions are for RRF2.xxx. (playing with M552 "I" commands (which is depreciated in RRF3) or reverse the sensor lead polarity (which are hardwired on the Orion). Similarly, I'm not sure if having a Duet3 I/O socket instead of a Duet2 dedicated port has any impact; I'm on I/O_1in for reference, but don't think I need any specific config setup commands for that.

my config.g lines:
; Z-Probe
M558 P8 R0.3 F250 T4200 C"!io1.in" H6; PP sensor in digital mode connected it io1.in
G31 Z0.05 ; set Z probe trigger value, offset and trigger height
M557 X20:280 Y20:280 S60 ; define mesh grid

Any help would be appreciated. Thanks

Thanks all for the assist. Just got a chance to check references, and all (unfortunately) read within spec: with a 12.14V input, I'm getting R81: 1.046V and R79: 1.04V; R80 is 10.48. Looks like I'll need a new board. At least they're back in stock...

Tried an alternate power supply (12V), and got ~20-22V on webportal Vin, so it's obviously a voltage regulation issue. Aside from the U2 3V regulator, does anyone know what could be going bad? I'm still getting solid 3.3V from U2, as well as pins 41 & 43.

After letting it sit (got busy), I tried it again this afternoon and got a solid 24V. I printed a very good calibration square without any issues. However, an hour later when uploading a model, it started reading 29-32V, occasionally dropping back to 24. Same good values at the input and on the 3V regulator

Checked the U2 regulator, and it's outputting a solid 3.28V with and without all other components plugged in. For reference, the VIn reading from the webportal is now hovering around 31V at rest, so I'm not too keen on leaving the board powered on for too long for fear of frying anything. Aside from the high readings, all other components seem to work: bed and chamber heaters, endstops (x3), wifi, and SD card.

Not from what I can tell. Nothing seems warm or looks damaged. I live in a very humid climate, but have checked all ICs and traces for corrosion or bridging from bits of debris

I've been running a Duet2 Wifi successfully for about 2 years. After not using it for about 3 weeks, I tried a simple calibration square the other day and got a 'VIn' error. At startup, it will read about 24V and slowly creep up over a few minutes to about 30V. A multimeter reading of the supply inputs to the duet is 24.9V, but the webportal reads the VIn as ~29V. All LEDs (VIn, +5, +3, wifi signal) are lit; pin 41 (ADVREF) on the expansion header is 3.28V, as is pin 43 (+3.3V). I've tried unplugging all wires but VDC, and the problem is still there. All other readings (Temps, positioning) I can get from the webportal appear fine as well.
Any suggestions would be appreciated.