diff --git a/android/ConductorsPhone/app/build.gradle b/android/ConductorsPhone/app/build.gradle
index d208ac1..993b6df 100644
--- a/android/ConductorsPhone/app/build.gradle
+++ b/android/ConductorsPhone/app/build.gradle
@@ -8,10 +8,11 @@ android {
     compileSdkVersion 26
     defaultConfig {
         applicationId "de.tonifetzer.conductorswatch"
-        minSdkVersion 23
+        minSdkVersion 24
         targetSdkVersion 26
-        versionCode 1
-        versionName "1.0"
+        //sdk 2 | product version 3 | build num 2 | multi-apk 2
+        versionCode 260120100
+        versionName "0.1.2"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
     }
     buildTypes {
@@ -20,6 +21,10 @@ android {
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
         }
     }
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
 }
 
 dependencies {
diff --git a/android/ConductorsPhone/app/src/main/AndroidManifest.xml b/android/ConductorsPhone/app/src/main/AndroidManifest.xml
index 4bf6a67..4c4f298 100644
--- a/android/ConductorsPhone/app/src/main/AndroidManifest.xml
+++ b/android/ConductorsPhone/app/src/main/AndroidManifest.xml
@@ -2,6 +2,9 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="de.tonifetzer.conductorswatch">
 
+    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
+    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
+
     <application
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"
@@ -16,6 +19,7 @@
         <service android:name=".DataLayerListenerService">
             <intent-filter>
                 <action android:name="com.google.android.gms.wearable.MESSAGE_RECEIVED" />
+                <action android:name="com.google.android.gms.wearable.CHANNEL_EVENT" />
                 <data android:scheme="wear" android:host="*" android:pathPrefix="/start-activity"/>
             </intent-filter>
         </service>
diff --git a/android/ConductorsPhone/app/src/main/java/de/tonifetzer/conductorswatch/DataFolder.java b/android/ConductorsPhone/app/src/main/java/de/tonifetzer/conductorswatch/DataFolder.java
new file mode 100644
index 0000000..1d4f446
--- /dev/null
+++ b/android/ConductorsPhone/app/src/main/java/de/tonifetzer/conductorswatch/DataFolder.java
@@ -0,0 +1,57 @@
+package de.tonifetzer.conductorswatch;
+
+/**
+ * Created by toni on 12/01/18.
+ */
+
+import android.content.Context;
+import android.os.Environment;
+import android.util.Log;
+
+import java.io.File;
+
+/**
+ * Class: DataFolder
+ * Description: SDK save file class. Is able to open a folder on the device independent of the given
+ * device and android skd version.
+ */
+public class DataFolder {
+
+    private File folder;
+    private static final String TAG = "DataFolder";
+
+    public DataFolder(Context context, String folderName){
+
+        // 1) try external data folder
+        folder = new File(context.getExternalFilesDir(Environment.DIRECTORY_DOCUMENTS), folderName);
+        if (isOK(folder)) {return;}
+
+        // 2) try sd-card folder
+        folder = new File(Environment.getExternalStorageDirectory() + "/" + folderName);
+        if (isOK(folder)) {return;}
+
+        // 3) try internal data folder
+        folder = new File(context.getApplicationInfo().dataDir);
+        if (isOK(folder)) {return;}
+
+        // all failed
+        throw new RuntimeException("failed to create/access storage folder");
+
+    }
+
+    /** ensure the given folder is OK */
+    private static final boolean isOK(final File folder) {
+        folder.mkdirs();
+        final boolean ok =  folder.exists() && folder.isDirectory();
+        if (ok) {
+            Log.d(TAG, "using: " + folder);
+        } else {
+            Log.d(TAG, "not OK: " + folder);
+        }
+        return ok;
+    }
+
+    public File getFolder(){
+        return folder;
+    }
+}
diff --git a/android/ConductorsPhone/app/src/main/java/de/tonifetzer/conductorswatch/DataLayerListenerService.java b/android/ConductorsPhone/app/src/main/java/de/tonifetzer/conductorswatch/DataLayerListenerService.java
index 821daa3..755bc37 100644
--- a/android/ConductorsPhone/app/src/main/java/de/tonifetzer/conductorswatch/DataLayerListenerService.java
+++ b/android/ConductorsPhone/app/src/main/java/de/tonifetzer/conductorswatch/DataLayerListenerService.java
@@ -3,10 +3,17 @@ package de.tonifetzer.conductorswatch;
 import android.content.Intent;
 import android.util.Log;
 import com.google.android.gms.common.api.GoogleApiClient;
+import com.google.android.gms.wearable.ChannelClient;
 import com.google.android.gms.wearable.MessageEvent;
 import com.google.android.gms.wearable.Wearable;
 import com.google.android.gms.wearable.WearableListenerService;
 
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
 /**
  * Listens to DataItems and Messages from the local node.
  */
@@ -14,6 +21,7 @@ public class DataLayerListenerService extends WearableListenerService {
 
     private static final String TAG = "DataLayerService";
     private static final String START_ACTIVITY_PATH = "/start-activity";
+    private static final String DATA_PATH ="/data";
 
     GoogleApiClient mGoogleApiClient;
 
@@ -28,7 +36,7 @@ public class DataLayerListenerService extends WearableListenerService {
 
     @Override
     public void onMessageReceived(MessageEvent messageEvent) {
-        //LOGD(TAG, "onMessageReceived: " + messageEvent);
+        LOGD(TAG, "onMessageReceived: " + messageEvent);
 
         // Check to see if the message is to start an activity
         if (messageEvent.getPath().equals(START_ACTIVITY_PATH)) {
@@ -43,4 +51,40 @@ public class DataLayerListenerService extends WearableListenerService {
             Log.d(tag, message);
         }
     }
+
+    @Override
+    public void onOutputClosed(ChannelClient.Channel openChannel, int i, int i1){
+
+        LOGD(TAG, "Channel successfully opened.");
+
+        //get the sensordata provided by the watch
+        Wearable.getChannelClient(this).getInputStream(openChannel).addOnSuccessListener((InputStream stream) -> {
+
+            Log.d(TAG, "Channel successfully opened and ready to write file.");
+
+            byte[] data = null;
+            try {
+                stream.read(data);
+                DataFolder folder = new DataFolder(this, "sensorOutFiles");
+                File file = new File(folder.getFolder(), System.currentTimeMillis() + ".csv");
+
+                try {
+                    FileOutputStream fos = new FileOutputStream(file);
+                    fos.write(data);
+                    fos.close();
+
+                } catch (FileNotFoundException e) {
+                    e.printStackTrace();
+                }
+
+            } catch (IOException e) {
+                e.printStackTrace();
+            }
+        }).addOnFailureListener((Exception e) -> {
+            //Channel not open? couldn't receive inputstream?
+        });
+
+        //we have what we wanted, so close the channel
+        Wearable.getChannelClient(this).close(openChannel);
+    }
 }
\ No newline at end of file
diff --git a/android/ConductorsPhone/app/src/main/java/de/tonifetzer/conductorswatch/MainActivity.java b/android/ConductorsPhone/app/src/main/java/de/tonifetzer/conductorswatch/MainActivity.java
index 735697b..b813237 100644
--- a/android/ConductorsPhone/app/src/main/java/de/tonifetzer/conductorswatch/MainActivity.java
+++ b/android/ConductorsPhone/app/src/main/java/de/tonifetzer/conductorswatch/MainActivity.java
@@ -1,22 +1,25 @@
 package de.tonifetzer.conductorswatch;
 
+import android.app.Activity;
 import android.graphics.Color;
-import android.media.MediaPlayer;
 import android.support.v7.app.AppCompatActivity;
 import android.os.Bundle;
 import android.util.Log;
-import android.view.SoundEffectConstants;
+import android.widget.EditText;
 import android.widget.TextView;
+import com.google.android.gms.wearable.ChannelClient;
 import com.google.android.gms.wearable.MessageEvent;
 import com.google.android.gms.wearable.MessageClient;
 import com.google.android.gms.wearable.Wearable;
-
 import java.util.Timer;
 
+import de.tonifetzer.conductorswatch.network.SensorDataCallback;
+
 public class MainActivity extends AppCompatActivity implements MessageClient.OnMessageReceivedListener{
 
     private TextView mTextView;
-    Timer mTimer;
+    private EditText mEditView;
+    private Timer mTimer;
 
     private static final String TAG = "DataLayerService";
     private static final String START_ACTIVITY_PATH = "/start-activity";
@@ -26,27 +29,34 @@ public class MainActivity extends AppCompatActivity implements MessageClient.OnM
 
     private boolean mIsRecording = false;
 
+    private ChannelClient.ChannelCallback mChannelCallback;
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
 
-        mTextView = (TextView) findViewById(R.id.bpmText);
+        mTextView = findViewById(R.id.bpmText);
+        mEditView = findViewById(R.id.comments);
+
+        // handels everything regarding sensor data delivered by the watch.
+        mChannelCallback = new SensorDataCallback(this);
     }
 
     @Override
     public void onResume() {
         super.onResume();
         Wearable.getMessageClient(this).addListener(this);
+        Wearable.getChannelClient(this).registerChannelCallback(mChannelCallback);
     }
 
     @Override
     protected void onPause() {
         super.onPause();
         Wearable.getMessageClient(this).removeListener(this);
+        Wearable.getChannelClient(this).unregisterChannelCallback(mChannelCallback);
     }
 
-
     @Override
     public void onMessageReceived(MessageEvent messageEvent) {
 
@@ -67,6 +77,8 @@ public class MainActivity extends AppCompatActivity implements MessageClient.OnM
                 mTimer = new Timer();
                 mTimer.scheduleAtFixedRate(new Metronome(this) , 0, 60000 / Integer.parseInt(parts[1]));
                 mTextView.setTextColor(Color.parseColor("#EE693F"));
+                mEditView.setEnabled(false);
+                mEditView.setFocusable(false);
                 mIsRecording = true;
             }
 
