       case T_MINUTE:
         setTime(hour(), getNextMinSecFromCurrentMinSec(minute(), true), second(), day(), month(), year());
         break;
+      case T_VOLTAGE:
+        showVoltage = !showVoltage;
+        break;
       default: 
         break;
 

  if(currentState == NORMAL){   
    if(showLCD){
      LowPower.powerDown(SLEEP_15Ms, ADC_OFF, BOD_OFF);
    }else {
      LowPower.powerDown(SLEEP_FOREVER, ADC_OFF, BOD_OFF);
    }


      if(settingTimeProcess == T_HOUR){
        settingTimeProcess = T_MINUTE;
      } 
      else if(settingTimeProcess == T_MINUTE){
        settingTimeProcess = T_VOLTAGE;
      }
      else {
        currentState = NORMAL;
      }
