Filament Width Sensor with Arduino Pro Micro and TSL1401CL

WARNING: THIS THING IS OUTDATED.
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Please visit http://www.thingiverse.com/thing:704897 for updated version.
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I've modified *flipper*'s great filament width sensor design to use an **Arduino** board, which is considerably more familiar to most makers.

This sensor board have equivalent sub-pixel accuracy which came from the *flipper*'s design. It dismisses the calibration button, however