Interrupciones del procesador con Arduino

				
					/*
Example: Interrupting an LED sequence
SparkFun Electronics
Follow the tutorial at: 
https://learn.sparkfun.com/tutorials/processor-interrupts-with-arduino#example-interrupting-an-led-sequence
This code is released under the MIT License (http://opensource.org/licenses/MIT)
******************************************************************************/
// Cycling through a series of colors using the built-in LED on the LilyPad USBPlus. Using an interrupt to switch quickly between colors
// The built-in LED:
int RGB_red = 12;
int RGB_green = 13;
int RGB_blue = 14;
int x = 0;  // variable to be updated by the interrupt
//Fade variables
int ledMode = 0; //color mode to control LEDs
int colorSwitch = 0; //compare to current_FadeVal to know whether or not to switch colors yet
int prev_FadeVal = 0;
int current_FadeVal = 0;
boolean increasing = true;
//variables to keep track of the timing of recent interrupts
unsigned long button_time = 0;  
unsigned long last_button_time = 0; 

void setup() {
// Make all of our LED pins outputs:
  pinMode(RGB_red, OUTPUT);
  pinMode(RGB_green, OUTPUT);
  pinMode(RGB_blue, OUTPUT);
  attachInterrupt(0, increment, CHANGE);
  Serial.begin(9600);  //turn on serial communication
}
void loop()
{
  // In this code we'll step through seven rainbow colors (primary, secondary, tertiary).
  // Unlike digitalWrite, which can be only HIGH (on) or LOW (off),
  // analogWrite lets you smoothly change the brightness from 0 (off) to 255 (fully on).
  // When analogWrite is used with the RGB LED, you can create millions of colors!
  
  FadeColor();
}
// Interrupt service routine for interrupt 0
void increment() {
  button_time = millis();
  
  //check to see if increment() was called in the last 250 milliseconds
  if (button_time - last_button_time > 250)
  {
    //increment counter
    x++;
    //turn led off
    analogWrite(RGB_red,0);
    analogWrite(RGB_green,0); 
    analogWrite(RGB_blue,0);
  
    Serial.println(x, DEC); //print x to serial monitor
    delay(10000);
    //set the last button time to the current button time
    last_button_time = button_time;
    //Switch colors    
    if (ledMode < 7){
      ledMode++;
    }
    else {
      //start over with Red
      ledMode = 1;
    }
    //reset fade values
    prev_FadeVal = 0;
    current_FadeVal = 0;
  
  }
}
void FadeColor() {
  switch (ledMode) {
    case 1://FADE RED
      analogWrite(RGB_green, 0);
      analogWrite(RGB_blue, 0);
      analogWrite(RGB_red, prev_FadeVal);
      break;
    case 2://FADE YELLOW
      analogWrite(RGB_red, prev_FadeVal);
      analogWrite(RGB_green, prev_FadeVal);
      analogWrite(RGB_blue, 0);
      break;
    case 3://FADE GREEN
      analogWrite(RGB_red, 0);
      analogWrite(RGB_green, prev_FadeVal);
      analogWrite(RGB_blue, 0);
      break;
    case 4://FADE CLEAR BLUE
      analogWrite(RGB_red, 0);
      analogWrite(RGB_green, prev_FadeVal);
      analogWrite(RGB_blue, prev_FadeVal);
      break;
    case 5://FADE BLUE
      analogWrite(RGB_red, 0);
      analogWrite(RGB_green, 0);
      analogWrite(RGB_blue, prev_FadeVal);
      break;
    case 6://FADE MAGENTA
      analogWrite(RGB_red, prev_FadeVal);
      analogWrite(RGB_green, 0);
      analogWrite(RGB_blue, prev_FadeVal);
      break;
      
    default:
      analogWrite(RGB_red, prev_FadeVal);
      analogWrite(RGB_green, prev_FadeVal);
      analogWrite(RGB_blue, prev_FadeVal);
      break;
  }
  delay(100);
  if (increasing == true) {
    current_FadeVal += 5;
  }
  else { //decreasing
    current_FadeVal -= 5;
  }
  if (current_FadeVal > 255) {
    increasing = false;
    prev_FadeVal -= 5;//undo addition
    current_FadeVal = prev_FadeVal;
  }
  else if (current_FadeVal < 0) {
    increasing = true;
    prev_FadeVal += 5;//unto subtraction
    current_FadeVal = prev_FadeVal;
  }
  prev_FadeVal = current_FadeVal;
  if(current_FadeVal == colorSwitch)
  {
    if (ledMode < 7){
      ledMode++;
    }
    else {
      //start over with Red
      ledMode = 1;
    }
  }
}