Blinking LED Arduino

updated 21 April 2022

This is a blinking LED activity as the intro for Arduino Code programming.

The Arduino Code

Arduino is both software and hardware. Right there, you can control your design (hardware) through the code (software). So, it's one of the reasons also that Arduino is used extensively in prototyping.

There are two built-in functions in Arduino Code: void setup and void loop.

void setup is where you tell the computer whether an electronic component being programmed is an output device. Other initial setup can be done here, like the initial mode of an LED is turned on.

void loop is where the execution of commands happens. Take note, void loop is a repeat forever loop.

Take note of the word void. A void type of function will simply execute all the commands and will not return any value. Other functions which are not void do return values.

The Setup

You need 3 basic LEDs, 3 resistors, 1 breadboard and the Arduino UNO board.

Follow the setup as shown in the picture below:

Then, go to Code section and copy the initial code below:

void setup()
{
  pinMode(13, OUTPUT);
  pinMode(12, OUTPUT);
  pinMode(11, OUTPUT);
}

void loop()
{
  digitalWrite(13, HIGH);
  digitalWrite(12, LOW);
  digitalWrite(11, LOW);
  delay(1000);
  
  digitalWrite(13, LOW);
  digitalWrite(12, HIGH);
  digitalWrite(11, LOW);
  delay(1000);
  
  digitalWrite(13, LOW);
  digitalWrite(12, LOW);
  digitalWrite(11, HIGH);
  delay(1000);
}

Code Explanation

There are just 3 commands being used here:

pinMode is the command you tell the Arduino board what is the mode of a particular pin. If not, then the default is input.

digitalWrite is the command whether there will be supply of voltage HIGH or there is none LOW for a particular pin, like in our example, Arduino Digital Pin 13. For a basic LED, we all know that when there is sufficient voltage, it is turned on and if there is too low or none at all, it is turned off.

delay is the command for temporarily delaying a program, just like a pause. If prior to this, an LED is turned on, it will pause for a certain amount of time with the initial status of the LED. It's in terms of milliseconds, because for computers, they work in terms of milliseconds or even nanoseconds. For example, they can accomplish, say, a thousand tasks in just 1 second. For high-powered servers, it's more than that. For advanced programmers, this is very critical: it can be used for multitasking, say, that 1 second delay can be used to do other tasks within the main program.

Now, talking about the initial code above, it will simply have blinking LEDs from right to left and the interval is 1 second. And since it is a repeat forever loop, it will simply continue doing the same thing until you stop it.

You can modify the code to blink at the same time or another pattern with rhythm by changing the delay at different parts. As you can see, you have the full control through your code, as long as you know how to modify it without breaking it.

Finally, here is the actual project link:

https://www.tinkercad.com/things/achHRTDWDhW

Related Project

You may want additional information about the Arduino UNO board, the breadboard and another project, so check this out:

https://github.com/xdvrx1/single-display-arduino-project