How to operate LDR using Arduino Uno

A light-dependent resistor (LDR) is the light-sensitive device most frequently used to measure the intensity of light. Light-dependent resistors are also known as photoresistors whose resistance increases as the intensity of light decreases which helps to identify the presence and absence of light.

If the resistance is high that means it’s dark (less light) but if some light falls on LDR then this resistance reduces rapidly which describes that there is enough brightness (more light). Hence photoresistors are used as the light detector in applications such as Automatic Street lighting systems, security systems, light intensity meters, burglar alarm systems, and camera shutter control.

I have made two advanced-level projects using LDR which are a Smart plant watering system using Arduino Uno and a Locker guard based on Arduino Uno.

In this article I will explain to you, how can you use a light-dependent resistor with Arduino Uno using digital and analog inputs. In the first example, I will explain to you how an LED can be operated with the help of the light-dependent resistor with the help of analog input pins.

In the second example, I will explain to you the same project with digital input pins. I will use the same circuit connection (except for the inputs) for both examples which will help you to understand the concept in a very easy way.

How to operate LED using LDR with Arduino Uno (using analog input):

How to operate LED using LDR with Arduino Uno (using digital input):

For more detail please visit:

https://arduinounomagic.com/how-to-operate-ldr-using-arduino-uno/