Blinking various LEDs using Arrays

We have already discussed how to blink a single LED, two LEDs, and LEDs using a loop, in previous topics.

Here, we will discuss a project to blink five LEDs using array. All the five LEDs will light one after the other.

Hardware Required

The components required for the project are listed below:

5 x red LED
5 x 220 Ohm Resistors
Arduino UNO R3 board
Jump wires

We can use any color LED as per our choice.

Principle

We will connect the five LEDs to pins 13, 12, 8, 4, and 2 of the Arduino board. The required resistance of the resistors is enough to light up an LED without damaging the board and other components.

The LED arranged one after another will light up. We can also change or rearrange the LEDs connected to the specified pin number on the board.

Structure of the project

The structure clearly shows the UNO board's pinout, and the five LEDs with resistors in series are connected to the board.

It is shown below:

Connection

The connection of the above project is discussed below:

Connect the resistor of 220 Ohm in series with the five LEDs. Now connect it to the pin number 13, 12, 8, 4, and 2 of the Arduino board.
Connect the negative terminal of the five LEDs to the GND (Ground).

Sketch

The code to light the five LEDs is given below:

int timer = 500;           
int LEDPins[] = {13, 12, 8, 4, 2};       // an array of declared pin numbers on the board
int countOFpin = 6;           // the number of arrays
void setup() 
{
  // we have declared an array to intialize the LED pins as OUTPUT
  for (int PIN = 0; PIN < countOFpin; PIN= PIN + 1) 
{
    pinMode(LEDPins[PIN], OUTPUT);
  }
}
void loop()
 {
  // loop starting from the lowest pin in the array to the highest:
  for (int PIN = 0; PIN < countOFpin; PIN++) {
    // turns the pin ON:
    digitalWrite(LEDPins[PIN], HIGH);
    delay(timer);
    // turnS the pin OFF:
    digitalWrite(LEDPins[PIN], LOW);
  }
  // loop from the highest pin in the array to the lowest: 
  // It means the LEDs will light in the reverse direction as used above
  for (int PIN = countOFpin - 1; PIN >= 0; PIN- -)
 { 
    digitalWrite(LEDPins[PIN], HIGH);
    delay(timer);
    digitalWrite(LEDPins[PIN], LOW);
    // We can also specify the time inside the delay( ) instead of the delcaring the timer
  }
}