I want to do is via a serial port to send data to the arduino unity but don't know where is the data unity has not just run to the read data
Below is a program on the arduino;

 
Const int sensorPin=0; 
Int t; 

Void setup () 
{
Serial. The begin (19200); 
PinMode (sensorPin, INPUT); 

} 

Void loop () {
T=analogRead (sensorPin)/4; 
If (t<10) 
{
Serial. Write (1); 
Serial. Println (1); 
Serial. Flush (); 
delay(500); } 
If (t>=10) 
{
Serial. Write (2); 
Serial. Println (2); 
Serial. Flush (); 
delay(500); }} 

The unity of the program

 using System. The Collections; 
Using System. Collections. Generic; 
Using UnityEngine; 
Using System. IO. Ports; 
Using UnityEngine. UI; 

Public class change: MonoBehaviour {
Public GameObject lightA; 
//Use this for initialization 
SerialPort sp=new SerialPort (" COM4 ", 19200); 

Void the Start () {
Sp. The Open (); 
Sp. ReadTimeout=1; 


} 

//Update is called once per frame 
Void the Update () {
If (sp. IsOpen) {

Try {
LightA. GetComponent (a). The text="test";//this is my used to test the sentences on the ReadByte (before) will run on the back will not, ask the great spirit guide 
Changelight (sp. ReadByte ()); 

Print (sp. ReadByte ()); 

} 
The catch (System. Exception) {

} 
} 
} 
Void changelight (int state) 
{if (state==1) 
{
LightA. GetComponent (a). The text="0"; 
} 
If (state==2) {
LightA. GetComponent (a). The text="1"; 
} 
} 
}