Public Inventions

Optical Linear Sensor

Isometric Veiw.PNG


This project was conducted under Public Inventions, an open source company founded by Dr. Robert Read. The goal of the project was to create a distance sensor using light instead of conventional methods so that, in theory, the sensor could shrink infinitesimally or be unbounded by size in large scale. 



The existing structure consisted of a 3D printed tube with precise cut outs for the LED and Cds Cell . A CdS photoresistor (photocell) was attached to a 100K resistor in series and a 5 volts source and a white LED was attached to a 560 resistor in series a 3.3 V source. The photocell was placed in a 1 cm black tubing and both the photocell housing and the LED were placed at one end of the plastic tubing and black electrical tape was used to secure them and to prevent light from entering the tube. A 1 cm black rode with 2 white caps on either ends was placed in a 3D printed sliding holster so it could slide back and forth from end to end.

An overview video of the project can be viewed below.


Meet The Team


Keeshan Patel

Electrical/Computer Engineering Student


Robert L. Read, PhD

Founder of Public Inventions