 #define BRIGHTNESS_MIN 0.5 // 平常時のBrightness
 float brightness = 1;
 
+int divide = 2; // LEDパターンの分割数
+float slit_position = 0.5; // 0~1 分割された区分の中のどこまでがinstrumentにするか。0だと全部effect color。1だと全部instrument color。
+
 void setup() {
   strip.begin();
   strip.show(); // Initialize all pixels to 'off'

}

void updateLED() {
  uint32_t instrument_color = multiplicateBrightness(i_color_r, i_color_g, i_color_b);
  uint32_t effect_color = multiplicateBrightness(e_color_r, e_color_g, e_color_b);
  for(uint16_t i=0; i<strip.numPixels(); i++) {
    if(i<TOTAL_PIXELS/4){
      strip.setPixelColor(i, instrument_color);
    }
    else if(i<TOTAL_PIXELS/2){
      strip.setPixelColor(i, effect_color);
    }
    else if(i<TOTAL_PIXELS*3/4){
      strip.setPixelColor(i, instrument_color);
    }
    else {
      strip.setPixelColor(i, effect_color);
    }
  }
  strip.show();

    }
    else if(command=="s") { // sound trigger
      brightness = 1.0;
    }
    else if(command=="d") { // set divide number
      
      if(argument.length()==1) {
        // argument is int
        divide = argument.toInt();
        Serial.print("set divide number: ");
        Serial.println(divide);
        updateLED();
      }
      else {
        Serial.print("Invalid argument: ");
        Serial.println(argument);
      }
    }
    else if(command=="l") { // set slit position
      // TODO argument check
      // argument is float
      slit_position = argument.toFloat();
      Serial.print("set slit position: ");
      Serial.println(slit_position);
      updateLED();
    }
    else {
      Serial.print("Command not found: ");
