Introduction: Control an LED With PWM Output
As you may have noticed in the Arduino board (Uno, Mega-etc.) Are present some PIN that have next a symbol like a wave.
This symbol indicates that the output can also be used in "PWM" or "Pulse-width modulation".
Using this function, it is possible to vary, for example, the frequency of switching on and off of an LED.
Step 1: The Circuit
First we need to:
- Arduino Uno
- A resistor 220Ohm
- A LED
- Breadboard
- Wires for links
Mounted the circuit as described in the picture
Step 2: The Sketch
// Created by //
// Alessio Bigini 2015 //
// http://alessiobigini.it //
int lum = 0;
void setup()
{
pinMode(9, OUTPUT);
}
void loop()
{
for (lum = 0; lum < 255; lum++ )
{
analogWrite(9, lum);
delay(10);
}
for (lum = 255; lum > 0; lum-- )
{
analogWrite(9, lum);
delay(10);
}
}
Now load the sketch into your board
In this code I used two simple For loops that allow me to increase the variable "Lum" from 0 to 255 and then decrease it.
