How to Use a Zener Diode as a Light Sensor / A Little Alternative Electronics Knowledge 😊 - YouTube
Diymore 4pin Lm393 Light Sensor Switch Module Digital Photosensitive Diode Detection Switch Board For Arduino Raspberry Pi Dc 5v - Integrated Circuits - AliExpress
uxcell Photosensitive Diode Sensor Light Detection Photodiode Module with Digital and Analog Output for Smart Car 3pcs: Amazon.com: Industrial & Scientific
Photo Transistor Light Sensor : ID 2831 : $0.95 : Adafruit Industries, Unique & fun DIY electronics and kits
Read photo-diode / resistor as a digital value - General Electronics - Arduino Forum