Ldr Arduino Light Sensor

The resistance of a photoresistor decreases with an increase in incident light intensity.

Ldr arduino light sensor.

How does it work. We can take advantage of this ldr property and use it in our diy arduino ldr sensor project. As it mainly used in mobiles for auto brightness and smart street lights. When there is light the resistance of ldr will become low according to the intensity of light.

It is associated with both analog output pin and digital output pin labelled as ao and do respectively on the board. Here s how simulation of circuits happen using tinkercad software. It detects the light intensity. This code for the light sensor with arduino enables reading the voltage analog value through the a0 pin of the arduino.

The circuit will output as high when light is detected and low when it s dark. By connecting a pin of the photoresistor to an analog input pin we can read the analog value from the pin by using analogread function and then we can know the light levels relatively. A condition is set for darkness and brightness. Connect the a0 pin of the arduino to the same column where the ldr and resistor is connected since the ldr gives out an analog voltage it is connected to the analog input pin on the arduino.

Arduino s pin a0 to a5 can work as the analog input. The arduino with its built in adc analog to digital converter then converts the analog voltage from 0 5v into a digital value in the range of 0 1023. In order to detect the intensity of light or darkness we use a sensor called an ldr light dependent resistor. To use a dark sensor instead connect lm358 s pin 7 of to one of arduino s digital i o pins.

This analog voltage will be increased or decreased according to the resistance of ldr. From the code above if the value is less than 150 then it is dark and the led turns on. The ldr is a special type of resistor that allows higher voltages to pass through it low resistance whenever there is a high intensity of light and passes a low voltage high resistance whenever it is dark. The greater the intensity of light the lower the resistance of ldr.

Arduino light sensor. We use it to control the lights when there is dark it detects light intensity and blows the lights. The analog input pin converts the voltage between 0v and vcc into integer values between 0 and 1023 called adc value or analog value. Ldr sensor module is used to detect the intensity of light.

A photoresistor ldr is a passive component that decreases resistance with respect to receiving luminosity light on the component s sensitive surface. To work the circuit as a light sensor connect lm358 s pin 1 to one of arduino s digital i o pins. The article gives an overview of light intensity measurement using ldr.