       Serial.println(slit_position);
       updateLED();
     }
-    // set brightness min value
+    // set instrument_brightness min value
     // "b:[0.0-1.0];"
     else if(command=="b") {
       // TODO argument check
       // argument is float
-      brightness_min = argument.toFloat();
-      Serial.print("set brightness min value: ");
-      Serial.println(brightness_min);
+      instrument_brightness_min = argument.toFloat();
+      Serial.print("set instrument_brightness min value: ");
+      Serial.println(instrument_brightness_min);
       updateLED();
     }
     else {

  strip.show();
}

uint32_t multiplicateBrightness(int _r, int _g, int _b) {
  int r = (int) _r*brightness;
  int g = (int) _g*brightness;
  int b = (int) _b*brightness;
  return strip.Color(r, g, b);
}


}

void updateLED() {
  uint32_t instrument_color = multiplicateBrightness(constrainValue(i_color_r), constrainValue(i_color_g), constrainValue(i_color_b), instrument_brightness);
  uint32_t effect_color = multiplicateBrightness(constrainValue(e_color_r), constrainValue(e_color_g), constrainValue(e_color_b), effect_brightness);

  switch (i_type) {

