Factory Filament Sensor, works on SD but not octoprint?


FWIW the only filament runout detects I've seen are 3 wire, 5v, Gnd, Signal.

Still very confused how runout worked for SD!

My theory is that it would have worked the same way if you connected it to OctoPrint. The LCD has its own firmware kind of thing, so it is in control of the print. When the filament runs out, the main control board doesn't know, but the screen can just send 'pause'. Things are getting more complex than the usual character LCD setup now...

Haven't tried this, how do I know what to set it to?

The filament detector does have 3x wires coming out, those 3 cables join up to a loom of cables, then this one big cable plugs into the back panel on the printer. The thing it plugs into is a small circuit board with loads of cables plugged into it, I guess to distribute everything to the right place on the main board. One of the plugs coming out of that is labelled FLD, but it only has 2x cables, not 3x. I am guessing because the small circuit board on the back of the printer uses one gnd for all the cables? Not sure.

Hi charlie,

testing with M119 shows the filament sensor as open. There is no effect whether the filament is present or not.

I have checked the pins_BTT_SKR_V1_4.h file, and I have the sensor plugged into the correct E0DET port for sure.

I have tried changing RUNOUT_STATE from LOW to HIGH, this made it read triggered at all times.

I have tried FIL_RUNOUT_PULLUP to PULLDOWN and this has no effect.

I think it must be something to do with the wiring. Can someone confirm that the red and the green cables are located on the right pins on the plug?

I have just noticed that the LED on the filament sensor is always on regardless of its position (now its plugged into the main board), does this mean it is wired incorrectly?

From your pictures, it looks like you've been plugging the 2 wire 'FLD' cable directly into the board.

Have you tried plugging the sensor in directly to the board? This would make more sense, I think. And, it's going to be difficult to verify what pins are what if there's something going on between that connector and the sensor.

No I haven't tried this but it sounds like a good idea. I have just ordered a 1m cable to try it. Thank you for the suggestion

"I have just noticed that the LED on the filament sensor is always on regardless of its position"

I can only speak for the few examples of runout detector that I've seen but in those cases the LED indicated filament runout.

Hello all!

This is my first post here and I just wanted to ask in this thread. Was this exploration given up on? It seems this was around a year ago and I just recently ran into the same thing with my new ender 3 s1 pro.-- it has a touch screen/ not rotaryknob.

Thank you all for any guidance you can give.