// Soft pulse (breathing) for COB LED filaments
// XIAO ESP32-S3 Sense · GPIO1 · AO3400 MOSFET

const int PWM_PIN     = 4;      // 
const int PWM_FREQ    = 24989;   // 1kHz — good for pulsing
const int PWM_RES     = 8;      // 8-bit: 0–255
const int BREATHE_MS  = 3000;   // full cycle duration (ms)

void setup() {
  ledcAttach(PWM_PIN, PWM_FREQ, PWM_RES);
}

void loop() {
  // Fade IN
  for (int i = 0; i <= 255; i++) {
    ledcWrite(PWM_PIN, i);
    delay(BREATHE_MS / 2 / 255);
  }

  // Fade OUT
  for (int i = 255; i >= 0; i--) {
    ledcWrite(PWM_PIN, i);
    delay(BREATHE_MS / 2 / 255);
  }
}