SunFounder ESP32 Starter Kit
5.25 Photoresistor
A photoresistor or photocell is a light-controlled variable resistor. The resistance of a photoresistor decreases with
increasing incident light intensity; in other words, it exhibits photo conductivity.
A photoresistor can be applied in light-sensitive detector circuits and light-activated and dark-activated switching cir-
cuits acting as a resistance semiconductor. In the dark, a photoresistor can have a resistance as high as several megaohms
(M), while in the light, a photoresistor can have a resistance as low as a few hundred ohms.
Here is the electronic symbol of photoresistor.
• Photoresistor - Wikipedia
Example
• 5.7 Feel the Light (Arduino Project)
• 6.6 Plant Monitor (Arduino Project)
• 5.7 Feel the Light (MicroPython Project)
• 6.8 Plant Monitor (MicroPython Project)
742 Chapter 5. Learn about the Components in Your Kit