How Do I Activate The Switch Statement

OK I have been at this for hours, I can receive the characters into Unity through the serial port from the Arduino but HOW do I get them to activate my switch statement at the bottom of the script.

// Update is called once per frame
	void Update () {
		/*string dataFromArduinoString = sp.ReadLine ();
		int dFAI = int.Parse (dataFromArduinoString);
		print (dFAI);
		DirectionArrow (dFAI);*/

		try
		{
			//DirectionArrow(sp.ReadByte());
			//print(sp.ReadByte());
			/*string dataFromArduinoString = sp.ReadLine ();
			int dFAI = int.Parse (dataFromArduinoString);
			print (dFAI);
			DirectionArrow (dFAI);*/
			string message3 = sp.ReadLine(); //get the message...
			if(message3 == ""); //if its empty stop right here
			print(message3);
			DirectionArrow (message3);
			///////////
			/// CALL  THIS TO THE SWITCH CASE BOTTOM OF SCRIPT.... HOW DO I DO THAT??
			///////////
		}
		catch (System.Exception) {

		}
			//print("BytesToRead" +sp.BytesToRead);
			message2 = sp.ReadLine();
			
		string message = sp.ReadLine(); //get the message...
		if(message == "") return; //if its empty stop right here
		// parse the input to a float and normalize it (range 0..1) (we could do this already in the Arduino)

		float input =  1 -  float.Parse (message) / 100f;
		// set the slider to the value
		float oldValue = slider.value; // -------- this is new
		slider.value = input;

		// after the slider is updated, we can check for the other things for example play sounds:

		if (source.isPlaying) return; // if we are playing a sound stop here

		// else check if we need to play a sound and do it
		if (slider.value > 0.9f && oldValue <= 0.9f) // ---------this has changed
			source.PlayOneShot (BrightnessAudioClips [Random.Range (0, BrightnessAudioClips.Length)]);

		else if (slider.value < 0.15f && oldValue >= 0.15f) //----------this has changed
			source.PlayOneShot (DarknessAudioClips [Random.Range (0, DarknessAudioClips.Length)]);
		

	}


void DirectionArrow(string buttonStatus)
	{
		
	switch (buttonStatus)
	{
		//OFF Buttons  States
		case "O":
			//deactivate Left Direction Arrow
			SystemGuidanceManagerScript WAOff = FindObjectOfType<SystemGuidanceManagerScript>();
			WAOff.WestArrowOff ();

			SystemGuidanceManagerScript EAOff = FindObjectOfType<SystemGuidanceManagerScript>();
			EAOff.EastArrowOff();

			SystemGuidanceManagerScript SFXOff = FindObjectOfType<SystemGuidanceManagerScript>();
			SFXOff.TopIndicatorOff();

			SystemGuidanceManagerScript BGSOff = FindObjectOfType<SystemGuidanceManagerScript>();
			BGSOff.BarLEDsSounderOff();
			break;
		//LEFT BUTTON ON STATE
		case "W":
			//Activate Left Direction Arrow Indicator
			SystemGuidanceManagerScript WAOn = FindObjectOfType<SystemGuidanceManagerScript>();
			WAOn.WestArrow();

			SystemGuidanceManagerScript WBSOn = FindObjectOfType<SystemGuidanceManagerScript>();
			WBSOn.BarLEDsSounderOn();
			break;
		//RIGHT BUTTON ON STATE
		case "E":
			//Activate Right Direction Arrow Indicator
			SystemGuidanceManagerScript EAOn = FindObjectOfType<SystemGuidanceManagerScript> ();
			EAOn.EastArrow ();

			SystemGuidanceManagerScript EBSOn = FindObjectOfType<SystemGuidanceManagerScript>();
			EBSOn.BarLEDsSounderOn();
			break;
	}
			
	}

I bet that your “E” character is returning with the linefeed or carriage return.

At line 19, do this:

DirectionArrow (message3.Trim());

Your other issues should probably be in a new question, after you accept this answer.