We tried flashing one LED, now it’s time to try not flashing multiple LEDs simultaneously, but with different light sequences. This circuit is also a nice setup to experiment with writing your own programs and to get a feel for how Arduino works.
Along with controlling the LEDs we start looking into a few simple programming methods to keep your programs small.
Hardware Used:
- 5 – LED
You can buy all this Hardware at Createlabz.
Software Used:
Set up the Hardware:

Code:
/* ---------------------------------------------------------
* | Arduino Experimentation Kit Example Code |
* | CIRC-02 .: 5 LED Fun :. (Multiple LEDs) |
* ---------------------------------------------------------
*
* A few Simple LED animations
*
* For more information on this circuit http://tinyurl.com/d2hrud
*
*/
//LED Pin Variables
int ledPins[] = {2,3,4,5,6}; //An array to hold the pin each LED is connected to
//i.e. LED #0 is connected to pin 2, LED #1, 3 and so on
//to address an array use ledPins[0] this would equal 2
/*
* setup() - this function runs once when you turn your Arduino on
* We the three control pins to outputs
*/
void setup()
{
//Set each pin connected to an LED to output mode (pulling high (on) or low (off)
for(int i = 0; i < 8; i++){ //this is a loop and will repeat eight times
pinMode(ledPins[i],OUTPUT); //we use this to set each LED pin to output
} //the code this replaces is below
/* (commented code will not run)
* these are the lines replaced by the for loop above they do exactly the
* same thing the one above just uses less typing
pinMode(ledPins[0],OUTPUT);
pinMode(ledPins[1],OUTPUT);
pinMode(ledPins[2],OUTPUT);
pinMode(ledPins[3],OUTPUT);
pinMode(ledPins[4],OUTPUT);
}
/*
* loop() - this function will start after setup finishes and then repeat
* we call a function called oneAfterAnother(). if you would like a different behaviour
* uncomment (delete the two slashes) one of the other lines
*/
void loop() // run over and over again
{
oneAfterAnotherNoLoop(); //this will turn on each LED one by one then turn each off
//oneAfterAnotherLoop(); //does the same as oneAfterAnotherNoLoop but with
//much less typing
//oneOnAtATime(); //this will turn one LED on then turn the next one
//on turning the
//former off (one LED will look like it is scrolling
//along the line
//pingPong();
//randomLED();
}
/*
* oneAfterAnotherNoLoop() - Will light one LED then delay for delayTime then light
* the next LED until all LEDs are on it will then turn them off one after another
*
* this does it without using a loop which makes for a lot of typing.
* oneOnAtATimeLoop() does exactly the same thing with less typing
*/
void oneAfterAnotherNoLoop(){
int delayTime = 100; //the time (in milliseconds) to pause between LEDs
//make smaller for quicker switching and larger for slower
digitalWrite(ledPins[0], HIGH); //Turns on LED #0 (connected to pin 2 )
delay(delayTime); //waits delayTime milliseconds
digitalWrite(ledPins[1], HIGH); //Turns on LED #1 (connected to pin 3 )
delay(delayTime); //waits delayTime milliseconds
digitalWrite(ledPins[2], HIGH); //Turns on LED #2 (connected to pin 4 )
delay(delayTime); //waits delayTime milliseconds
digitalWrite(ledPins[3], HIGH); //Turns on LED #3 (connected to pin 5 )
delay(delayTime); //waits delayTime milliseconds
digitalWrite(ledPins[4], HIGH); //Turns on LED #4 (connected to pin 6 )
delay(delayTime); //waits delayTime milliseconds
//Turns Each LED Off
digitalWrite(ledPins[4], LOW); //Turns on LED #3 (connected to pin 5 )
delay(delayTime); //waits delayTime milliseconds
digitalWrite(ledPins[3], LOW); //Turns on LED #4 (connected to pin 6 )
delay(delayTime); //waits delayTime milliseconds
digitalWrite(ledPins[2], LOW); //Turns on LED #5 (connected to pin 7 )
delay(delayTime); //waits delayTime milliseconds
digitalWrite(ledPins[1], LOW); //Turns on LED #6 (connected to pin 8 )
delay(delayTime); //waits delayTime milliseconds
digitalWrite(ledPins[0], LOW); //Turns on LED #7 (connected to pin 9 )
delay(delayTime); //waits delayTime milliseconds
}
/*
* oneAfterAnotherLoop() - Will light one LED then delay for delayTime then light
* the next LED until all LEDs are on it will then turn them off one after another
*
* this does it using a loop which makes for a lot less typing.
