// LED雷达扫描效果
int leds[] = {2, 3, 4, 5, 6, 7, 8, 9};  // 8个LED引脚
int numLeds = 8;
int trailLength = 3;  // 拖影长度

void setup() {
  for (int i = 0; i < numLeds; i++) {
    pinMode(leds[i], OUTPUT);
  }
}

void loop() {
  // 从左向右扫描
  for (int pos = 0; pos < numLeds; pos++) {
    // 点亮当前主光点（最亮）
    digitalWrite(leds[pos], HIGH);
    
    // 创建拖影效果：前面几个LED逐渐变暗
    for (int trail = 1; trail <= trailLength; trail++) {
      int trailPos = pos - trail;
      if (trailPos >= 0) {
        // 快速闪烁模拟变暗效果
        digitalWrite(leds[trailPos], HIGH);
        delay(15);
        digitalWrite(leds[trailPos], LOW);
        delay(15);
      }
    }
    
    // 短暂延时后关闭主光点
    delay(50);
    digitalWrite(leds[pos], LOW);
  }
  
  delay(300);  // 扫描间隔
}