1.75mm Inline Filament Roller IR Sensor Version 3

A Kickstarter campaign for this product is live:
https://www.kickstarter.com/projects/522476987/filament-roller
Make a donation and receive a finished Filament Roller. Thanks for your support~

This is a prototype IR sensor and alarm which detects the direction and speed of your 1.75mm filament spool. This sensor will sound an alarm when your spool stops due to:
- filament-jamming,
- nozzle-clogging,
- extruder-grinding,
- motor-stalling,
- out-of-filament,
- or