@@ -75,6 +87,9 @@ public class MainActivity extends AppCompatActivity implements MessageClient.OnM
 
             mTimer.cancel();
             mTextView.setTextColor(Color.parseColor("#158b69"));
+            mEditView.setEnabled(true);
+            mEditView.setFocusable(true);
+            mEditView.setFocusableInTouchMode(true);
             mIsRecording = false;
         }
         else if (messageEvent.getPath().contains(UPDATE_PATH)){
diff --git a/android/ConductorsPhone/app/src/main/java/de/tonifetzer/conductorswatch/network/SensorDataCallback.java b/android/ConductorsPhone/app/src/main/java/de/tonifetzer/conductorswatch/network/SensorDataCallback.java
new file mode 100644
index 0000000..1f2ecd9
--- /dev/null
+++ b/android/ConductorsPhone/app/src/main/java/de/tonifetzer/conductorswatch/network/SensorDataCallback.java
@@ -0,0 +1,68 @@
+package de.tonifetzer.conductorswatch.network;
+
+import android.content.Context;
+import android.support.annotation.NonNull;
+import android.util.Log;
+
+import com.google.android.gms.wearable.ChannelClient;
+import com.google.android.gms.wearable.Wearable;
+
+import java.io.InputStream;
+
+/**
+ * Created by toni on 14/01/18.
+ */
+
+public class SensorDataCallback extends ChannelClient.ChannelCallback implements SensorDataFileReceiver.OnFileReceiveListener{
+
+    private static final String TAG = "SensorDataCallback";
+
+    private Context mContext;
+    private SensorDataFileReceiver mFileReceiver;
+    private ChannelClient.Channel mOpenChannel;
+
+    public SensorDataCallback(Context context) {
+        mContext = context;
+        mOpenChannel = null;
+
+        mFileReceiver = new SensorDataFileReceiver(mContext);
+        mFileReceiver.add(this);
+    }
+
+    @Override
+    public void onChannelOpened(@NonNull ChannelClient.Channel openChannel) {
+        super.onChannelOpened(openChannel);
+
+        mOpenChannel = openChannel;
+        Wearable.getChannelClient(mContext).getInputStream(mOpenChannel).addOnSuccessListener((InputStream stream) -> {
+
+            mFileReceiver.setOpenStream(stream);
+            new Thread(mFileReceiver, "FileReceiverThread").start();
+        });
+    }
+
+    @Override
+    public void onChannelClosed(@NonNull ChannelClient.Channel openChannel, int closeReason, int appSpecificErrorCode) {
+        super.onChannelClosed(openChannel, closeReason, appSpecificErrorCode);
+
+        Log.d(TAG, "Channel is closed. Reason: " + closeReason + " - ErrorCode: " + appSpecificErrorCode);
+    }
+
+    @Override
+    public void onStartSaveFile() {
+        //TODO: runOnUIThread stuff
+
+        Log.d(TAG, "Start saving file. - " + Thread.currentThread().getName());
+    }
+
+    @Override
+    public void onFinishedSavingFile() {
+
+        //close the channel
+        if(mOpenChannel != null){
+            Wearable.getChannelClient(mContext).close(mOpenChannel);
+        }
+
+        Log.d(TAG, "Finished saving file. - " + Thread.currentThread().getName());
+    }
+}
diff --git a/android/ConductorsPhone/app/src/main/java/de/tonifetzer/conductorswatch/network/SensorDataFileReceiver.java b/android/ConductorsPhone/app/src/main/java/de/tonifetzer/conductorswatch/network/SensorDataFileReceiver.java
new file mode 100644
index 0000000..db9526c
--- /dev/null
+++ b/android/ConductorsPhone/app/src/main/java/de/tonifetzer/conductorswatch/network/SensorDataFileReceiver.java
@@ -0,0 +1,111 @@
+package de.tonifetzer.conductorswatch.network;
+
+import android.content.Context;
+import android.util.Log;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.ByteBuffer;
+import java.util.List;
+import java.util.concurrent.CopyOnWriteArrayList;
+
+/**
+ * Created by toni on 14/01/18.
+ */
+
+public class SensorDataFileReceiver implements Runnable {
+
+    private InputStream mOpenStream;
+    private Context mContext;
+    private static final String TAG = "SensorDataFileReceiver";
+
+    public SensorDataFileReceiver(Context context){
+        mOpenStream = null;
+        mContext = context;
+    }
+
+    public void setOpenStream(InputStream stream){
+        mOpenStream = stream;
+    }
+
+    @Override
+    public void run() {
+
+        if(mOpenStream != null){
+
+            Log.d(TAG, "Opened InputStream in Thread: " + Thread.currentThread().getName());
+
+            for(SensorDataFileReceiver.OnFileReceiveListener listener : listeners){
+                listener.onStartSaveFile();
+            }
+
+            byte[] bytesTimestamp = new byte[Long.BYTES];
+            byte[] bytesSensorID = new byte[Integer.BYTES];
+            byte[] bytesX= new byte[Double.BYTES];
+            byte[] bytesY= new byte[Double.BYTES];
+            byte[] bytesZ= new byte[Double.BYTES];
+
+            long ts = 0;
+            int id = 0;
+            double x = 0, y = 0, z = 0;
+
+            int i = 0;
+            SensorDataFileWriter fileWriter = new SensorDataFileWriter(mContext);
+
+            try {
+                while(mOpenStream.read(bytesTimestamp) != -1) {
+                    ts = ByteBuffer.wrap(bytesTimestamp).getLong();
+
+                    mOpenStream.read(bytesSensorID);
+                    id = ByteBuffer.wrap(bytesSensorID).getInt();
+
+                    mOpenStream.read(bytesX);
+                    x = ByteBuffer.wrap(bytesX).getDouble();
+
+                    mOpenStream.read(bytesY);
+                    y = ByteBuffer.wrap(bytesY).getDouble();
+
+                    mOpenStream.read(bytesZ);
+                    z = ByteBuffer.wrap(bytesZ).getDouble();
+
+                    ++i;
+
+                    if(id != 4 && id != 10){
+                        Log.d(TAG, "STOOOOOP");
+                    }
+
+                    fileWriter.writeVector3D(ts, id, x, y, z);
+                }
+
+                //we have what we wanted, so close the channel
+                fileWriter.toDisk();
+                Log.d(TAG, "Num Data transferred: " + i);
+
+                //finished callback
+                for(SensorDataFileReceiver.OnFileReceiveListener listener : listeners){
+                    listener.onFinishedSavingFile();
+                }
+
+                //close the stream, since this is recommended
+                mOpenStream.close();
+
+            } catch (IOException e) {
+                e.printStackTrace();
+            }
+        } else {
+            Log.d(TAG, "Channel is not valid, is it really open? Check connection to watch! - Thread: " + Thread.currentThread().getName());
+        }
+    }
+
+
+    /**
+     * Interface for callback
+     */
+    public interface OnFileReceiveListener {
+        void onStartSaveFile();
+        void onFinishedSavingFile();
+    }
+
+    private List<OnFileReceiveListener> listeners = new CopyOnWriteArrayList<OnFileReceiveListener>();
+    public void add(SensorDataFileReceiver.OnFileReceiveListener listener){listeners.add(listener);}
+    public void remove(SensorDataFileReceiver.OnFileReceiveListener listener){listeners.remove(listener);}
+}
diff --git a/android/ConductorsPhone/app/src/main/java/de/tonifetzer/conductorswatch/network/SensorDataFileWriter.java b/android/ConductorsPhone/app/src/main/java/de/tonifetzer/conductorswatch/network/SensorDataFileWriter.java
new file mode 100644
index 0000000..6780856
--- /dev/null
+++ b/android/ConductorsPhone/app/src/main/java/de/tonifetzer/conductorswatch/network/SensorDataFileWriter.java
@@ -0,0 +1,139 @@
+package de.tonifetzer.conductorswatch.network;
+
+import android.app.Activity;
+import android.content.Context;
+import android.os.AsyncTask;
+import android.util.Log;
+import android.widget.EditText;
+import android.widget.TextView;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+
+import de.tonifetzer.conductorswatch.DataFolder;
+import de.tonifetzer.conductorswatch.R;
+
+/**
+ * Created by toni on 14/01/18.
+ */
+
+public class SensorDataFileWriter {
+
+    private static final int FLUSH_LIMIT = 2*1024*1024;
+    private static final String TAG = "SensorDataFileWriter";
+
+    private File mSensorDataFile;
+    private FileOutputStream mFileOutputStream;
+    private StringBuilder mStringBuilder = new StringBuilder();
+    private final DataFolder mFolder;
+    private boolean mStreamOpenend = false;
+
+    public SensorDataFileWriter(Context context) {
+
+        mFolder = new DataFolder(context, "sensorOutFiles");
+
+        //write some description for this file in the first line
+        EditText editView = ((Activity) context).findViewById(R.id.comments);
+        TextView textView = ((Activity) context).findViewById(R.id.bpmText);
+        writeDescription("Kommentar: " + editView.getText().toString() + "\nMetronom: " +  textView.getText().toString() + " bpm");
+
+        //open connection to file
+        open();
+    }
+
+    public final void writeVector3D(long ts, int id, double x, double y, double z){
+
+        synchronized (this) {
+
+            if (mStreamOpenend) {
+
+                mStringBuilder.append(ts).append(';').append(id).append(';').append(x).append(';').append(y).append(';').append(z).append('\n');
+
+                if (mStringBuilder.length() > FLUSH_LIMIT) {flush(false);}
+            } else {
+                open();
+            }
+        }
+    }
+
+    private final void writeDescription(String str){
+        synchronized (this) {
+            mStringBuilder.append(str).append('\n').append('\n');
+        }
+
+    }
+
+    // flush data to disk
+    public final void toDisk(){
+        synchronized (this) {
+            flush(true);
+            close();
+        }
+    }
+
+    /** helper method for exception-less writing. DO NOT CALL DIRECTLY! */
+    private final void _write(final byte[] data) {
+        try {
+            mFileOutputStream.write(data);
+            Log.d(TAG, "flushed " + data.length + " bytes to disk");
+        } catch (final Exception e) {
+            throw new RuntimeException("error while writing log-file", e);
+        }
+    }
+
+    /** helper-class for background writing */
+    class FlushAsync extends AsyncTask<byte[], Integer, Integer> {
+        @Override
+        protected final Integer doInBackground(byte[][] data) {
+            _write(data[0]);
+            return null;
+        }
+    };
+
+    /** flush current buffer-contents to disk */
+    private final void flush(boolean sync) {
+
+        // fetch current buffer contents to write and hereafter empty the buffer
+        // this action MUST be atomic, just like the add-method
+        byte[] data = null;
+        synchronized (this) {
+            data = mStringBuilder.toString().getBytes();		// fetch data to write
+            mStringBuilder.setLength(0);						// reset the buffer
+        }
+
+        // write
+        if (sync) {
+            // write to disk using the current thread
+            _write(data);
+        } else {
+            // write to disk using a background-thread
+            new FlushAsync().execute(new byte[][] {data});
+        }
+    }
+
+    private final void open() {
+        mSensorDataFile = new File(mFolder.getFolder(), System.currentTimeMillis() + ".csv");
+
+        try {
+            mFileOutputStream = new FileOutputStream(mSensorDataFile);
+            mStreamOpenend = true;
+
+            Log.d(TAG, "will write to: " + mSensorDataFile.toString());
+        } catch (FileNotFoundException e) {
+            e.printStackTrace();
+
+            mStreamOpenend = false;
+        }
+    }
+
+    private final void close() {
+        try {
+            mFileOutputStream.close();
+            mStreamOpenend = false;
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+}
diff --git a/android/ConductorsPhone/app/src/main/res/layout/activity_main.xml b/android/ConductorsPhone/app/src/main/res/layout/activity_main.xml
index 3c2d36b..c454833 100644
--- a/android/ConductorsPhone/app/src/main/res/layout/activity_main.xml
+++ b/android/ConductorsPhone/app/src/main/res/layout/activity_main.xml
@@ -1,23 +1,38 @@
 <?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"
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    tools:context="de.tonifetzer.conductorswatch.MainActivity">
+    android:orientation="vertical"
+    tools:context="de.tonifetzer.conductorswatch.MainActivity"
+    android:gravity="center">
 
