       Serial.println(slit_position);
       updateLED();
     }
-    else if(command=="b") { // set brightness min value
+    else if(equal(command,"brightness")) { // set brightness min value
       // TODO argument check
       // argument is float
       brightness_min = argument.toFloat();

        Serial.println(argument);
      }
    }
    else if(command=="p") { // set position
      // TODO argument check
      // argument is float
      slit_position = argument.toFloat();

      updateLED();
    }
  }
}

bool equal(String str1, String str2) {
  return str1.compareTo(str2)==0;
}

// limitation of brightness
