#include <Adafruit_NeoPixel.h>
#ifdef __AVR__
  #include <avr/power.h>
#endif

#define PIN 23
#define BUTTON_PIN 16

// Parameter 1 = number of pixels in strip
// Parameter 2 = Arduino pin number (most are valid)
// Parameter 3 = pixel type flags, add together as needed:
//   NEO_KHZ800  800 KHz bitstream (most NeoPixel products w/WS2812 LEDs)
//   NEO_KHZ400  400 KHz (classic 'v1' (not v2) FLORA pixels, WS2811 drivers)
//   NEO_GRB     Pixels are wired for GRB bitstream (most NeoPixel products)
//   NEO_RGB     Pixels are wired for RGB bitstream (v1 FLORA pixels, not v2)
//   NEO_RGBW    Pixels are wired for RGBW bitstream (NeoPixel RGBW products)
Adafruit_NeoPixel strip = Adafruit_NeoPixel(16, PIN, NEO_GRB + NEO_KHZ800);

// 初始化亮度
int brightness = 100;

// 上一次按钮状态
int lastButtonState = HIGH;

void adjustBrightness() {
  int buttonState = digitalRead(BUTTON_PIN);

  // 如果按钮被按下并且上一次未被按下，则调整亮度
  if (buttonState == LOW && lastButtonState == HIGH) {
    brightness -= 20;
    if (brightness < 20) {
      brightness = 100;
    }

    // 设置NeoPixel的亮度
    strip.setBrightness(brightness);
    strip.show();
  }

  // 更新上一次按钮状态
  lastButtonState = buttonState;
}

// 递进渐变
void colorWipe(uint32_t c, uint8_t wait) {
  for(uint16_t i=0; i<strip.numPixels(); i++) {
    strip.setPixelColor(i, c);
    strip.show();
    delay(wait);
  }
}

// 输入一个值0到255以获取颜色值
uint32_t Wheel(byte WheelPos) {
  WheelPos = 255 - WheelPos;
  if(WheelPos < 85) {
    return strip.Color(255 - WheelPos * 3, 0, WheelPos * 3);
  }
  if(WheelPos < 170) {
    WheelPos -= 85;
    return strip.Color(0, WheelPos * 3, 255 - WheelPos * 3);
  }
  WheelPos -= 170;
  return strip.Color(WheelPos * 3, 255 - WheelPos * 3, 0);
}

// 单色
void Color(uint32_t color) {
  for (uint16_t i = 0; i < strip.numPixels(); i++) {
    strip.setPixelColor(i, color);
  }
  strip.show();
}

// 彩虹
void rainbow(uint8_t wait) {
  uint16_t i, j;

  for(j=0; j<256; j++) {
    for(i=0; i<strip.numPixels(); i++) {
      strip.setPixelColor(i, Wheel((i+j) & 255));
    }
    strip.show();
    delay(wait);
  }
}

// 清空所有像素
void clear() {
  for(uint16_t i=0; i<strip.numPixels(); i++) {
    strip.setPixelColor(i, 0);
  }
  strip.show();
}

void setup() {
  // This is for Trinket 5V 16MHz, you can remove these three lines if you are not using a Trinket
  #if defined (__AVR_ATtiny85__)
    if (F_CPU == 16000000) clock_prescale_set(clock_div_1);
  #endif
  // End of trinket special code

  strip.begin();
  strip.setBrightness(brightness);
  strip.show(); // Initialize all pixels to 'off'

  // 设置按钮引脚为输入
  pinMode(BUTTON_PIN, INPUT);
}

void loop() {
  // 调整亮度函数
  //adjustBrightness();

  // 递进渐变效果
  //colorWipe(strip.Color(255, 0, 0), 20); // 红色
  //delay(500);

  // 单色效果（修改Color函数的参数即可）
  Color(strip.Color(0, 255, 0)); // 绿色
  delay(500);

  // 彩虹效果
  //rainbow(20);
  //delay(500);

  // 清空所有像素
  clear();
  //delay(500);
}