     <TextView
         android:id="@+id/bpmText"
-        android:soundEffectsEnabled="true"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        app:layout_constraintBottom_toBottomOf="parent"
-        app:layout_constraintLeft_toLeftOf="parent"
-        app:layout_constraintRight_toRightOf="parent"
-        app:layout_constraintTop_toTopOf="parent"
+        android:soundEffectsEnabled="true"
         android:text="80"
-        android:textStyle="bold"
         android:textColor="#158b69"
-        android:textSize="100sp"/>
+        android:textSize="100sp"
+        android:textStyle="bold"
+        android:layout_centerHorizontal="true"/>
 
-</android.support.constraint.ConstraintLayout>
+    <TextView
+        android:id="@+id/Text"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:soundEffectsEnabled="true"
+        android:text="Kommentare zur Aufnahme:"
+        android:textStyle="bold" />
+
+    <EditText
+        android:id="@+id/comments"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:ems="10"
+        android:inputType="textMultiLine"
+        android:text=""
+        android:layout_centerHorizontal="true"/>
+
+</LinearLayout>
diff --git a/android/ConductorsPhone/app/src/main/res/raw/metronom.flac b/android/ConductorsPhone/app/src/main/res/raw/metronom.flac
new file mode 100644
index 0000000..fb19be0
Binary files /dev/null and b/android/ConductorsPhone/app/src/main/res/raw/metronom.flac differ
diff --git a/android/ConductorsPhone/app/src/main/res/raw/metronom2.wav b/android/ConductorsPhone/app/src/main/res/raw/metronom2.wav
new file mode 100644
index 0000000..9e1c88a
Binary files /dev/null and b/android/ConductorsPhone/app/src/main/res/raw/metronom2.wav differ
diff --git a/android/ConductorsPhone/app/src/main/res/raw/metronom3.wav b/android/ConductorsPhone/app/src/main/res/raw/metronom3.wav
new file mode 100644
index 0000000..ff84b9c
Binary files /dev/null and b/android/ConductorsPhone/app/src/main/res/raw/metronom3.wav differ
diff --git a/android/ConductorsPhone/app/src/main/res/values/styles.xml b/android/ConductorsPhone/app/src/main/res/values/styles.xml
index 5885930..0eb88fe 100644
--- a/android/ConductorsPhone/app/src/main/res/values/styles.xml
+++ b/android/ConductorsPhone/app/src/main/res/values/styles.xml
@@ -1,7 +1,7 @@
 <resources>
 
     <!-- Base application theme. -->
-    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
+    <style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
         <!-- Customize your theme here. -->
         <item name="colorPrimary">@color/colorPrimary</item>
         <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
diff --git a/android/ConductorsWatch/app/build.gradle b/android/ConductorsWatch/app/build.gradle
index 3379d81..129c2f4 100644
--- a/android/ConductorsWatch/app/build.gradle
+++ b/android/ConductorsWatch/app/build.gradle
@@ -8,8 +8,9 @@ android {
         applicationId "de.tonifetzer.conductorswatch"
         minSdkVersion 23
         targetSdkVersion 26
-        versionCode 1
-        versionName "1.0"
+        //sdk 2 | product version 3 | build num 2 | multi-apk 2
+        versionCode 260120101
+        versionName "0.1.2"
     }
     buildTypes {
         release {
diff --git a/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/Croller.java b/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/Croller.java
index 18d90e3..e3b7db3 100644
--- a/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/Croller.java
+++ b/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/Croller.java
@@ -231,6 +231,7 @@ public class Croller extends View {
     protected void onDraw(Canvas canvas) {
         super.onDraw(canvas);
 
+        //called way to much!
         if (mProgressChangeListener != null)
             mProgressChangeListener.onProgressChanged((int) (deg - 2));
 
@@ -502,8 +503,10 @@ public class Croller extends View {
     }
 
     public void setProgress(int x) {
-        deg = x + 2;
-        invalidate();
+        if(deg != x + 2){
+            deg = x + 2;
+            invalidate();
+        }
     }
 
     public String getLabel() {
@@ -511,8 +514,10 @@ public class Croller extends View {
     }
 
     public void setLabel(String txt) {
-        label = txt;
-        invalidate();
+        if(!label.equals(txt)){
+            label = txt;
+            invalidate();
+        }
     }
 
     public int getBackCircleColor() {
@@ -520,8 +525,10 @@ public class Croller extends View {
     }
 
     public void setBackCircleColor(int backCircleColor) {
-        this.backCircleColor = backCircleColor;
-        invalidate();
+        if(this.backCircleColor != backCircleColor){
+            this.backCircleColor = backCircleColor;
+            invalidate();
+        }
     }
 
     public int getMainCircleColor() {
@@ -529,8 +536,10 @@ public class Croller extends View {
     }
 
     public void setMainCircleColor(int mainCircleColor) {
-        this.mainCircleColor = mainCircleColor;
-        invalidate();
+        if(this.mainCircleColor != mainCircleColor){
+            this.mainCircleColor = mainCircleColor;
+            invalidate();
+        }
     }
 
     private ValueAnimator mainCircleAnimation;
diff --git a/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/Estimator.java b/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/Estimator.java
index e65ae2f..5bb93f0 100644
--- a/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/Estimator.java
+++ b/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/Estimator.java
@@ -6,50 +6,40 @@ import android.hardware.SensorEvent;
 import android.hardware.SensorEventListener;
 import android.hardware.SensorManager;
 import android.os.Handler;
+
 import java.util.List;
+import java.util.Timer;
+import java.util.TimerTask;
 import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
 
 import de.tonifetzer.conductorswatch.bpmEstimation.AccelerometerData;
 import de.tonifetzer.conductorswatch.bpmEstimation.AccelerometerWindowBuffer;
 import de.tonifetzer.conductorswatch.bpmEstimation.BpmEstimator;
-import de.tonifetzer.conductorswatch.utilities.Utils;
+import de.tonifetzer.conductorswatch.network.SensorDataFileSender;
+import de.tonifetzer.conductorswatch.network.SensorDataFileStreamer;
+import de.tonifetzer.conductorswatch.utilities.ByteStreamWriter;
 
 /**
  * Created by toni on 13/11/17.
  */
 
-//TODO: einfügen der logik autoCorr + FindPeaks
 public class Estimator implements SensorEventListener {
 
     private SensorManager mSensorManager;
     private Sensor mAccelerometer;
+    private Sensor mGyroscope;
     private Context mContext;
     private AccelerometerWindowBuffer mAccelerometerWindowBuffer;
     private BpmEstimator mBpmEstimator;
 
-    private Handler mHandler;
-    private int mUpdaterate_ms = 100;
-    private boolean mSensorUpdateFlag = false;
+    private ByteStreamWriter mByteStreamWriterAcc;
+    private ByteStreamWriter mByteStreamWriterGyro;
+    private SensorDataFileStreamer mStreamer;
 
