▷ Control the brightness of an LED using a potentiometer - Arduino

In this post, we will see how to control (vary) the brightness of an LED using an Arduino Uno as a microcontroller, a potentiometer, and an LED.

MATERIALS:

The materials we will use for this project are as follows:

• 1 Arduino Uno.
• 1 Potentiometer (Any value).
• 1 220 Ohm resistor.
• 1 LED (Any color).

WIRING DIAGRAM:

EXPLANATION OF THE FUNCTIONING:

For this project, the LED must be connected to a PWM pin and the potentiometer to an analog pin.

To control the brightness of the LED, we modify the PWM value. We modify the PWM value with the values given by the potentiometer.

Initially, the potentiometer connected to an analog pin gives us values ranging from 0 to 1024; in this case, we need values from 0 to 255. To obtain these values, we use the map() function.

map() function:

This function is widely used in Arduino projects, as it allows us to "make equivalences" between different ranges.

The structure of this function is as follows:

pwm = map(value I receive, inmin, inmax, outmin, outmax);

• pwm:Variable that stores the values returned by the map function.
• value I receive: Value we read from the analog pin.
• inmin:Minimum value delivered by the analog pin.
• inmax:Maximum value delivered by the analog pin.
• outmin:Minimum value that the variable will takepwm.
• outmax:Maximum value that the variable will takepwm.

CODE:

#define led 3 // Pin where the led is connected
#define pot A0 // Pin where the potentiometer is connected
 
void setup() {
 pinMode(led,OUTPUT); // We declare inputs and outputs
 pinMode(pot,INPUT);
}
 
void loop() {
  int pwm; // We declare a variable, in this variable we store the values that the map function gives us
  pwm = map(analogRead(pot), 0, 1024, 0, 255);
  analogWrite(led,pwm); // We turn on the led with the pwm value that the map function sends us
  delay(100); // we add a small pause
}