More Arduino and LED examples

In the first basic tutorial we showed a couple of simple LED examples, here is another couple to try

A reminder of the schematic if you need it

Arduino and LEDs

Code examples
Start up the Arduino IDE, a barebones sketch will appear, delete everything and enter the following

Example 1: Leds on and off – one at a time

[codesyntax lang=”cpp”]

/*
* Blink many LEDs example
* switches an LED on and off one at a time
*/
void setup() 
{
pinMode(2, OUTPUT); // set pin 2 as output
pinMode(3, OUTPUT); 
pinMode(4, OUTPUT); 
pinMode(5, OUTPUT); 
pinMode(6, OUTPUT); 
pinMode(7, OUTPUT); 
pinMode(8, OUTPUT); 
}

void loop() 
{
digitalWrite(2, HIGH);
delay(1000);
digitalWrite(2, LOW); 
delay(1000);
digitalWrite(3, HIGH); 
delay(1000);
digitalWrite(3, LOW); 
delay(1000);
digitalWrite(4, HIGH); 
delay(1000);
digitalWrite(4, LOW); 
delay(1000);
digitalWrite(5, HIGH); 
delay(1000);
digitalWrite(5, LOW); 
delay(1000);
digitalWrite(6, HIGH); 
delay(1000);
digitalWrite(6, LOW); 
delay(1000);
digitalWrite(7, HIGH); 
delay(1000);
digitalWrite(7, LOW); 
delay(1000);
digitalWrite(8, HIGH); 
delay(1000);
digitalWrite(8, LOW); 
delay(1000);
}

[/codesyntax]
Example 2: Switch the LEDs on one a time and then off again

[codesyntax lang=”cpp”]

/*
* Blink many LEDs example
* switches an LED on one at a time then off one at a time
*/
void setup() 
{
pinMode(2, OUTPUT); // set pin 2 as output
pinMode(3, OUTPUT); 
pinMode(4, OUTPUT); 
pinMode(5, OUTPUT); 
pinMode(6, OUTPUT); 
pinMode(7, OUTPUT); 
pinMode(8, OUTPUT); 
}

void loop() 
{
digitalWrite(2, HIGH);
delay(1000);
digitalWrite(3, HIGH);
delay(1000);
digitalWrite(4, HIGH); 
delay(1000);
digitalWrite(5, HIGH); 
delay(1000);
digitalWrite(6, HIGH); 
delay(1000);
digitalWrite(7, HIGH); 
delay(1000);
digitalWrite(8, HIGH); 
delay(1000); 
digitalWrite(2, LOW);
delay(1000);
digitalWrite(3, LOW);
delay(1000);
digitalWrite(4, LOW); 
delay(1000);
digitalWrite(5, LOW); 
delay(1000);
digitalWrite(6, LOW); 
delay(1000);
digitalWrite(7, LOW); 
delay(1000);
digitalWrite(8, LOW); 
delay(1000); 
}

[/codesyntax]

Example 3 : All on the All off

[codesyntax lang=”cpp”]

/*
* Blink many LEDs example
* switches all LEDs on then off
*/
void setup() 
{
pinMode(2, OUTPUT); // set pin 2 as output
pinMode(3, OUTPUT); 
pinMode(4, OUTPUT); 
pinMode(5, OUTPUT); 
pinMode(6, OUTPUT); 
pinMode(7, OUTPUT); 
pinMode(8, OUTPUT); 
}

void loop() 
{
digitalWrite(2, HIGH);
digitalWrite(3, HIGH);
digitalWrite(4, HIGH); 
digitalWrite(5, HIGH); 
digitalWrite(6, HIGH); 
digitalWrite(7, HIGH); 
digitalWrite(8, HIGH); 
delay(1000); 
digitalWrite(2, LOW);
digitalWrite(3, LOW);
digitalWrite(4, LOW); 
digitalWrite(5, LOW); 
digitalWrite(6, LOW); 
digitalWrite(7, LOW); 
digitalWrite(8, LOW); 
delay(1000); 
}

[/codesyntax]

Of course there are better ways of doing the examples above, we will show you these soon