* than oneOnAtATimeNoLoop() does exactly the same thing with less typing
*/
void oneAfterAnotherLoop(){
int delayTime = 100; //the time (in milliseconds) to pause between LEDs
//make smaller for quicker switching and larger for slower
//Turn Each LED on one after another
for(int i = 0; i <= 5; i++){
digitalWrite(ledPins[i], HIGH); //Turns on LED #i each time this runs i
delay(delayTime); //gets one added to it so this will repeat
} //8 times the first time i will = 0 the final
//time i will equal 7;
//Turn Each LED off one after another
for(int i = 5; i >= 0; i--){ //same as above but rather than starting at 0 and counting up
//we start at seven and count down
digitalWrite(ledPins[i], LOW); //Turns off LED #i each time this runs i
delay(delayTime); //gets one subtracted from it so this will repeat
} //8 times the first time i will = 7 the final
//time it will equal 0
}
/*
* oneOnAtATime() - Will light one LED then the next turning off all the others
*/
void oneOnAtATime(){
int delayTime = 100; //the time (in milliseconds) to pause between LEDs
//make smaller for quicker switching and larger for slower
for(int i = 0; i <= 5; i++){
int offLED = i - 1; //Calculate which LED was turned on last time through
if(i == 0) { //for i = 1 to 7 this is i minus 1 (i.e. if i = 2 we will
offLED = 5; //turn on LED 2 and off LED 1)
} //however if i = 0 we don't want to turn of led -1 (doesn't exist)
//instead we turn off LED 7, (looping around)
digitalWrite(ledPins[i], HIGH); //turn on LED #i
digitalWrite(ledPins[offLED], LOW); //turn off the LED we turned on last time
delay(delayTime);
}
}
/*
* inAndOut() - This will turn on the two middle LEDs then the next two out
* making an in and out look
*/
void pingPong()
{
int index;
int delayTime = 100; // milliseconds to pause between LEDs
// make this smaller for faster switching
// step through the LEDs, from 0 to 7
for(index = 0; index <= 5; index++)
{
digitalWrite(ledPins[index], HIGH); // turn LED on
delay(delayTime); // pause to slow down
digitalWrite(ledPins[index], LOW); // turn LED off
}
// step through the LEDs, from 7 to 0
for(index = 5; index >= 0; index--)
{
digitalWrite(ledPins[index], HIGH); // turn LED on
delay(delayTime); // pause to slow down
digitalWrite(ledPins[index], LOW); // turn LED off
}
}
/*
randomLED()
This function will turn on random LEDs. Can you modify it so it
also lights them for random times?
*/
void randomLED()
{
int index;
int delayTime;
// The random() function will return a semi-random number each
// time it is called. See http://arduino.cc/en/Reference/Random
// for tips on how to make random() even more random.
index = random(5); // pick a random number between 0 and 7
delayTime = 100;
digitalWrite(ledPins[index], HIGH); // turn LED on
delay(delayTime); // pause to slow down
digitalWrite(ledPins[index], LOW); // turn LED off
}
Code Breakdown:
oneAfterAnotherNoLoop(); //oneAfterAnotherLoop(); //oneOnAtATime(); //pingPong(); //randomLED();
The code shown above is a function.
Other codes that was shown here were explained in the blinking LED and if you want to know more about functions just click the link. https://startingelectronics.org/software/arduino/learn-to-program-course/15-functions/
Try MORE!!!!!
Extra animations:
Tired of one animation? Try the other sample animations. Just remove the // and upload the program to your arduino and enjoy the new light! (note: In the loop, 3 must have the // so that it would work!)
The post Arduino Starter’s Guide (2/7): Controlling Multiple LEDs appeared first on CreateLabz.
