Need help with my simple LED program :)

Projects Programming
1

Hi there,

I have made a simple LED program with 4 LED's (4 colours) in total. I was able to fade all LED and to apply a delay time to them. The 4 LED will start fading in or out all at the same time. My problem is that I would like to fade the 4 LED independently from each other with their own delay time and I can't see to get this done. I have included my code below, maybe you could give me some useful tips.

I was wondering if the Arduino is able to run more than one program (sketch) at the same time. This would also help resolve this problem since I could set up 4 different independently programs for each of these LED's. Can you please help?

Thank you very much.

Elio.

I am using the Mega 2560 board.

/*
 Fading
 Program created: 
 
 8-Feb-2013 
 */


int ledPin = 12;    // LED connected to digital pin 12
int redPin = 11;    // LED connected to digital pin 11
int bluPin = 10;
int grePin = 9;

void setup()  { 

  // formula here is: 127.5 * (x) = ( x = delay in seconds)
  // fade in from min to max in increments of 2 points:
  for(int fadeValue = 0 ; fadeValue <= 255; fadeValue +=2) { 
    // sets the value (range from 0 to 255):
    analogWrite(ledPin, fadeValue);
    analogWrite(redPin, fadeValue); 
    analogWrite(bluPin, fadeValue);
    analogWrite(grePin, fadeValue);   
    // First stage ramp up taking 4 hours    
    delay(112941);                            
  } 
  
  // formula here is: 3 * (x) = final in seconds ( x = delay in sec) 
  for(int fadeValue = 255 ; fadeValue >= 250; fadeValue -=2) {
    analogWrite(ledPin, fadeValue);
    analogWrite(redPin, fadeValue); 
    analogWrite(bluPin, fadeValue);
    analogWrite(grePin, fadeValue);
    delay(2400000);
  }
  
  for(int fadeValue = 250 ; fadeValue <= 255; fadeValue +=2) {
    analogWrite(ledPin, fadeValue);
    analogWrite(redPin, fadeValue); 
    analogWrite(bluPin, fadeValue);
    analogWrite(grePin, fadeValue);
    delay(2400000);
  }
  
  // fade out from max to min in increments of 2 points:
  for(int fadeValue = 255 ; fadeValue >= 0; fadeValue -=2) { 
    // sets the value (range from 255 to 0):
    analogWrite(ledPin, fadeValue);
    analogWrite(redPin, fadeValue); 
    analogWrite(bluPin, fadeValue);
    analogWrite(grePin, fadeValue);    
    // Last stage ramp down taking 4 hours    
    delay(112941);                            
  }
} 

void loop()  { 
  }
2

Electric:
I was wondering if the Arduino is able to run more than one program (sketch) at the same time. This would also help resolve this problem since I could set up 4 different independently programs for each of these LED's. Can you please help?

You would either need multiple cores (like the Propeller) or an operating system. The Arduino has neither, so in order to multi-task, you'll have to remove code that blocks for an extended period of time. The Blink Without Delay example will get you started. Before attempting anything, I recommend playing around with the example until you fully understand what it is doing.

3
4

Thanks for the link, Nick. Nice explanation. I couldn't have done it better. Karma bump.

5

Hey thanks guys for the help, I really appreciated it :slight_smile: