How to Make a Dimming Light with Arduino?

1.Introduction
 

A potentiometer is a three-terminal resistor with a sliding or rotating contact that forms an adjustable voltage divider. It works by varying the position of a sliding contact across a uniform resistance. In a potentiometer, the entire input voltage is applied across the whole length of the resistor, and the output voltage is the voltage drop between the fixed and sliding contact.

In this project, we are going to learn how to use Arduino to read the values of the potentiometer, and make a dimming lamp.
 

2.Components Required
 

3.Component Knowledge
 

Adjustable potentiometer:

It is a kind of resistor and an analog electronic component, which has two states of 0 and 1(high level and low level). The analog quantity is different, its data state presents a linear state such as 0 to 1023.
 

4.Read the Potentiometer Value
 

We connect the adjustable potentiometer to the analog pin of Arduino to read its value. Please refer to the following wiring diagram for wiring.

/*
Read_the_adjustable_potentiometer_analog_value
http//www.keyestudio.com
*/
int potpin=A1;// initializes analog PIN A1 of the potentiometer
int val=0;// defines "val" with an initial value of 0
void setup()
{
Serial.begin(9600);// sets baudrate to 9600
}
void loop()
{
val=analogRead(potpin);// reads the analog value of analog PIN A1 and assigns it to "val"
Serial.println(val);// displays the value of "val"
}

Upload the code to the Plus mainboard, connect the wires and power on first. Open the serial monitor, set the baud rate to 9600. When you rotate the potentiometer knob, you can see the displayed value change. After calculation, you can get the corresponding value you need.

Below figure shows the analog value it reads.

5.Circuit Diagram and Wiring Diagram
 

In the last step, we read the value of the potentiometer, and now we need to convert the value of the potentiometer into the brightness of the LED to make a lamp that can adjust the brightness. The wiring diagram is as follows.

6.Code
 

/*
Dimming_light
http//www.keyestudio.com
*/
int potpin=A1;// initializes analog PIN A1 of the adjustable potentiometer
int ledpin=11;// initializes the digital PIN 11
int val=0;// defines "val" with an initial value of 0
void setup()
{
pinMode(ledpin,OUTPUT);// sets digital pin to "output"
Serial.begin(9600);// sets baudrate to 9600
}
void loop()
{
val=analogRead(potpin);// reads the analog value of analog PIN A1 and assigns it to "val"
analogWrite(ledpin,val/4);
Serial.println(val);// displays the value of "val"
}

7.Result
 

Upload the code to the Mainboard, connect the wires and power on first. Then open the serial monitor, set the baud rate to 9600, and the monitor will display the value of potentiometer. When we turn the knob of the potentiometer, the brightness of the LED will change.