#include <FastLED.h>
#define C_0 -1
#define C_1 262
#define C_2 294
#define C_3 330
#define C_4 350
#define C_5 393
#define C_6 441
#define C_7 495

// 灯带定义
#define LED_PIN     8       
#define NUM_LEDS    16      
CRGB leds[NUM_LEDS];

int yinfu[] = {C_1,C_2,C_3,C_1,C_1,C_2,C_3,C_1,C_3,C_4,C_5,
               C_3,C_4,C_5,C_5,C_6,C_5,C_4,C_3,C_1,C_5,C_6,C_5,C_4,C_3,
               C_1,C_1,C_5,C_1,C_1,C_5,C_1};
float yinpai[] = {1,1,1,1,1,1,1,1,1,1,2,1,1,2,0.75,0.25,0.75,0.25,1,1,
                  0.75,0.25,0.75,0.25,1,1,1,1,2,1,1,2};
int length;
int tonepin = 2;

// 根据音符频率计算亮灯个数
int getLedCount(int note) {
  if (note == C_0) return 0;       
  else if (note <= C_2) return 2; 
  else if (note <= C_4) return 5;  
  else if (note <= C_6) return 9; 
  else return NUM_LEDS;            
}

void setup() {
  pinMode(tonepin, OUTPUT);
  FastLED.addLeds<WS2812, LED_PIN, GRB>(leds, NUM_LEDS); 
  FastLED.setBrightness(50);  
  length = sizeof(yinfu) / sizeof(yinfu[0]);
}

void loop() {
  for (int i = 0; i < length; i++) {  
    int note = yinfu[i];
    int ledCount = getLedCount(note);  
    
    // 更新灯带：前ledCount个灯亮，其余熄灭
    fill_solid(leds, NUM_LEDS, CRGB::Black); 
    for (int j = 0; j < ledCount; j++) {
      leds[j] = CRGB::White;  
    }
    FastLED.show();  
    
    // 播放音符
    if (note != C_0) {  
      tone(tonepin, note);
    }
    delay(400 * yinpai[i]);
    noTone(tonepin);
  }
  
  fill_solid(leds, NUM_LEDS, CRGB::Black);  
  FastLED.show();
  delay(1000);
}