diff --git a/gui/main.py b/gui/main.py
index a51197e..4970e42 100644
--- a/gui/main.py
+++ b/gui/main.py
@@ -153,8 +153,8 @@ class PHControllerGUI(QMainWindow):
             self.set_controls_enabled(True)
             
             # Request initial data
-            self.send_command("<114>")  # Request pH value
-            self.send_command("<113>")  # Request tube size
+            self.send_command("<14>")  # Request pH value
+            self.send_command("<13>")  # Request tube size
         except Exception as e:
             QMessageBox.critical(self, "Fehler", f"Verbindungsfehler: {str(e)}")
     
@@ -186,23 +186,23 @@ class PHControllerGUI(QMainWindow):
     
     def send_pump_command(self, state):
         if state == 1:
-            self.send_command("<111>")  # Pump on
+            self.send_command("<11>")  # Pump on
             self.pump_status.setText("Pumpe: Ein")
         else:
-            self.send_command("<112>")  # Pump off
+            self.send_command("<12>")  # Pump off
             self.pump_status.setText("Pumpe: Aus")
     
     def send_tube_command(self, index):
         # The Arduino expects the tube index (0-25)
-        self.send_command(f"<11{index+3}>")  # <11[3-28]>
+        self.send_command(f"<1{index+3}>")  # <11[3-28]>
     
     def send_calibration_command(self, ph):
         if ph == 4:
-            self.send_command("<114>")  # Start pH4 calibration
+            self.send_command("<15>")  # Start pH4 calibration
             QMessageBox.information(self, "Kalibrierung", 
                                    "pH4 Kalibrierung gestartet. Sensor in pH4-Lösung tauchen und warten bis der Wert stabil ist.")
         else:
-            self.send_command("<115>")  # Start pH7 calibration
+            self.send_command("<16>")  # Start pH7 calibration
             QMessageBox.information(self, "Kalibrierung", 
                                    "pH7 Kalibrierung gestartet. Sensor in pH7-Lösung tauchen und warten bis der Wert stabil ist.")
     
diff --git a/ph_controller/ph_controller.ino b/ph_controller/ph_controller.ino
index a6e6c3f..ca4bab8 100644
--- a/ph_controller/ph_controller.ino
+++ b/ph_controller/ph_controller.ino
@@ -136,7 +136,7 @@ int read_LCD_buttons(){                        // read the buttons
 int hys = 1;        // Hysterese zur Messwertglättung
 int lcv = 0;
 
-void reading(){                                   // Reading LM35 and PH Data
+int reading(){                                   // Reading LM35 and PH Data
    // Samplin LM35 and PH Value
   //TempTotal= TempTotal - TempReadings[Index];    // subtract the last reading:       
   PhTotal= PhTotal - PhReadings[Index];          // subtract the last reading:       
@@ -248,41 +248,39 @@ if (Serial.available()) {
       }
     }
   }
-if (RxCmd[1] == '1') {
+if ( RxCmd[1] == '1' ){
   switch (RxCmd[2]) {
-    case '1': // Pump on
-      pinMode(MOTOR1, HIGH);
-      pinMode(MOTOR2, HIGH);
-      Pumpe = 2;
-      Serial.println("<P1>"); // Bestätigung
+    case '1':{ // Pumpe an
+          pinMode(MOTOR1,HIGH);
+          pinMode(MOTOR2,HIGH);
+          Pumpe=2;
       break;
-    case '2': // Pump off
-      pinMode(MOTOR1, HIGH);
-      pinMode(MOTOR2, LOW);
-      Pumpe = 1;
-      Serial.println("<P0>"); // Bestätigung
+    }
+    case '2':{ // Pumpe aus
+          pinMode(MOTOR1,HIGH);
+          pinMode(MOTOR2,LOW);
+          Pumpe=1;
       break;
-    case '3': // Tube selection (3-28)
-      tubid = RxCmd[3] - '3'; // Convert to 0-25
-      if (tubid >= 0 && tubid <= MAXTUB) {
-        EEPROM.put(ee_tubid, tubid);
-        Serial.print("<T");
-        Serial.print(tubid);
-        Serial.println(">"); // Bestätigung
-      }
+    }
+    case '3':{ // Schlauchdaten anfordern
+      Serial.print('<');
+      Serial.print('#');
+      double mlpersec =( ml[tubid]*korrf*2)/6;          // tube * 20 Um/min * korecturfaktor durch 60 sec
+      mlpersec = mlpersec*100000;
+      Serial.print(mlpersec);                          // Return PH Data
+     
+      Serial.println('>');      
       break;
-    case '4': // Send pH value
-      Serial.print("<#");
-      Serial.print(PhValue, 2);
-      Serial.println(">");
-      break;
-    case '5': // Start calibration (4 or 7)
-      // Implement calibration mode
+    }
+    case '4':{// PH - Daten anfordern
+      Serial.print('<');
+      Serial.print(PhValue,2);                          // Return PH Data
+      Serial.println('>');
       break;
+    }
   }
-}
-
 
