micro:bit（マイクロビット）と拡張基盤とUnityで遊んでみる ref: https://qiita.com/Sase/items/6a316da26f512b36217a

ObjRotation.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using AppKit;
using System.Text;

public class ObjContllol : MonoBehaviour {
    ArduinoSerial serial;
    Vector3 rotation;
    public string portNum;
    public Transform rotationObj;
    public string massage;

    enum MOVE_STATE
    {
        UP,
        DOWN,
        LEFT,
        RIGHT,
    }

    void Start()
    {
        serial = ArduinoSerial.Instance;
        bool success = serial.Open(portNum, ArduinoSerial.Baudrate.B_115200);
        if (!success)
        {
            return;
        }
        serial.OnDataReceived += SerialCallBack;
    }
    void OnDisable()
    {
        serial.Close();
        serial.OnDataReceived -= SerialCallBack;
    }
    // Update is called once per frame
    void Update () {
    }

    void SerialCallBack(string m)
    {
        objMove (m);
        objRotation(m);
        massage = m;
    }

    void objRotation(string message)
    {
        string[] a;

        a = message.Split("="[0]);
        if(a.Length != 2) return;  
        int v = int.Parse( a[1]);
        switch(a[0])
        {
        case "pitch":
            rotation = new Vector2(v, rotation.y);
            break;
        case "roll":
            rotation = new Vector2( rotation.x, v);
            break;
        }
        Quaternion AddRot = Quaternion.identity;
        AddRot.eulerAngles = new Vector3( -rotation.x, 0, -rotation.y );

        transform.rotation = AddRot;
    }

    void objMove(string message)
    {
        string[] a;

        a = message.Split("="[0]);
        if(a.Length != 2) return;  
        int v = int.Parse( a[1]);
        string m = a [0];
        if (m == "button") {

            string mc = a [1];

            //a_button
            if (mc [0] == '1') {
                print ("a_button");
            }
            //b_button
            if (mc [1] == '1') {
                print ("b_button");
            }
//          //y_button
            if (mc [2] == '1') {
                print ("y_button");
                rotationObj.GetComponent<Renderer> ().material.color = Color.blue;
            }
            //x_button
            if (mc [3] == '1') {
                print ("x_button");
                rotationObj.GetComponent<Renderer> ().material.color = Color.red;
            }
            //up
            if (mc [4] == '1') {
                print ("up");
                transform.SetPositionAndRotation (transform.position + (Vector3.up * 0.05f), transform.rotation);
                rotationObj.GetComponent<Renderer> ().material.color = Color.green;
            }
            //dawn
            if (mc [5] == '1') {
                print ("dawn");
                transform.SetPositionAndRotation (transform.position + (Vector3.down * 0.05f), transform.rotation);
                rotationObj.GetComponent<Renderer> ().material.color = Color.magenta;
            }
            //left
            if (mc [6] == '1') {
                print ("left");
                transform.SetPositionAndRotation (transform.position + (Vector3.left * 0.05f), transform.rotation);
                rotationObj.GetComponent<Renderer> ().material.color = Color.yellow;
            }
            //right
            if (mc [7] == '1') {
                print ("right");
                transform.SetPositionAndRotation (transform.position + (Vector3.right * 0.05f), transform.rotation);
                rotationObj.GetComponent<Renderer> ().material.color = Color.cyan;
            }

        }
    }

    void OnTriggerEnter(Collider co)
    {
        Destroy (co.gameObject);
        serial.Write ("ITEM");
        Debug.LogError("item_get");
    }
}