Non-blocking breathing led for arduino…

Oct 19, 2011

flo

i needed a version of the ‘breathing led’ for a project which would not block everything else. button presses and the actual application should run without delay. after all it would just be cosmetics

the result looks like this:

here is my non-blocking code for a breathing led with arduino:


/*
"Breathing non-blocking sleep LED."
Florian Klien 2011
blog.flo.cx
based on work from Jeremy Saglimbeni (thecustomgeek.com)
*/
#define LED 5 // any PWM led will do
unsigned long status_breathe_time = millis();
int breathe_delay = 10;
boolean breathe_up = true;
int breathe_i = 15;

void setup() { // bring the LED up nicely from being off
  for(i = 0 ; i <= 15; i+=1)
  {
    analogWrite(11, i);
    delay(5);
  }
}

void loop()
{
  nonBlockingBreathe();
  otherImportantNonBlockingStuff();
}

void nonBlockingBreathe(){
  if( (status_breathe_time + breathe_delay) < millis() ){
    analogWrite(LED, breathe_i);
    status_breathe_time = millis();
    if (breathe_up == true){
      if (breathe_i > 150) {
        breathe_delay = 4;
      }
      if ((breathe_i > 125) && (breathe_i < 151)) {
        breathe_delay = 5;
      }
      if (( breathe_i > 100) && (breathe_i < 126)) {
        breathe_delay = 7;
      }
      if (( breathe_i > 75) && (breathe_i < 101)) {
        breathe_delay = 10;
      }
      if (( breathe_i > 50) && (breathe_i < 76)) {
        breathe_delay = 14;
      }
      if (( breathe_i > 25) && (breathe_i < 51)) {
        breathe_delay = 18;
      }
      if (( breathe_i > 1) && (breathe_i < 26)) {
        breathe_delay = 19;
      }
      breathe_i += 1;
      if( breathe_i >= 255 ){
        breathe_up = false;
      }
    }else{
      if (breathe_i > 150) {
        breathe_delay = 4;
      }
      if ((breathe_i > 125) && (breathe_i < 151)) {
        breathe_delay = 5;
      }
      if (( breathe_i > 100) && (breathe_i < 126)) {
        breathe_delay = 7;
      }
      if (( breathe_i > 75) && (breathe_i < 101)) {
        breathe_delay = 10;
      }
      if (( breathe_i > 50) && (breathe_i < 76)) {
        breathe_delay = 14;
      }
      if (( breathe_i > 25) && (breathe_i < 51)) {
        breathe_delay = 18;
      }
      if (( breathe_i > 1) && (breathe_i < 26)) {
        breathe_delay = 19;
      }
      breathe_i -= 1;
      if( breathe_i <= 15 ){
        breathe_up = true;
        breathe_delay = 970;
      }
    }
  }
}

original code came from thecustomgeek.com