-
-    private final Runnable mProcessSensors = new Runnable() {
-        @Override
-        public void run() {
-
-            if(mAccelerometerWindowBuffer.isNextWindowReady()){
-
-                double bpm = mBpmEstimator.estimate();
-
-                for (OnBpmEstimatorListener listener:listeners) {
-                    listener.onNewDataAvailable(bpm);
-                }
-            }
-
-            mSensorUpdateFlag = true;
-            // The Runnable is posted to run again here:
-            mHandler.postDelayed(this, mUpdaterate_ms);
-        }
-    };
+    private Timer mTimer = new Timer();
 
 
     public Estimator(Context mContext){
@@ -60,36 +50,73 @@ public class Estimator implements SensorEventListener {
 
         mSensorManager = (SensorManager) mContext.getSystemService(Context.SENSOR_SERVICE);
         mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_LINEAR_ACCELERATION);
+        mGyroscope = mSensorManager.getDefaultSensor(Sensor.TYPE_GYROSCOPE);
         mSensorManager.registerListener(this, mAccelerometer, SensorManager.SENSOR_DELAY_FASTEST);
+        mSensorManager.registerListener(this, mGyroscope, SensorManager.SENSOR_DELAY_FASTEST);
 
         mAccelerometerWindowBuffer = new AccelerometerWindowBuffer(1024, 256);
         mBpmEstimator = new BpmEstimator(mAccelerometerWindowBuffer, 0, 5000);
 
-        mHandler = new Handler();
-        mHandler.post(mProcessSensors); //start runnable
+        mTimer.scheduleAtFixedRate(new TimerTask() {
+            @Override
+            public void run() {
+
+                if (mAccelerometerWindowBuffer.isNextWindowReady()) {
+                    double bpm = mBpmEstimator.estimate(mAccelerometerWindowBuffer.getFixedWindow());
+
+                    for (OnBpmEstimatorListener listener : listeners) {
+                        listener.onNewDataAvailable(bpm);
+                    }
+                }
+            }
+        }, 0, 100);
+
+        mByteStreamWriterAcc = new ByteStreamWriter();
+        mByteStreamWriterGyro = new ByteStreamWriter();
+
+        mStreamer = new SensorDataFileStreamer(mContext);
+        new Thread(mStreamer).start();
     }
 
 
     public void stop() {
-        mHandler.removeCallbacks(mProcessSensors); //remove runnable
+
+        mTimer.cancel();
+        mTimer.purge();
+
         mSensorManager.unregisterListener(this);
+
+        //send data and close the ByteStreamWriter
+        for (OnBpmEstimatorListener listener : listeners) {
+            //listener.onEstimationStopped(mByteStreamWriter.getByteArray());
+        }
+        mByteStreamWriterAcc.close();
+        mByteStreamWriterGyro.close();
+
+        mStreamer.close();
     }
 
     @Override
     public void onSensorChanged(SensorEvent se) {
 
-        // einkommentieren, falls die updaterate beschränkt werden soll. aktuell maximum speed
-        //if(mSensorUpdateFlag) {
+        //TODO: at the moment this runs in main thread... since worker fragment runs also in main thread
 
         //ca 200hz, every 5 to 6 ms we have an update
             if (se.sensor.getType() == Sensor.TYPE_LINEAR_ACCELERATION) {
                 mAccelerometerWindowBuffer.add(new AccelerometerData(System.currentTimeMillis(), se.values[0], se.values[1], se.values[2]));
+                mByteStreamWriterAcc.writeSensor3D(Sensor.TYPE_LINEAR_ACCELERATION, se.values[0], se.values[1], se.values[2]);
+
+                mStreamer.sendByteArray(mByteStreamWriterAcc.getByteArray());
+                mByteStreamWriterAcc.reset();
             }
 
-            //TODO: get also gyro and write stuff into file
+            if (se.sensor.getType() == Sensor.TYPE_GYROSCOPE) {
+                //TODO: Rename AccelerometerData to SensorData3D
+                mByteStreamWriterGyro.writeSensor3D(Sensor.TYPE_GYROSCOPE,  se.values[0], se.values[1], se.values[2]);
 
-           // mSensorUpdateFlag = false;
-        //}
+                mStreamer.sendByteArray(mByteStreamWriterGyro.getByteArray());
+                mByteStreamWriterGyro.reset();
+            }
     }
 
     @Override
@@ -97,12 +124,12 @@ public class Estimator implements SensorEventListener {
         // do nothin
     }
 
-
     /**
      * Interface for callback calculated bpm
      */
     public interface OnBpmEstimatorListener {
         void onNewDataAvailable(double bpm);
+        void onEstimationStopped(byte[] sensorData);
     }
 
     private List<OnBpmEstimatorListener> listeners = new CopyOnWriteArrayList<OnBpmEstimatorListener>();
diff --git a/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/MainActivity.java b/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/MainActivity.java
index 58fc630..f5ce3a7 100644
--- a/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/MainActivity.java
+++ b/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/MainActivity.java
@@ -7,48 +7,29 @@ import android.graphics.Point;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.Vibrator;
-import android.support.annotation.NonNull;
-import android.support.annotation.Nullable;
 import android.support.wearable.activity.WearableActivity;
 import android.util.Log;
 import android.view.GestureDetector;
 import android.view.MotionEvent;
 import android.widget.TextView;
 
-import com.google.android.gms.common.ConnectionResult;
-import com.google.android.gms.common.api.GoogleApiClient;
-import com.google.android.gms.common.api.ResultCallback;
-import com.google.android.gms.wearable.MessageApi;
-import com.google.android.gms.wearable.Node;
-import com.google.android.gms.wearable.NodeApi;
-import com.google.android.gms.wearable.Wearable;
-
-import java.sql.Time;
-import java.util.List;
-import java.util.Vector;
-import java.util.concurrent.TimeUnit;
-
+import de.tonifetzer.conductorswatch.network.SensorDataFileSender;
 import de.tonifetzer.conductorswatch.utilities.Utils;
 
-public class MainActivity extends WearableActivity implements WorkerFragment.OnFragmentInteractionListener, TapBpm.OnTapBpmListener, GoogleApiClient.ConnectionCallbacks,
-        GoogleApiClient.OnConnectionFailedListener{
+public class MainActivity extends WearableActivity implements WorkerFragment.OnFragmentInteractionListener, TapBpm.OnTapBpmListener {
 
     // member
     private TextView mTextView;
     private Croller mCroller;
     private GestureDetector mDetector;
-    private boolean mModeRecord;
+    private boolean mModeRecord = false;
 
     // connection to phone stuff
-    private static final String START_ACTIVITY_PATH = "/start-activity";
     private static final String START_RECORD_PATH = "/start-record";
     private static final String STOP_RECORD_PATH = "/stop-record";
     private static final String UPDATE_PATH = "/update";
-
-    public static final String TAG = "DataLayerListenerService";
-    private GoogleApiClient mGoogleApiClient;
-    private Node mNode;
-    private boolean mResolvingError = false;
+    private SensorDataFileSender mSender;
+    private volatile boolean mReadyToSend = true;
 
     // display center
     private int mDisplayWidth;
@@ -56,7 +37,8 @@ public class MainActivity extends WearableActivity implements WorkerFragment.OnF
     private Point mDisplayCenter;
 
     // saved Bpm to reset after recording
-    private int mMetronomBpm;
+    private int mMetronomBpm = 80;
+    private int mLastSendBPM = 80;
 
     // tapping
     private Thread mTapBpmThread;
@@ -81,7 +63,7 @@ public class MainActivity extends WearableActivity implements WorkerFragment.OnF
 
             mModeRecord = !mModeRecord;
 
-            if(mModeRecord){
+            if (mModeRecord) {
                 WorkerFragment worker = new WorkerFragment();
 
                 //provide the fragment with the bpm set
@@ -90,71 +72,71 @@ public class MainActivity extends WearableActivity implements WorkerFragment.OnF
                 worker.setArguments(args);
 
                 //send data to phone, that we start to record
-                String curProgress = Integer.toString(mCroller.getProgress());
-                sendMessage(START_RECORD_PATH + ":" + curProgress + ":" + curProgress);
+                mMetronomBpm = mCroller.getProgress();
+                mSender.sendMessage(START_RECORD_PATH + ":" + mMetronomBpm + ":" + mMetronomBpm);
 
                 //setter
                 worker.setCrollerWorker(mCroller);
                 worker.setTextViewWorker(mTextView);
-                mMetronomBpm = mCroller.getProgress();
 
                 //create fragment instance
                 FragmentTransaction transaction = getFragmentManager().beginTransaction();
                 transaction.replace(R.id.layout, worker, "Worker");
                 transaction.addToBackStack("Worker");
                 transaction.commit();
-            }
-            else {
-                getFragmentManager().popBackStack();
-                mCroller.interruptMainCircleColorAnimated();
+            } else {
+
                 mCroller.setProgressPrimaryColor(Color.parseColor("#158b69"));
                 mCroller.setBackCircleColor(Color.parseColor("#158b69"));
                 mTextView.setTextColor(Color.parseColor("#158b69"));
+                mCroller.interruptMainCircleColorAnimated();
                 mCroller.setProgress(mMetronomBpm);
 
                 //send data to phone, that we stopped to record
-                sendMessage(STOP_RECORD_PATH);
+                mSender.sendMessage(STOP_RECORD_PATH);
+
+                getFragmentManager().popBackStack();
             }
         }
     };
 
-    private boolean onLongPressCustomized(MotionEvent ev){
+    private boolean onLongPressCustomized(MotionEvent ev) {
 
-        Point currentPoint = new Point((int)ev.getX(), (int)ev.getY());
+        Point currentPoint = new Point((int) ev.getX(), (int) ev.getY());
 
