UnitySerianHandloerのUnity2018で使えたやつ

SerialHandler.cs

using UnityEngine;
using System.Collections;
using System.IO.Ports;
using System.Threading;

public class SerialHandler : MonoBehaviour
{
    public delegate void SerialDataReceivedEventHandler(string message);
    public event SerialDataReceivedEventHandler OnDataReceived = delegate { };

    //ポート名
    //例
    //Linuxでは/dev/ttyUSB0
    //windowsではCOM1
    //Macでは/dev/tty.usbmodem1421など
    public string portName = "/dev/cu.usbmodem2101";//mac
    public int baudRate = 9600;

    private SerialPort serialPort_;
    private Thread thread_;
    private bool isRunning_ = false;

    private string message_;
    private bool isNewMessageReceived_ = false;

    void Awake()
    {
        Open();
    }

    void Update()
    {
        if (isNewMessageReceived_)
        {
            OnDataReceived(message_);
        }
        isNewMessageReceived_ = false;
    }

    void OnDestroy()
    {
        Close();
    }

    private void Open()
    {
        serialPort_ = new SerialPort(portName, baudRate, Parity.None, 8, StopBits.One);
        //または
        //serialPort_ = new SerialPort(portName, baudRate);
        serialPort_.ReadTimeout = 20;//Add this 2019
        serialPort_.Open();
        serialPort_.NewLine = "\n";//Add this 2019

        isRunning_ = true;

        thread_ = new Thread(Read);
        thread_.Start();
    }

    private void Close()
    {
        //isNewMessageReceived_ = false;
        isRunning_ = false;

        if (thread_ != null && thread_.IsAlive)
        {
            thread_.Join();
        }

        if (serialPort_ != null && serialPort_.IsOpen)
        {
            serialPort_.Close();
            serialPort_.Dispose();
        }
    }

    private void Read()
    {
        while (isRunning_ && serialPort_ != null && serialPort_.IsOpen)
        {
            try
            {
                message_ = serialPort_.ReadLine();
                isNewMessageReceived_ = true;
            }
            catch (System.Exception e)
            {
            //    Debug.LogWarning(e.Message);
            }
        }
    }

    public void Write(string message)
    {
        try
        {
            serialPort_.Write(message);
        }
        catch (System.Exception e)
        {
            Debug.LogWarning(e.Message);
        }
    }
}

Unityボタン側スクリプト

Btn.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class Btn : MonoBehaviour
{
    //先ほど作成したクラス
    public SerialHandler serialHandler;


  void Start()
    {
        //信号を受信したときに、そのメッセージの処理を行う
        serialHandler.OnDataReceived += OnDataReceived;
    }

    void Updata()
    {
        //文字列を送信
       // serialHandler.Write("hogehoge");
    }

    //受信した信号(message)に対する処理
    void OnDataReceived(string message)
    {
        var data = message.Split(
                new string[] { "\t" }, System.StringSplitOptions.None);
        if (data.Length < 2) return;

        try
        {
         
        }
        catch (System.Exception e)
        {
            Debug.LogWarning(e.Message);
        }
    }



    /////ここから追加します
    /// 
    /// 
    /// 
    ///
    public void sendOn()
    {
        //Arduinoに文字列onを送る
        serialHandler.Write("4");
    }

    public void sendOff()
    {
        //
        serialHandler.Write("5");
    }
    public void ledOn()
    {
        //
        serialHandler.Write("6");
    }

    public void ledOff()
    {
        //
        serialHandler.Write("7");
    }

}

Arduino側コード

#include <Servo.h>
const int LED_PIN = 13;
int SERVO_SOCKET = 9;
Servo servo;
String InByte_strings;
int InByte;

void setup() {
 Serial.begin(9600);
 pinMode( LED_PIN, OUTPUT );
servo.attach( SERVO_SOCKET );
}

void loop() {
  
  if(Serial.available()>0){
    InByte_strings=Serial.readStringUntil(';');
    InByte=InByte_strings.toInt();
    Serial.println(InByte);

     switch (InByte){
    case 4:
      servo.write( 90 );
      break;
    case 5:
      servo.write( 180 );
      break;
      case 6:
      digitalWrite(LED_PIN,HIGH);
      break;
      case 7:
      digitalWrite(LED_PIN,LOW);
      break;
  }
}
}