@dc42 it was a while since I posted. After I read thread you mentioned I mounted sensor as close as possible to extruder and since then I did not receive any failure or false alarm (printed couple spooles).
@alankilian I have it right before the extruder, I am trying to avoid placing it in line between the Hotend and Extruder as I have had issues with that with the BTT smart F sensor on my other machines. Changing the sensitivity seemed to do it. I was able to print with it. Sensitivity can be adjusted later should it be too weak. My esteps look good so I have my doubts about that being a root cause. I am happy with the progress made on this now. Took me a year to figure out what we did in these few days. Ill play with the settings but the root issue has been solved.
Would be great to have diameter sensing, filament-runout sensor & jam detector in one housing. Maybe they can read the vibration caused by the scratching needle on the moving filament? Piezo-disk as vibration detection perhaps? Or the classic encoder.
@JohnOCFII that is nice, obviously the encoder input is not having Schmitt trigger input so simple analog devices will not work. Not sure why 'cause if I remember correctly these inputs can have ST input turned on in port configuration. One hint - what logic analyzer sees and what duet sees are not identical!!! It is similar as you have a similar input port on the CY in the logic analyzer as is on the SAM in duet but they are not the same.
@alankilian i do it like that to. but i thought this would be a more precise tool to use. It says "measured sensitivity 25.43mm/rev, min 97% max 103% over 410.6mm" i assume that means over 410.6mm of filament.