+}  
 
 
 
@@ -507,7 +505,7 @@ if (CurrentMode == 12) { // Auto modus stopped
           CurrentMode = 0;
           break;
         }
-      
+      }
       case btnSELECT:{
         if (CurrentMode == 0){ // Automodus starten
               pinMode(MOTOR1,HIGH);
@@ -530,7 +528,88 @@ if (CurrentMode == 12) { // Auto modus stopped
       }
     }
    }
-   }
-
+//  if (adc_key_prev != lcd_key)
+//   {
+//   //Serial.println("Key Press Change Detected");
+//   switch (lcd_key){               // depending on which button was pushed, we perform an action
+//       case btnRIGHT:{             //  push button "RIGHT" and show the word on the screen
+//            //lcd.print("RIGHT");
+//            if ( CurrentMode == 0 ){
+//               lcd.clear();
+//               CurrentMode = 2;
+//             }
+//            if ( CurrentMode == 3){
+//               lcd.clear();
+//               if ( CalSelect == 0 ){
+//                 CurrentMode = 4;
+//               } 
+//               if ( CalSelect == 1){
+//                 CurrentMode = 5;
+//               }
+//            }
+//            break;
+//       }
+//       case btnLEFT:{
+//             //lcd.print("LEFT "); //  push button "LEFT" and show the word on the screen
+//             if ( CurrentMode == 2 ){
+//               lcd.clear();
+//               CurrentMode = 0;
+//             }
+//             if ( CurrentMode == 3 ){
+//               lcd.clear();
+//               CurrentMode = 0;
+//             }
+//             if ( CurrentMode == 4 || CurrentMode == 5 ){
+//               lcd.clear();
+//               CurrentMode = 3;
+//             }
+//
+//             break;
+//       }    
+//       case btnUP:{
+//             //lcd.print("UP   ");  //  push button "UP" and show the word on the screen
+//             if ( CurrentMode == 0 ){
+//               lcd.clear();
+//               CurrentMode = 1;
+//             }
+//             if ( CurrentMode == 3 ){
+//               lcd.clear();
+//               CalSelect = 0;
+//             }
+//             break;
+//       }
+//       case btnDOWN:{
+//             //lcd.print("DOWN ");  //  push button "DOWN" and show the word on the screen
+//             if ( CurrentMode == 1){
+//               lcd.clear();
+//               CurrentMode = 0;
+//             }
+//             if ( CurrentMode == 3 ){
+//               lcd.clear();
+//               CalSelect = 1;
+//             }
+//             break;
+//       }
+//       case btnSELECT:{
+//             //lcd.print("SEL. ");  //  push button "SELECT" and show the word on the screen
+//             if ( CurrentMode == 0 ){
+//               lcd.clear();
+//               CurrentMode = 3;
+//               break;
+//             }
+//             if ( CurrentMode == 3 ){
+//               lcd.clear();
+//               CurrentMode = 0;
+//               break;
+//             }
+//               break;
+//
+//       }
+//       case btnNONE:{
+//             //lcd.print("NONE ");  //  No action  will show "None" on the screen
+//             break;
+//       }
+//     }
+//   }
 
 }