         //make sure the longPress only works within the maincircle of the scroller
-        double distancePointToMiddle = Utils.getDistance(currentPoint.x, currentPoint.y, (mDisplayWidth / 2.0f), (mDisplayHeight / 2.0f));
-        if ((distancePointToMiddle > mCroller.getMainCircleRadius())){
+        double distancePointToMiddle = Utils.getDistance(currentPoint.x, currentPoint.y, mDisplayCenter.x, mDisplayCenter.y);
+        if ((distancePointToMiddle > mCroller.getBackCircleRadius())) {
             mHandler.removeCallbacks(mLongPressed);
             return false;
         }
 
-        if(ev.getAction() == MotionEvent.ACTION_DOWN){
+        if (ev.getAction() == MotionEvent.ACTION_DOWN) {
             mHandler.postDelayed(mLongPressed, mLongPressDelay);
         }
 
-        if((ev.getAction() == MotionEvent.ACTION_MOVE) || (ev.getAction() == MotionEvent.ACTION_HOVER_MOVE)){
+        if ((ev.getAction() == MotionEvent.ACTION_MOVE) || (ev.getAction() == MotionEvent.ACTION_HOVER_MOVE)) {
 
-            if(mPreviousMovePoint == null) {
+            /*
+            if (mPreviousMovePoint == null) {
                 mPreviousMovePoint = currentPoint;
-            }
-            else {
+            } else {
                 int dx = Math.abs(currentPoint.x - mPreviousMovePoint.x);
                 int dy = Math.abs(currentPoint.y - mPreviousMovePoint.y);
-                int distance = (int) Math.sqrt(dx*dx + dy*dy);
-                if(distance > mDistanceJitteringLongPress) {
+                int distance = (int) Math.sqrt(dx * dx + dy * dy);
+                if (distance > mDistanceJitteringLongPress) {
                     mHandler.removeCallbacks(mLongPressed);
                     return false;
                 }
-            }
+            }*/
         }
 
-        if(ev.getAction() == MotionEvent.ACTION_UP){
+        if (ev.getAction() == MotionEvent.ACTION_UP) {
             mHandler.removeCallbacks(mLongPressed);
-            if(mLongPressHandlerActivated){
+            if (mLongPressHandlerActivated) {
                 mLongPressHandlerActivated = false;
                 mPreviousMovePoint = null;
-                return true;
+                return false;
             }
             return false;
         }
@@ -162,37 +144,35 @@ public class MainActivity extends WearableActivity implements WorkerFragment.OnF
         return false;
     }
 
-    private boolean onColorChanging(MotionEvent ev, int MainColor){
-        Point currentPoint = new Point((int)ev.getX(), (int)ev.getY());
+    private boolean onColorChanging(MotionEvent ev, int MainColor) {
+        Point currentPoint = new Point((int) ev.getX(), (int) ev.getY());
 
         //only works within the maincircle of the scroller
         double distancePointToMiddle = Utils.getDistance(currentPoint.x, currentPoint.y, mDisplayCenter.x, mDisplayCenter.y);
-        if ((distancePointToMiddle > mCroller.getMainCircleRadius())){
+        if ((distancePointToMiddle > mCroller.getBackCircleRadius())) {
 
             //if we are outside the area of interest and the animation is already running, we need to reset
-            if(mCroller.isMainCircleAnimationRunning() || mCroller.isBackCircleAnimationRunning()){
+            if (mCroller.isMainCircleAnimationRunning() || mCroller.isBackCircleAnimationRunning()) {
                 mCroller.interruptMainCircleColorAnimated();
                 mCroller.interruptBackCircleAnimated();
             }
-            else {
                 mCroller.setBackCircleColor(Color.parseColor("#cccccc"));
                 mCroller.setMainCircleColor(Color.parseColor("#ffffff"));
-            }
 
             return false;
         }
 
-        if(ev.getAction() == MotionEvent.ACTION_DOWN){
+        if (ev.getAction() == MotionEvent.ACTION_DOWN) {
             //push down effect back circle (ring around main circle)
-            mCroller.setBackCircleColorAnimated(Color.parseColor("#cccccc"), MainColor,150);
+            mCroller.setBackCircleColorAnimated(Color.parseColor("#cccccc"), MainColor, 150);
 
             //make color of main circle brighter the longer we press
-            mCroller.setMainCircleColorAnimated(Color.parseColor("#ffffff"), MainColor,1500);
+            mCroller.setMainCircleColorAnimated(Color.parseColor("#ffffff"), MainColor, 1300);
         }
 
-        if(ev.getAction() == MotionEvent.ACTION_UP){
+        if (ev.getAction() == MotionEvent.ACTION_UP) {
             //push_up effect back circle (ring around main circle)
-            mCroller.setBackCircleColorAnimated(MainColor, Color.parseColor("#cccccc"),150);
+            mCroller.setBackCircleColorAnimated(MainColor, Color.parseColor("#cccccc"), 150);
 
             // if we remove our finger before longpress was recognized, reverse animation
             mCroller.stopMainCircleColorAnimated();
@@ -201,30 +181,30 @@ public class MainActivity extends WearableActivity implements WorkerFragment.OnF
         return false;
     }
 
-    public boolean onTapForBpm(MotionEvent ev){
+    public boolean onTapForBpm(MotionEvent ev) {
 
-        Point currentPoint = new Point((int)ev.getX(), (int)ev.getY());
+        Point currentPoint = new Point((int) ev.getX(), (int) ev.getY());
 
         //only works within the maincircle of the scroller
         double distancePointToMiddle = Utils.getDistance(currentPoint.x, currentPoint.y, mDisplayCenter.x, mDisplayCenter.y);
-        if ((distancePointToMiddle > mCroller.getMainCircleRadius())){
+        if ((distancePointToMiddle > mCroller.getBackCircleRadius())) {
 
             mCroller.setProgress(mCroller.getProgress());
             return false;
         }
 
-        if(ev.getAction() == MotionEvent.ACTION_DOWN){
+        if (ev.getAction() == MotionEvent.ACTION_DOWN) {
 
-            if(!mTapRecognized){
+            if (!mTapRecognized) {
 
                 mTapBpm.addTimestamp(System.currentTimeMillis());
                 mTapRecognized = true;
             }
         }
 
-        if(ev.getAction() == MotionEvent.ACTION_UP) {
+        if (ev.getAction() == MotionEvent.ACTION_UP) {
 
-            if(!mTapBpmThread.isAlive() && mTapRecognized){
+            if (!mTapBpmThread.isAlive() && mTapRecognized) {
                 mTapBpmThread.start();
                 mCroller.setLabel("Tippe weiter");
             }
@@ -240,20 +220,11 @@ public class MainActivity extends WearableActivity implements WorkerFragment.OnF
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
 
-        //init GoogleApiClient and get nodeid (phone)
-        mGoogleApiClient = new GoogleApiClient.Builder(this)
-                .addApi(Wearable.API)
-                .addConnectionCallbacks(this)
-                .addOnConnectionFailedListener(this)
-                .build();
-
         //get display infos
-        mDisplayWidth= this.getResources().getDisplayMetrics().widthPixels;
-        mDisplayHeight= this.getResources().getDisplayMetrics().heightPixels;
+        mDisplayWidth = this.getResources().getDisplayMetrics().widthPixels;
+        mDisplayHeight = this.getResources().getDisplayMetrics().heightPixels;
         mDisplayCenter = new Point((mDisplayWidth / 2), (mDisplayHeight / 2));
 
-        mModeRecord = false;
-
         mTapBpm = new TapBpm();
         mTapBpm.add(this);
         mTapBpmThread = new Thread(mTapBpm, "tapThread");
@@ -261,24 +232,33 @@ public class MainActivity extends WearableActivity implements WorkerFragment.OnF
 
         mTextView = (TextView) findViewById(R.id.bpmText);
 
+        mSender = new SensorDataFileSender(this);
+
         // circular progress bar
         mCroller = (Croller) findViewById(R.id.croller);
         mCroller.setOnProgressChangedListener(new Croller.onProgressChangedListener() {
             @Override
-            public void onProgressChanged(int progress) {
-                // use the progress
-                String curProgress = Integer.toString(progress);
-                String metronomBpm = Integer.toString(mMetronomBpm);;
-                mTextView.setText(curProgress);
+            public void onProgressChanged(int currentBPM) {
 
-                //TODO: too many messages? or just because of thread?
-                if(mModeRecord){
-                    sendMessage(START_RECORD_PATH + ":" + metronomBpm + ":" +  curProgress);
-                }
-                else {
-                    sendMessage(UPDATE_PATH + ":" + metronomBpm + ":" +  curProgress);
+                if(currentBPM != mLastSendBPM){
+
+                    mTextView.setText(Integer.toString(currentBPM));
+                    mSender.sendMessage(UPDATE_PATH + ":" + mMetronomBpm + ":" + currentBPM);
+                    mLastSendBPM = currentBPM;
                 }
 
+                if(mReadyToSend){
+                    mReadyToSend = false;
+                    new java.util.Timer().schedule(
+                            new java.util.TimerTask() {
+                                @Override
+                                public void run() {
+                                    // your code here
+
+                                    mReadyToSend = true;
+                                }
+                            }, 100);
+                }
             }
         });
 
@@ -297,82 +277,67 @@ public class MainActivity extends WearableActivity implements WorkerFragment.OnF
         setAmbientEnabled();
     }
 
