Feed sensor

Back bearing that rides agains the filament is constantly rotating when filament is fed.
I understand that there are retractions that take place that could complicate the idea of the design but not the device.
I remember old track players had analog dial that would roll as tape plays. Some fancy once would have photo diode sitting at both sides of the rolling disk with holes. As it rotates, hole would roll on and open up the view for the photo diode.


The same principal can be applied to get filament feeding check. If diode is visible or invisible for more then (depending on the feed rate) then pause printing.

I dont have any hardware program knowledge but i do program small apps for windows so my look on that would be as simple as:

Code:

$FeedRate = "X" ;Print area per second formula required
$BearingMotion = "GetBearingMotion"
$Opening_Closing_Time = "0"
While 1 ;Loop starts
    If $BearingMotion = "Moving" Then
        If $Opening_Closing_Time < 1 Then ContinueLoop ;Continue loop.
        ;because opening and closing is less then 1 second indicating its motion.
    EndIf
    If $Opening_Closing_Time > 1 Then ;If opening or closing takes more then 1 second
        PausePrint
        Alarm
        Wait for user to resume
    EndIf
WEnd ;Loop ends