bdwidth sensor is an optical width and motion sensor for 3D printer.
Feature:
Adjust the flow rate in real time
Pause the printer while the filament jams and runout
 Width accuracy: +/- 0.015mm
 Connection: USB port or I2C port
 No calibration required
 Firmware update from the usb
Package list:
bdwidth sensor
1.3 meter i2c cable
1.5 meter usb type-c cable
 
Note：
Transparent filament: It cannot measure the width of fully transparent filaments, but it can still measure movement. This means that the jam and runout detection functions still work
 
Source: 
https://github.com/markniu/bdwidth
 
Video: 
https://youtu.be/Cj5bzoDzowE