-    private void sendMessage(String Key) {
-
-        //TODO: sammel key's und schicke nur die hälfte
-
-        if (mNode != null && mGoogleApiClient!= null && mGoogleApiClient.isConnected()) {
-            //Log.d(TAG, "-- " + mGoogleApiClient.isConnected());
-            Wearable.MessageApi.sendMessage(
-                    mGoogleApiClient, mNode.getId(), Key, new byte[0]).setResultCallback(
-
-                    new ResultCallback<MessageApi.SendMessageResult>() {
-                        @Override
-                        public void onResult(MessageApi.SendMessageResult sendMessageResult) {
-
-                            //Log.d(TAG, "-- " + sendMessageResult.getStatus().getStatusCode());
-                            if (!sendMessageResult.getStatus().isSuccess()) {
-                                Log.e(TAG, "Failed to send message with status code: "
-                                        + sendMessageResult.getStatus().getStatusCode());
-                            }
-                        }
-                    }
-            );
-        }
-
-    }
-
     @Override
     public boolean dispatchTouchEvent(MotionEvent ev) {
 
         //if record mode is on, we are not able to use the croller
-        if(mModeRecord){
+        if (mModeRecord) {
 
+            //TODO: jedes mal wenn ich touche ruft eine der beiden funktionen was im croller auf und der ruft neu zeichnen auf, was den progresslistener aufruf.
+            //bei extrem vielen berührungen des displays kackt alles ab. er zeichnet auch ständig alles neu
             boolean changeColor = onColorChanging(ev, Color.parseColor("#EE693F"));
             return onLongPressCustomized(ev);
-        }
-        else {
+        } else {
 
             boolean changeColor = onColorChanging(ev, Color.parseColor("#158b69"));
             boolean superTouch = super.dispatchTouchEvent(ev);
             boolean longPress = onLongPressCustomized(ev);
             boolean tapForBpm = onTapForBpm(ev);
 
-            return  superTouch || longPress;
+            return superTouch || longPress;
         }
 
     }
 
     @Override
-    public void onFragmentStopped(Vector<Double> bpmList) {
-
-        //TODO: save the bpmList into a file
-
-        //TODO: send bpmList and all other data to phone
-
-        Log.d("FragmentListener", "Received bpmList");
+    public void onFragmentStopped() {
+        //mSender.sendByteArray(sensorData);
     }
 
     @Override
     protected void onStart() {
         super.onStart();
-        if (!mResolvingError) {
-            mGoogleApiClient.connect();
-
-            //TODO. mGoogleApiClient.disconnect(); implementieren in onPause()
-        }
     }
 
-    //TODO: rename this! onTapBPMNewEstimation or something like that
     @Override
-    public void onNewEstimation(int bpm) {
+    protected  void onResume() {
+        super.onResume();
+
+        mSender.wakeUpPhoneCall();
+        //mSender.register();
+    }
+
+    @Override
+    protected void onPause() {
+        super.onPause();
+
+        //mSender.unregister();
+    }
+
+    @Override
+    protected  void onStop() {
+        super.onStop();
+    }
+
+    @Override
+    public void onNewTapEstimation(int bpm) {
         mTapBpmEstimation = bpm;
 
         synchronized (this) {
             runOnUiThread(new Runnable() {
                 @Override
                 public void run() {
-                    if(mTapBpmEstimation > 0){
+                    if (mTapBpmEstimation > 0) {
                         mCroller.setProgress(mTapBpmEstimation);
                         mCroller.setLabel("Fertig");
                         mVibrator.vibrate(10);
@@ -382,9 +347,8 @@ public class MainActivity extends WearableActivity implements WorkerFragment.OnF
         }
     }
 
-    //TODO: rename this! onTapBPMFinished or something like that
     @Override
-    public void onFinished() {
+    public void onTapFinished() {
 
         runOnUiThread(new Runnable() {
             @Override
@@ -395,55 +359,14 @@ public class MainActivity extends WearableActivity implements WorkerFragment.OnF
 
         mTapBpm.clearTimestamps();
         mTapRecognized = false;
+        /*
         mTapBpmThread.interrupt();
         try {
             mTapBpmThread.join();
         } catch (InterruptedException e) {
             e.printStackTrace();
         }
+        */
     }
 
-    @Override
-    public void onConnected(@Nullable Bundle bundle) {
-        resolveNode();
-
-        new Thread(new Runnable() {
-            @Override
-            public void run() {
-
-                while(mNode == null){
-                    try {
-                        Thread.sleep(1000L);
-                    } catch (InterruptedException e) {
-                        e.printStackTrace();
-                    }
-                }
-                sendMessage(START_ACTIVITY_PATH);
-            }
-        }).start();
-
-    }
-
-    @Override
-    public void onConnectionSuspended(int i) {
-        //TODO: implement this
-    }
-
-    @Override
-    public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
-        //TODO: implement this
-    }
-
-    private void resolveNode() {
-
-        Wearable.NodeApi.getConnectedNodes(mGoogleApiClient)
-                .setResultCallback(new ResultCallback<NodeApi.GetConnectedNodesResult>() {
-                    @Override
-                    public void onResult(NodeApi.GetConnectedNodesResult nodes) {
-                        for (Node node : nodes.getNodes()) {
-                            mNode = node;
-                        }
-                    }
-                });
-    }
 }
diff --git a/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/Metronome.java b/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/Metronome.java
index 7ada093..55cd34b 100644
--- a/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/Metronome.java
+++ b/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/Metronome.java
@@ -9,6 +9,7 @@ import java.util.concurrent.CopyOnWriteArrayList;
  * Created by toni on 13/11/17.
  */
 
+//TODO: implement the metronome similar to phone. since thread sleeping is no accurate enough
 public class Metronome implements Runnable{
 
     private volatile boolean mRunning = true;
@@ -27,7 +28,12 @@ public class Metronome implements Runnable{
             }
 
             try {
-                Thread.sleep(60000 / mBPM);
+                if(mBPM > 0){
+                    Thread.sleep(60000 / mBPM);
+                } else {
+                    Thread.sleep(60000);
+                }
+
             } catch (InterruptedException e) {
                 e.printStackTrace();
             }
diff --git a/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/TapBpm.java b/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/TapBpm.java
index 295119b..341b39e 100644
--- a/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/TapBpm.java
+++ b/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/TapBpm.java
@@ -35,7 +35,7 @@ public class TapBpm implements Runnable {
                 mBpmTapped = (int) (60000 / (sumDifferenceMs / (mReceivedTabs.size() - 1)));
 
                 for (TapBpm.OnTapBpmListener listener:listeners) {
-                    listener.onNewEstimation(mBpmTapped);
+                    listener.onNewTapEstimation(mBpmTapped);
                 }
 
                 //only update everytime a new timestamp arrives
@@ -45,7 +45,7 @@ public class TapBpm implements Runnable {
 
 
         for (TapBpm.OnTapBpmListener listener:listeners) {
-            listener.onFinished();
+            listener.onTapFinished();
         }
     }
 
@@ -61,8 +61,8 @@ public class TapBpm implements Runnable {
      * Interface for callback calculated bpm
      */
     public interface OnTapBpmListener {
-        void onFinished();
-        void onNewEstimation(int bpm);
+        void onTapFinished();
+        void onNewTapEstimation(int bpm);
     }
 
     private List<TapBpm.OnTapBpmListener> listeners = new CopyOnWriteArrayList<TapBpm.OnTapBpmListener>();
diff --git a/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/WorkerFragment.java b/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/WorkerFragment.java
index 2ee1082..1dc8116 100644
--- a/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/WorkerFragment.java
+++ b/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/WorkerFragment.java
@@ -22,12 +22,12 @@ import java.util.Vector;
 public class WorkerFragment extends Fragment implements Metronome.OnMetronomeListener, Estimator.OnBpmEstimatorListener{
 
     private OnFragmentInteractionListener mListener;
-    private Vector<Double> mBpmList; //TODO save to file.
+    private Vector<Double> mBpmList;
+    private byte[] mSensorData;
+    private boolean mWorkerRunning = false;
 
     private Estimator mEstimator;
     private Metronome mMetronome;
-
-    //private Thread mBpmThread;
     private Thread mMetronomeThread;
 
     private Vibrator mVibrator;
@@ -58,13 +58,12 @@ public class WorkerFragment extends Fragment implements Metronome.OnMetronomeLis
         // init bpm estimator and listener
         mEstimator = new Estimator(getContext());
         mEstimator.add(this);
-        //mBpmThread = new Thread(mEstimator, "estThread");
         mBpmList = new Vector<Double>();
 
         // init metronome and listener
         mMetronome = new Metronome(getArguments().getInt("bpm"));
         mMetronome.add(this);
-        mMetronomeThread = new Thread(mMetronome, "estThread");
+        mMetronomeThread = new Thread(mMetronome, "metronomThread");
 
         mVibrator = (Vibrator) this.getActivity().getSystemService(Context.VIBRATOR_SERVICE);
 
@@ -99,27 +98,26 @@ public class WorkerFragment extends Fragment implements Metronome.OnMetronomeLis
 
         // start the worker thread for metronom
         mMetronomeThread.start();
+
+        // everything is running
+        mWorkerRunning = true;
     }
 
     @Override
     public void onStop() {
         super.onStop();
 
+        mWorkerRunning = false;
+
         // stop the worker thread for bpm estimator
         mEstimator.stop();
 
         // stop the worker thread for metronom
         mMetronome.stop();
-        mMetronomeThread.interrupt();
-        try {
-            mMetronomeThread.join();
-        } catch (InterruptedException e) {
-            e.printStackTrace();
-        }
 
         //private listener with list of all estimated bpm
         if (mListener != null) {
-            mListener.onFragmentStopped(mBpmList);
+            mListener.onFragmentStopped();
         }
 
     }
@@ -147,33 +145,43 @@ public class WorkerFragment extends Fragment implements Metronome.OnMetronomeLis
 
         //TODO: what if multiple threads access mBpmList? put into synchronized? @frank fragen :D
         //TODO: send this to smartphone
+        if(mWorkerRunning){
+            if(bpm == -1){
+                //to stuff with UI. Write Text or make XX or something like that
+            }
 
