PulseLED.ino

#define LED_PIN 9

void setup() {
  pinMode(LED_PIN, OUTPUT);
}

void loop() {
  pulseLED();
//   breatheLED();
}

void pulseLED() {
  float val = 128.0 + 128 * sin((millis() / 1000.0) * PI);
  analogWrite(LED_PIN, val);
}

void breatheLED() {
  float val = (exp(sin(millis() / 2000.0 * PI)) - 0.36787944) * 108.0;
  analogWrite(LED_PIN, val);
}