Не удается найти код, который подключает мой модуль Arduino Bluetooth (Android Studio)

Question

Я пытаюсь создать приложение для Android, которое может отправлять письма в Arduino уже несколько месяцев. Я новичок в программировании Android, и я действительно не могу найти какие-либо рабочие фрагменты кода для "части соединения". Я могу включать и выключать Bluetooth, обнаруживать устройства и даже показывать связанные. Они отображаются в виде списка, и я хочу коснуться устройства в списке, и оно подключится к моему телефону.

Мой проект до сих пор:

ConnectActiviy.java:

package timelabs.com.btcar;

import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.Intent;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.util.Log;
import android.view.View;
import android.support.v4.view.GravityCompat;
import android.support.v7.app.ActionBarDrawerToggle;
import android.view.MenuItem;
import android.support.design.widget.NavigationView;
import android.support.v4.widget.DrawerLayout;

import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.reflect.Array;
import java.util.ArrayList;
import java.util.Set;
import java.util.UUID;

public class ConnectActivity extends AppCompatActivity
        implements NavigationView.OnNavigationItemSelectedListener {

    // Variablen
    private BluetoothAdapter BA = null;

        public void findDiscoverableDevices(View view){

            Intent i = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
            startActivity(i);

        }

        public void turnBluetoothOff(View view){

            BA.disable();

            if(BA.isEnabled()){
                Toast.makeText(getApplicationContext(), "Bluetooth could not be disabled", Toast.LENGTH_SHORT).show();
            }else{
                Toast.makeText(getApplicationContext(), "Bluetooth turned Off", Toast.LENGTH_SHORT).show();
            }
        }

        public void viewPairedDevices(View view){

            Set <BluetoothDevice> pairedDevices = BA.getBondedDevices();

            ListView pairedDevicesListView = (ListView)findViewById(R.id.pairedDevicesListView);

            ArrayList pairedDevicesArrayList = new ArrayList();

            for (BluetoothDevice bluetoothDevice: pairedDevices){

                pairedDevicesArrayList.add(bluetoothDevice.getName());
            }

            ArrayAdapter arrayAdapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1, pairedDevicesArrayList);
            pairedDevicesListView.setAdapter(arrayAdapter);
        }





    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_connect);
        Toolbar toolbar = findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        DrawerLayout drawer = findViewById(R.id.drawer_layout);
        NavigationView navigationView = findViewById(R.id.nav_view);
        ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
                this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
        drawer.addDrawerListener(toggle);
        toggle.syncState();
        navigationView.setNavigationItemSelectedListener(this);

        //BLUETOOTH

        BA = BluetoothAdapter.getDefaultAdapter();

        if(BA.isEnabled()){

            Toast.makeText(getApplicationContext(), "Bluetooth On", Toast.LENGTH_SHORT).show();

        }else{

            Intent i = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
            startActivity(i);

            if(BA.isEnabled()){
                Toast.makeText(getApplicationContext(), "Bluetooth turned On", Toast.LENGTH_SHORT).show();
            }
        }







    }

    @Override
    public void onBackPressed() {
        DrawerLayout drawer = findViewById(R.id.drawer_layout);
        if (drawer.isDrawerOpen(GravityCompat.START)) {
            drawer.closeDrawer(GravityCompat.START);
        } else {
            super.onBackPressed();
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.connect, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    @SuppressWarnings("StatementWithEmptyBody")
    @Override
    public boolean onNavigationItemSelected(MenuItem item) {
        // Handle navigation view item clicks here.
        int id = item.getItemId();

        if (id == R.id.nav_remote) {

            Intent goto_main = new Intent(ConnectActivity.this,
                    MainActivity.class);
            startActivity(goto_main);

        } else if (id == R.id.nav_connect) {

        } else if (id == R.id.nav_1) {

        } else if (id == R.id.nav_2) {

        } else if (id == R.id.nav_rate) {

        } else if (id == R.id.nav_feedback) {

        }

        DrawerLayout drawer = findViewById(R.id.drawer_layout);
        drawer.closeDrawer(GravityCompat.START);
        return true;
    }
}

content_connect.xml:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context=".ConnectActivity"
    tools:showIn="@layout/app_bar_connect">

    <Button
        android:id="@+id/buttonOff"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:layout_marginBottom="8dp"
        android:onClick="turnBluetoothOff"
        android:text="Turn BT Off"
        app:layout_constraintBottom_toTopOf="@+id/pairedDevicesListView"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/findDiscoverableDevicesButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginBottom="8dp"
        android:onClick="findDiscoverableDevices"
        android:text="Find Discoverable Devices"
        app:layout_constraintBottom_toTopOf="@+id/pairedDevicesListView"
        app:layout_constraintEnd_toStartOf="@+id/viewPairedDevicesButton"
        app:layout_constraintStart_toEndOf="@+id/buttonOff"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/viewPairedDevicesButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginBottom="8dp"
        android:onClick="viewPairedDevices"
        android:text="View Paired Devices"
        app:layout_constraintBottom_toTopOf="@+id/pairedDevicesListView"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <ListView
        android:id="@+id/pairedDevicesListView"
        android:layout_width="715dp"
        android:layout_height="283dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginBottom="8dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.875" />
</android.support.constraint.ConstraintLayout>

AndroidManifest.xml:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="timelabs.com.btcar">

    <uses-permission android:name="android.permission.BLUETOOTH"/>
    <uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity
            android:name=".ConnectActivity"
            android:label="@string/title_activity_connect"
            android:screenOrientation="sensorLandscape"
            android:theme="@style/AppTheme.NoActionBar"></activity>
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name"
            android:screenOrientation="sensorLandscape"
            android:theme="@style/AppTheme.NoActionBar">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

Мой план - провести 2 мероприятия. Одним из них является мой ConnectActivity, который отвечает за управление подключением Bluetooth, а MainActivity - это мой пульт, который будет отправлять письма в Arduino.