-        if(bpm == -1){
-            //to stuff with UI. Write Text or make XX or something like that
+            mBpmList.add(bpm);
+
+            // we need this here, since ui elements can only be changed within activity thread and
+            // onNewDataAvailable lives inside the bpm estimation thread.
+            // TODO: is this really okay? also synchronized?
+
+            if(getActivity() != null) {
+                getActivity().runOnUiThread(new Runnable() {
+                    @Override
+                    public void run() {
+                        int tmpBPM = (int) (Math.round(mBpmList.lastElement()));
+                        mTextView.setText(String.valueOf(tmpBPM));
+                        mCroller.setProgress(tmpBPM);
+                    }
+                });
+            }
         }
+    }
 
-        mBpmList.add(bpm);
-
-        // we need this here, since ui elements can only be changed within activity thread and
-        // onNewDataAvailable lives inside the bpm estimation thread.
-        // TODO: is this really okay? also synchronized?
-        synchronized (this) {
-            getActivity().runOnUiThread(new Runnable() {
-                @Override
-                public void run() {
-
-                    mTextView.setText(String.valueOf(mBpmList.lastElement()));
-                    mCroller.setProgress((int)(Math.round(mBpmList.lastElement())));
-                }
-            });
-        }
+    /**
+     * Callback function for the sensordata recorded while estimating bpm
+     */
+    @Override
+    public void onEstimationStopped(byte[] sensorData) {
+        //mSensorData = sensorData;
     }
 
     /**
      * Interface for connecting to WorkerFragment
      */
     public interface OnFragmentInteractionListener {
-        void onFragmentStopped(Vector<Double> bpmList);
+        void onFragmentStopped();
     }
 
 }
diff --git a/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/bpmEstimation/AccelerometerData.java b/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/bpmEstimation/AccelerometerData.java
index 55a85b7..1a0fb73 100644
--- a/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/bpmEstimation/AccelerometerData.java
+++ b/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/bpmEstimation/AccelerometerData.java
@@ -15,6 +15,13 @@ public class AccelerometerData {
         this.z = z;
     }
 
+    public AccelerometerData(AccelerometerData other){
+        this.ts = other.ts;
+        this.x = other.x;
+        this.y = other.y;
+        this.z = other.z;
+    }
+
     @Override
     public boolean equals(Object other){
 
diff --git a/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/bpmEstimation/AccelerometerWindowBuffer.java b/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/bpmEstimation/AccelerometerWindowBuffer.java
index a8916b8..5f666a9 100644
--- a/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/bpmEstimation/AccelerometerWindowBuffer.java
+++ b/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/bpmEstimation/AccelerometerWindowBuffer.java
@@ -20,19 +20,20 @@ public class AccelerometerWindowBuffer extends ArrayList<AccelerometerData> {
 
     //TODO: add exception handling. falseArgument if ad has no numeric x,y,z
     public boolean add(AccelerometerData ad){
+        synchronized (this){
+            //do not add duplicates!
+            if (!isEmpty() && getYongest().equals(ad)) {
+                return false;
+            }
 
-        //do not add duplicates!
-        if(!isEmpty() && getYongest().equals(ad)){
-            return false;
+            boolean r = super.add(ad);
+            if (size() > mWindowSize) {
+                removeRange(0, size() - mWindowSize);
+            }
+
+            ++mOverlapCounter;
+            return r;
         }
-
-        boolean r = super.add(ad);
-        if (size() > mWindowSize){
-            removeRange(0, size() - mWindowSize);
-        }
-
-        ++mOverlapCounter;
-        return r;
     }
 
     public boolean isNextWindowReady(){
@@ -44,6 +45,16 @@ public class AccelerometerWindowBuffer extends ArrayList<AccelerometerData> {
         return false;
     }
 
+    public AccelerometerWindowBuffer getFixedWindow(){
+        AccelerometerWindowBuffer other = new AccelerometerWindowBuffer(mWindowSize, mOverlapSize);
+        synchronized (this){
+            for(AccelerometerData data : this){
+                other.add(new AccelerometerData(data));
+            }
+        }
+        return other;
+    }
+
     public AccelerometerData getYongest() {
         return get(size() - 1);
     }
diff --git a/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/bpmEstimation/BpmEstimator.java b/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/bpmEstimation/BpmEstimator.java
index 4d296de..e9dac56 100644
--- a/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/bpmEstimation/BpmEstimator.java
+++ b/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/bpmEstimation/BpmEstimator.java
@@ -44,14 +44,15 @@ public class BpmEstimator {
         //mKalman = new SimpleKalman();
     }
 
-    public double estimate(){
+    //TODO: we use the buffer from outside.. this buffer is continuously updated.. not good!
+    public double estimate(AccelerometerWindowBuffer fixedWindow){
 
         double sampleRate = mSampleRate_ms;
         if(sampleRate <= 0){
-            sampleRate = Math.round(Utils.mean(Utils.diff(mBuffer.getTs())));
+            sampleRate = Math.round(Utils.mean(Utils.diff(fixedWindow.getTs())));
         }
 
-        AccelerometerInterpolator interp = new AccelerometerInterpolator(mBuffer, sampleRate);
+        AccelerometerInterpolator interp = new AccelerometerInterpolator(fixedWindow, sampleRate);
 
