// 定义连接LED的引脚，确保这些是支持PWM的引脚
int ledPins[] = {10, 9, 6}; 
int ledDelay = 10; // 呼吸灯变化的延迟时间，单位毫秒
int brightnessStep = 5; // 亮度每次改变的步长

void setup() {
  // 初始化每个LED引脚为输出模式
  for (int i = 0; i < 3; i++) {
    pinMode(ledPins[i], OUTPUT);
  }
}

void loop() {
  // 对每个LED进行呼吸效果
  for (int i = 0; i < 3; i++) {
    // 逐渐变亮
    for (int brightness = 0; brightness <= 255; brightness += brightnessStep) {
      analogWrite(ledPins[i], brightness);
      delay(ledDelay);
    }
    // 逐渐变暗
    for (int brightness = 255; brightness >= 0; brightness -= brightnessStep) {
      analogWrite(ledPins[i], brightness);
      delay(ledDelay);
    }
  }
}