Set<BluetoothDevice> pairedDevices = bluetoothAdapter.getBondedDevices();
        ArrayList<String> deviceNames = new ArrayList<>();
        final ArrayList<BluetoothDevice> devices = new ArrayList<>();
        if (pairedDevices.size() > 0) {
            for (BluetoothDevice device : pairedDevices) {
                deviceNames.add(device.getName() + "\n" + device.getAddress());
                devices.add(device);
            }
        } else {
            Toast.makeText(this, "No paired devices found", Toast.LENGTH_SHORT).show();
            return;
        }
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setTitle("Select Bluetooth Device");
        builder.setItems(deviceNames.toArray(new CharSequence[deviceNames.size()]), new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                BluetoothDevice device = devices.get(which);
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
                    if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.BLUETOOTH_CONNECT) != PackageManager.PERMISSION_GRANTED) {
                        ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.BLUETOOTH_CONNECT, Manifest.permission.BLUETOOTH_SCAN}, REQUEST_PERMISSIONS);
                        return;
                    }
                }
                ConnectThread connectThread = new ConnectThread(device);
                connectThread.start();
            }
        });
        builder.show();
    }
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == REQUEST_ENABLE_BT) {
            if (resultCode == RESULT_OK) {
                showPairedDevices();
            } else {
                Toast.makeText(this, "Bluetooth is required to run this application", Toast.LENGTH_LONG).show();
                finish();
            }
        }
        super.onActivityResult(requestCode, resultCode, data);
    }
    private class ConnectThread extends Thread {
        private final BluetoothDevice device;
        public ConnectThread(BluetoothDevice device) {
            BluetoothSocket tmp = null;
            this.device = device;
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
                if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.BLUETOOTH_CONNECT) != PackageManager.PERMISSION_GRANTED) {
                    ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.BLUETOOTH_CONNECT, Manifest.permission.BLUETOOTH_SCAN}, REQUEST_PERMISSIONS);
                    return;
                }
            }
            try {
                tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
            } catch (IOException e) {
                Log.e(TAG, "Socket's create() method failed", e);
            }
            bluetoothSocket = tmp;
        }
        public void run() {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
                if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.BLUETOOTH_CONNECT) != PackageManager.PERMISSION_GRANTED) {
                    ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.BLUETOOTH_CONNECT, Manifest.permission.BLUETOOTH_SCAN}, REQUEST_PERMISSIONS);
                    return;
                }
            }
            bluetoothAdapter.cancelDiscovery();
            try {
                bluetoothSocket.connect();
                manageConnectedSocket();
            } catch (IOException e) {
                try {
                    bluetoothSocket.close();
                } catch (IOException closeException) {
                    Log.e(TAG, "Could not close the client socket", closeException);
                }
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        Toast.makeText(MainActivity.this, "Unable to connect to device. Please try again.", Toast.LENGTH_LONG).show();
                    }
                });
            }
        }
    }
    private void manageConnectedSocket() {
        try {
            inputStream = bluetoothSocket.getInputStream();
            final byte[] buffer = new byte[1024];
            int bytes;
            while (true) {
                try {
                    bytes = inputStream.read(buffer);
                    String readMessage = new String(buffer, 0, bytes).trim();
                    if (readMessage.isEmpty()) {
                        continue;
                    }
                    Log.d(TAG, "Received message: " + readMessage);
                    Message msg = handler.obtainMessage();
                    Bundle bundle = new Bundle();
                    bundle.putString("posture", readMessage);
                    msg.setData(bundle);
                    handler.sendMessage(msg);
                } catch (IOException e) {
                    Log.e(TAG, "Error occurred when reading input stream", e);
                    runOnUiThread(() ->
                            Toast.makeText(MainActivity.this, "Error occurred during communication. Please try again.", Toast.LENGTH_LONG).show());
                    break;
                }
            }
        } catch (IOException e) {
            Log.e(TAG, "Error occurred when creating input stream", e);
            runOnUiThread(() ->
                    Toast.makeText(MainActivity.this, "Error occurred during communication setup. Please try again.", Toast.LENGTH_LONG).show());
        }
    }
    private void showStretchingImages(String posture) {
        int[] stretchImages = getStretchImagesForPosture(posture);
        if (stretchImages == null) {
            return;
        }
        new CountDownTimer(270000, 30000) {
            int index = 0;
            @Override
            public void onTick(long millisUntilFinished) {
                if (index < stretchImages.length) {
                    stretchImageView.setImageResource(stretchImages[index]);
                    index++;
                }
            }
            @Override
            public void onFinish() {
            }
        }.start();
    }
    private int[] getStretchImagesForPosture(String posture) {
        int[] images = null;
        switch (posture) {
            case "GOOD":
                images = new int[]{R.drawable.p1, R.drawable.w1, R.drawable.w2, R.drawable.w3, R.drawable.w4,
                        R.drawable.w5, R.drawable.w6, R.drawable.w7, R.drawable.w8};
                break;
            case "SLIGHT":
                images = new int[]{R.drawable.p2, R.drawable.w9, R.drawable.w10, R.drawable.w11, R.drawable.w12,
                        R.drawable.w13, R.drawable.w14, R.drawable.w15, R.drawable.w16};
                break;
            case "BAD":
                images = new int[]{R.drawable.p3, R.drawable.w17, R.drawable.w18, R.drawable.w19, R.drawable.w20,
                        R.drawable.w21, R.drawable.w22, R.drawable.w23, R.drawable.w24};
                break;
        }
        return images;
    }
}