Get data from arduino

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3. using System.Timers;
4. using System.IO;
5. using System.IO.Ports;
6. using System.Linq;
7. using System.Threading;
8. using System;
9.  
10. public class PlayerController : MonoBehaviour
11. {
12.     public float speed;
13.     SerialPort sp;
14.     string[] stringDelimiters = new string[] { ":", "R", }; //Items we want to ignore in strings.
15.     public Transform target; //The item we want to affect with our accelerometer
16.     private Rigidbody rb;
17.     bool portFound;
18.     void Start()
19.     {
20.         sp = new SerialPort("COM4");
21.         //sp.PortName = SetPortName(sp.PortName);
22.         sp.DtrEnable = false; //Prevent the Arduino from rebooting once we connect to it.
23.                               //A 10 uF cap across RST and GND will prevent this. Remove cap when programming.
24.         sp.ReadTimeout = 1; //Shortest possible read time out.
25.         sp.WriteTimeout = 1; //Shortest possible write time out.
26.         sp.Open();
27.         rb = GetComponent<Rigidbody>();
28.  
29.         //try
30.         //{
31.             //string[] ports = SerialPort.GetPortNames();
32.             //foreach (string port in ports)
33.             //{
34.                 //sp = new SerialPort(port, 9600);
35.                 //if (ArduinoDetected())
36.                 //{
37.                     //Debug.Log("12");
38.                     //portFound = true;
39.                     //sp.WriteLine("1");
40.                     //break;
41.                 //}
42.                 //else
43.                 //{
44.                     //portFound = false;
45.                     //sp.WriteLine("0");
46.                 //}
47.             //}
48.         //}
49.         //catch
50.         //{
51.         //}
52.  
53.     }
54.     void Update()
55.     {
56.         //if (portFound == true) {
57.        string data = sp.ReadLine();
58.        Console.Write(data);
59.        string[] words = data.Split(new char[] { '/' }, System.StringSplitOptions.RemoveEmptyEntries);
60.        int x = Int32.Parse(words[0]);
61.        Debug.Log(x);
62.        int x1 = Int32.Parse(words[1]);
63.         //float moveHorizontal = Input.GetAxis("Horizontal");
64.         //float moveVertical = Input.GetAxis("Vertical");
65.         //Vector3 movement = new Vector3(x, 0.0f, x1);
66.         //rb.AddForce(movement * speed);
67.         //}
68.     }
69.  
70.     //private bool ArduinoDetected()
71.     //{
72.         //try
73.         //{
74.             //sp.Open();
75.             //System.Threading.Thread.Sleep(1000);
76.             // небольшая пауза, ведь SerialPort не терпит суеты
77.  
78.             //string returnMessage = sp.ReadLine();
79.             //sp.Close();
80.  
81.             // необходимо чтобы void loop() в скетче содержал код Serial.println("Info from Arduino");
82.             //if (returnMessage.Contains("123456"))
83.             //{
84.                 //return true;
85.             //}
86.             //else
87.             //{
88.                 //return false;
89.             //}
90.         //}
91.         //catch
92.         //{
93.             //return false;
94.         //}
95.     //}
96.  
97. }

Unity gives me this error:
TimeoutException: The operation has timed out.
System.IO.Ports.WinSerialStream.Read (System.Byte[] buffer, System.Int32 offset, System.Int32 count) (at <d2957de1c3fd4781a43d89572183136c>:0)
System.IO.Ports.SerialPort.read_byte () (at <d2957de1c3fd4781a43d89572183136c>:0)
System.IO.Ports.SerialPort.ReadTo (System.String value) (at <d2957de1c3fd4781a43d89572183136c>:0)
System.IO.Ports.SerialPort.ReadLine () (at <d2957de1c3fd4781a43d89572183136c>:0)
(wrapper remoting-invoke-with-check) System.IO.Ports.SerialPort.ReadLine()
PlayerController.Update () (at Assets/Scripts/PlayerController.cs:57)

Why i can't assing data from serial port to string?
Maybe somebody know how to autodetect Arduino?
Thank you for help.