https://hackaday.io/project/204465-adding-numbers-using-photoresistors-and-led/
4 bit adder made using AND, OR, XOR gates which were made with Photoresistors and LEDs.
addingnumbersusingphotoresistorsled
https://www.instructables.com/Arduino-SOLAR-TRACKER-Using-Photoresistors-and-a-S/
Arduino - SOLAR TRACKER Using Photoresistors and a Servo: Hello world! Today i build a solar tracker with a mini solar panel a servo and 2 Photoresistors....
solar trackerarduinousingphotoresistorsservo