         //are we conducting?
         //just look at the newest 512 samples
@@ -90,6 +91,8 @@ public class BpmEstimator {
             int resetAfter = (int) Math.round(mResetLimit_ms / (mBuffer.getOverlapSize() * sampleRate));
             if(++mResetCounter > resetAfter){
                 mBpmHistory.clear();
+
+                //TODO: send signal to clear.
                 mBuffer.clear();
                 mMvg.clear();
                 mResetCounter = 0;
diff --git a/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/network/SensorDataFileSender.java b/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/network/SensorDataFileSender.java
new file mode 100644
index 0000000..52bca7d
--- /dev/null
+++ b/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/network/SensorDataFileSender.java
@@ -0,0 +1,154 @@
+package de.tonifetzer.conductorswatch.network;
+
+import android.content.Context;
+import android.support.annotation.NonNull;
+import android.util.Log;
+
+import com.google.android.gms.tasks.Task;
+import com.google.android.gms.wearable.ChannelClient;
+import com.google.android.gms.wearable.Node;
+import com.google.android.gms.wearable.Wearable;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.util.List;
+
+/**
+ * Created by toni on 15/01/18.
+ */
+
+public class SensorDataFileSender {
+
+    private static final String START_ACTIVITY_PATH = "/start-activity";
+    public static final String TAG = "SensorDataFileSender";
+    private static final String DATA_PATH ="/data";
+
+    private Node mNode;
+    private boolean mChannelOpenend;
+    private ChannelClient.ChannelCallback mSensorDataChannelCallback;
+    private Context mContext;
+
+    public SensorDataFileSender(Context context){
+
+        mContext = context;
+        mChannelOpenend = false;
+        mSensorDataChannelCallback = new ChannelClient.ChannelCallback() {
+
+            @Override
+            public void onChannelClosed(@NonNull ChannelClient.Channel channel, int i, int i1) {
+                super.onChannelClosed(channel, i, i1);
+                //node: this happens in main thread, since anonymous abstract, to prevent make new class extending ChannelClient.ChannelCallback
+
+                mChannelOpenend = false;
+                Log.d(TAG, "Channel is closed on wear");
+
+                //stop showing something on saving screen :D
+            }
+        };
+
+        //find nearest smartwatch
+        getNearestPhone();
+    }
+
+    /**
+     * This function sends a whole SensorDataFile within a byte array.
+     * @param sensorData
+     */
+    public void sendByteArray(byte[] sensorData) {
+
+        if(!mChannelOpenend){
+            //open channel
+            Wearable.getChannelClient(mContext).openChannel(mNode.getId(), DATA_PATH).addOnSuccessListener((ChannelClient.Channel openChannel) -> {
+                Log.d(TAG, "Data channel to phone successfully opened.");
+                mChannelOpenend = true;
+
+                Wearable.getChannelClient(mContext).getOutputStream(openChannel).addOnSuccessListener((OutputStream stream) -> {
+
+                    synchronized (stream){
+                        //write the data into the google service api cloud or whatever that is
+                        try {
+                            stream.write(sensorData);
+                            stream.flush();
+                            stream.close();
+                            Log.d(TAG, "Data send and stream closed." );
+
+                        } catch (IOException e) {
+                            e.printStackTrace();
+                        }
+                    }
+
+                }).addOnFailureListener((Exception e) -> {
+                    Log.d(TAG, "Unable to get outputstream : " + e);
+                });
+
+            }).addOnFailureListener((Exception e) -> {
+                Log.d(TAG, "Unable to open data channel to phone: " + e);
+            });
+
+
+            // Show something on watch "saving" screen
+
+        } else {
+            Log.d(TAG, "Channel is still open, that means the phone still needs time to save stuff from last recording!");
+        }
+
+    }
+
+    public void sendMessage(String Key) {
+
+        if (mNode != null) {
+
+            Task<Integer> sendTask = Wearable.getMessageClient(mContext).sendMessage(mNode.getId(), Key, new byte[0]);
+            sendTask.addOnSuccessListener((Integer i) -> {
+                //Log.d(TAG, "Sending msg success: " + i);
+            }).addOnFailureListener((Exception e) -> {
+                Log.d(TAG, "Sending msg failed with error: " + e);
+            });
+
+        } else {
+            Log.d(TAG, "Phone not found!");
+            //search again for phones within the area
+            //TODO: implement this using a timer. search every 10 seconds or something
+            //getNearestPhone();
+        }
+
+    }
+
+    public void getNearestPhone() {
+
+        mNode = null;
+
+        Task<List<Node>> nodeTask = Wearable.getNodeClient(mContext).getConnectedNodes();
+        nodeTask.addOnCompleteListener((Task<List<Node>> task) -> {
+
+            List<Node> nodes = task.getResult();
+            Node bestNodeId = null;
+
+            //TODO: das ist humbug, bestnodid wird immergenommen nie nearby
+            for (Node node : nodes) {
+                if (node.isNearby()) {
+                    mNode = node;
+                }
+                bestNodeId = node;
+            }
+            mNode = bestNodeId;
+
+            wakeUpPhoneCall();
+        });
+    }
+
+    public void wakeUpPhoneCall(){
+        //start the app on smartphone
+        if(mNode != null){
+            sendMessage(START_ACTIVITY_PATH);
+        }
+    }
+
+    public void register(){
+        Wearable.getChannelClient(mContext).registerChannelCallback(mSensorDataChannelCallback);
+    }
+
+    public void unregister(){
+        Wearable.getChannelClient(mContext).unregisterChannelCallback(mSensorDataChannelCallback);
+    }
+}
diff --git a/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/network/SensorDataFileStreamer.java b/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/network/SensorDataFileStreamer.java
new file mode 100644
index 0000000..60b6cb9
--- /dev/null
+++ b/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/network/SensorDataFileStreamer.java
@@ -0,0 +1,163 @@
+package de.tonifetzer.conductorswatch.network;
+
+import android.content.Context;
+import android.support.annotation.NonNull;
+import android.util.Log;
+
+import com.google.android.gms.tasks.Task;
+import com.google.android.gms.wearable.ChannelClient;
+import com.google.android.gms.wearable.Node;
+import com.google.android.gms.wearable.Wearable;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.util.List;
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.LinkedBlockingQueue;
+
+/**
+ * Created by toni on 15/01/18.
+ */
+
+
+public class SensorDataFileStreamer implements Runnable{
+
+    private static final String TAG = "SensorDataFileStreamer";
+    private static final String DATA_PATH ="/data";
+
+    private volatile boolean mRunning = true;
+    private Node mNode;
+    private boolean mChannelOpenend;
+    private boolean mOutputStreamOpened;
+    private ChannelClient.ChannelCallback mSensorDataChannelCallback;
+    private Context mContext;
+    private OutputStream mOutputStream;
+    private final BlockingQueue<byte[]> mQueue = new LinkedBlockingQueue<>();
+
+    public SensorDataFileStreamer(Context context){
+
+        mContext = context;
+        mChannelOpenend = false;
+        mOutputStreamOpened = false;
+
+        mSensorDataChannelCallback = new ChannelClient.ChannelCallback() {
+
+            @Override
+            public void onChannelClosed(@NonNull ChannelClient.Channel channel, int i, int i1) {
+                super.onChannelClosed(channel, i, i1);
+                //node: this happens in main thread, since anonymous abstract, to prevent make new class extending ChannelClient.ChannelCallback
+
+                mChannelOpenend = false;
+                mOutputStreamOpened = false;
+                Log.d(TAG, "Channel is closed on wear");
+
+                Wearable.getChannelClient(mContext).unregisterChannelCallback(mSensorDataChannelCallback);
+            }
+        };
+
+        //find nearest smartwatch and open channel
+        getNearestPhone();
+    }
+
+    @Override
+    public void run() {
+
+        while (mRunning) {
+            if (mOutputStreamOpened && mChannelOpenend) {
+                try {
+
+                    //TODO: einfach bytestreamwriter direkt hier implementieren. also moutputstream in datastream(moutputstream) und dann direkt über writeint.
+
+                    //TODO: channel is closed before stream was finished
+                    mOutputStream.write(mQueue.take());
+
+                    //TODO: flush after specific file size
+                    //mOutputStream.flush();
+
+                } catch (IOException | InterruptedException e) {
+                    mOutputStreamOpened = false;
+                    //TODO: do something here!
+                    e.printStackTrace();
+                }
+            } else {
+                //open();
+                //TODO: check somewhere if we have a phone or try to reconnect
+            }
+        }
+    }
+
+    /**
+     * This function sends a byte array.
+     * @param sensorData
+     */
+    public void sendByteArray(byte[] sensorData) {
+        if(mRunning && mOutputStreamOpened && mChannelOpenend) {
+            mQueue.offer(sensorData);
+        }
+    }
+
+    private void getNearestPhone() {
+
+        mNode = null;
+
+        Task<List<Node>> nodeTask = Wearable.getNodeClient(mContext).getConnectedNodes();
+        nodeTask.addOnCompleteListener((Task<List<Node>> task) -> {
+
+            List<Node> nodes = task.getResult();
+            Node bestNodeId = null;
+
+            for (Node node : nodes) {
+                if (node.isNearby()) {
+                    bestNodeId = node;
+                    break;
+                }
+                bestNodeId = node;
+            }
+            mNode = bestNodeId;
+
+            if(mNode != null){
+                open();
+            }
+
+        });
+    }
+
+    private void open(){
+
+        if(!mChannelOpenend && mNode != null){
+
+            //register callback
+            Wearable.getChannelClient(mContext).registerChannelCallback(mSensorDataChannelCallback);
+
+            //open channel
+            Wearable.getChannelClient(mContext).openChannel(mNode.getId(), DATA_PATH).addOnSuccessListener((ChannelClient.Channel openChannel) -> {
+            Log.d(TAG, "Data channel to phone successfully opened.");
+            mChannelOpenend = true;
+
+                Wearable.getChannelClient(mContext).getOutputStream(openChannel).addOnSuccessListener((OutputStream stream) -> {
+                    mOutputStream = stream;
+                    mOutputStreamOpened = true;
+
+                }).addOnFailureListener((Exception e) -> {
+                    Log.d(TAG, "Unable to get outputstream : " + e);
+                });
+
+            }).addOnFailureListener((Exception e) -> {
+                Log.d(TAG, "Unable to open data channel to phone: " + e);
+            });
+
+        } else {
+            Log.d(TAG, "Channel is still open, that means the phone still needs time to save stuff from last recording!");
+        }
+    }
+
+    public void close(){
+        try {
+            mRunning = false;
+            mOutputStream.close();
+            mOutputStreamOpened = false;
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+}
diff --git a/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/utilities/FileWriter.java b/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/utilities/ByteStreamWriter.java
similarity index 51%
rename from android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/utilities/FileWriter.java
rename to android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/utilities/ByteStreamWriter.java
index d6d7c6f..376594b 100644
--- a/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/utilities/FileWriter.java
+++ b/android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/utilities/ByteStreamWriter.java
@@ -1,5 +1,7 @@
 package de.tonifetzer.conductorswatch.utilities;
 
+import android.util.Log;
+
 import java.io.ByteArrayOutputStream;
 import java.io.DataOutputStream;
 import java.io.IOException;
@@ -8,20 +10,23 @@ import java.io.IOException;
  * Created by toni on 20/12/17.
  */
 
-public class FileWriter {
-
-    private String mFilename;
+public class ByteStreamWriter {
 
     private ByteArrayOutputStream mByteStream;
     private DataOutputStream mDataStream;
 
-    FileWriter(String filename){
-        mFilename = filename;
+    private final long mFirstTimestamp;
+    int mDataCounter;
+
+    public ByteStreamWriter(){
         mByteStream = new ByteArrayOutputStream();
         mDataStream = new DataOutputStream(mByteStream);
+
+        mDataCounter = 0;
+        mFirstTimestamp = System.currentTimeMillis();
     }
 
-    public void writeDouble(double data){
+    private void writeDouble(double data){
         try {
             mDataStream.writeDouble(data);
         } catch (IOException e) {
@@ -29,15 +34,15 @@ public class FileWriter {
         }
     }
 
-    public void writeString(String data){
+    private void writeChar(char data){
         try {
-            mDataStream.writeChars(data);
+            mDataStream.writeChar(data);
         } catch (IOException e) {
             e.printStackTrace();
         }
     }
 
-    public void writeInt(int data){
+    private void writeInt(int data){
         try {
             mDataStream.writeInt(data);
         } catch (IOException e) {
@@ -45,12 +50,30 @@ public class FileWriter {
         }
     }
 
-    public byte[] getByteArray(){
-        return mByteStream.toByteArray();
+    private void writeLong(long data){
+        try {
+            mDataStream.writeLong(data);
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
     }
 
-    public String getFilename(){
-        return mFilename;
+    public void writeSensor3D(int type, double x, double y, double z){
+        synchronized (this){
+            long writeTime = System.currentTimeMillis() - mFirstTimestamp;
+            writeLong(writeTime);
+            writeInt(type);
+            writeDouble(x);
+            writeDouble(y);
+            writeDouble(z);
+
+            ++mDataCounter;
+        }
+    }
+
+    public byte[] getByteArray(){
+        //Log.d("DataLayerListenerService", "Num data written: " + mDataCounter);
+        return mByteStream.toByteArray();
     }
 
     public void reset(){
@@ -61,6 +84,8 @@ public class FileWriter {
         try {
             mByteStream.close();
             mDataStream.close();
+
+            mDataCounter = 0;
         } catch (IOException e) {
             e.printStackTrace();
         }
diff --git a/android/ConductorsWatch/app/src/main/res/layout/activity_main.xml b/android/ConductorsWatch/app/src/main/res/layout/activity_main.xml
index cb3c332..a679000 100644
--- a/android/ConductorsWatch/app/src/main/res/layout/activity_main.xml
+++ b/android/ConductorsWatch/app/src/main/res/layout/activity_main.xml
@@ -46,7 +46,7 @@
             android:layout_width="match_parent"
             android:layout_height="match_parent"
             android:gravity="center"
-            android:text="240"
+            android:text="80"
             android:textStyle="bold"
             android:textColor="#158b69"
             android:textSize="40sp"/>