The photoresistor is based on light resistance, it will sense the light and will allow the microcontroller in this case Arduino to react and change the intensity of Led Diode. The photoresistor ...

It looks simple enough – a 64-LED ... photoresistor, but found it was a bit too slow for matrix scanning. An LM358 op-amp is used to get the signal up to a reasonable level for an Arduino Uno ...

I only had the Arduino UNO board and a couple of LEDs so this project was not tested completly ... It must be an optocoupler with photoresistor or LDR output.

Arduino has launched its next generation of UNO boards, introducing a 32-bit Renesas microcontroller and Espressif ESP32-S3 module, one-click cloud connectivity and plenty of I/O plus a 12×8 red LED ...