If the probe reading only drops to 600 when the sensor is activated, then it sounds to me that it isn't compatible with a 3.3V supply. One possibility is to run it from 5V and feed the output through a couple of resistors to an NPN transistor which drives the E0 endstop input.
I'll probably add a firmware option to invert the Z probe polarity for type 1, 2 and 5 Z probes at some point, then you will be able to connect it directly.
Added mine to Thingiverse as well http://www.thingiverse.com/thing:1830918. It has an enclosed 80mm fan to blow on the underside of the board, exhausting through slots top and bottom. Cable entry is left side but I've included the open scad file so it'd be easy enough to change.
Several metres is no problem, but I recommend that you limit the resistance per conductor to 0.1 ohms. For really long cable lengths you can reduce the baud rate. However, if you are using the ribbon cable to connect the SD card socket on the version 2 PanelDue then the maximum recommended ribbon cable length is 0.5m and I have only tested up to 0.8m.
Since it is an employment requirement, breaking the policy would likely result in job action so that is why I do not consider a non-public SSID an option. I will probably just operate via USB until I move off campus (last year at this job). Thank you for the help, I missed the documentation on USB control.
Please measure 3.3V and ground on the sensor itself, between the top end of the inductor labelled L1 and the ground test point between D2 and R3. If you are getting 3.3V between those but the LED doesn't flash about 5 seconds after power up, then your sensor needs to be replaced.
That would be also my expectation.
The moving wires are the heatbed, but this runs over a SSR and I do not think a short circuit would cause this behaviour over the SSR.
I removed also the bed Thermistor (but did not heat then the bed) and still the issue.
So could be the wires running from top to the printhead carrier. I renewed already the connector to the IR probe, as this looked a bit suspicious.
As it looks as I'm the only one having this issue, it mustbe something with my build ?.
I will be next week on vacation and afterwards I replace the Duet 0.8.5 by the Duet Wifi. Lets see if this changes anything in this behaviour.
It is a pitty that the error occours only from time to time, making trouble shooting much harder.
I gave up on the Tunell monitor as I didn't want to risk the electronics on my Duet.
I designed a simpler filament monitor using an optical sensor and a housing to hold the filament in the path of the sensor. You could do the same thing with optical or mechanical endstops. It will get you the filament out detection but not the tangled filament or clogged nozzle detection.
The only acrylic I have to test the IR sensor against is black acrylic, and the sensor works well with that. The usual issue for the IR sensor with transparent bed surfaces is that the reflection from the back surface interferes with the reflection from the top surface, and this causes the trigger height to depend on the relative strengths of the two reflections. Your acrylic may be opaque enough to avoid that.
I agree on this one, I just did not want to bring it up. If the standard blower was used, it is unlikely that it can cause a drop of 10C. My guess is that either PID settings are wrong for some reason, or, most probably, the Rostock hot end has developed issues. So, going to a more standard hot end such as E3D would solve the problem.
I have seen other complaints about the 10C excursion limit, so perhaps an ability to temporarily override it could be useful, but I agree that fixing problems makes more sense.
Personally I'm a bit puzzled by all of this. I don't want to upset anyone here but aren't we asking for the firmware to be modified to compensate for some defect in the printer design, when in fact we should be looking to rectify the root cause of the problem?
I tried to reflash the firmware but the board is not even detected by the software. Tried from another computer on both Windows and Linux, still no sign of life.
EDIT : nevermind, I actually managed to reflash the DuetWifi firmware, also I reflashed the PanelDue's itself with its own firmware via bossac utility.
Everything seems to be functional, will test tomorrow with stepper and heatbed wired.
EDIT 2 : Everything is working as expected. My metamorph 3D printer project can now continue 🙂