Is it possible to measure the how far the phone travels vertically

Question

I\'m just wondering if it is possible / where would I get started in measuring the upwards and downwards movement of an Android device. I\'d need it to be as accurate as possibl

Answer 1

Before going to solution, I would split the solution in small assets and put the puzzle for solution

1. We need to listen to phone sensors
2. We need to check phone is in vertical position or not
3. We need to make a time counter that register the phone vertically and count up
4. We need to display the time on screen

For step one, I would implement SensorEventListener to our class, this will allow us to use onSensorChanged method.

@Override
public void onSensorChanged(SensorEvent event) {
    if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER) {
        listenToSensors(event);
    }
}

private void listenToSensors(SensorEvent event) {
    if (isPhoneVertical(event)) {
        timeCounter();
        if (mStatus) {
            mStartTime = getStartTime();
            mStatus = false;
        }
    } else {
        if (!mStatus) {
            mTotalTime = getDiffTime() + mTotalTime;
            mStatus = true;
        }
    }
}

For step two, I have built a method called isPhoneVertical to check if our phone is in vertical way or not, it is primarily checking the y axis. You can change the steep degree by changing maxVertical. Less value her less steep, 0 means the phone should almost be 100% vertical. For my test it is set to 3.

private boolean isPhoneVertical(SensorEvent event) {
    float[] values = event.values;
    double y = values[1];
    // do not change this value
    double yAxisInitValue = 10.0;
    double verMargin = yAxisInitValue - maxVertical;

    return y >= verMargin;
}

For step 3 I have made few method to check start time and stop time and update a global variable that keep track of time in seconds.

private long getStartTime() {
    return System.currentTimeMillis() / 1000;
}

private long getDiffTime() {
    return getStartTime() - mStartTime;
}

For step 4 I have made a regular runOnUiThread to update the time on screen.

private void timeCounter() {
    runOnUiThread(new Runnable() {
        @Override
        public void run() {
            mView1.setText("Phone has been vertical for: " + getDiffTime() + " seconds");
            mView2.setText("The total time: " + (mTotalTime + getDiffTime()) + "");
        }
    });
}

That said this solution is to illustrate how this goal can be reached, I am sure it can be done different ways. But I wanted to show the logic behind the solution.

And here is a screen shot of the app that counts the time for each time the phone is vertical and total time it has been vertical.

The solution including some explanations:

MainActivity.java

public class MainActivity extends Activity implements SensorEventListener {
    private SensorManager mSensorManager;
    private Sensor mAccelerometer;
    private TextView mView1, mView2;
    private long mStartTime;
    private long mTotalTime;
    private boolean mStatus = true;
    // less value her less steep, 0 means the phone should almost be 100% vertical
    // try it out
    private double maxVertical = 3.0;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN);

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mView1 = (TextView) findViewById(R.id.textView1);
        mView2 = (TextView) findViewById(R.id.textView2);

        mSensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
        mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
    }

    @Override
    public void onSensorChanged(SensorEvent event) {
        if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER) {
            listenToSensors(event);
        }
    }

    private void listenToSensors(SensorEvent event) {
        if (isPhoneVertical(event)) {
            timeCounter();
            if (mStatus) {
                mStartTime = getStartTime();
                mStatus = false;
            }
        } else {
            if (!mStatus) {
                mTotalTime = getDiffTime() + mTotalTime;
                mStatus = true;
            }
        }
    }

    // This method return true only for specific phone orientation
    // y axis for vertical orientation
    private boolean isPhoneVertical(SensorEvent event) {
        float[] values = event.values;
        double y = values[1];
        // do not change this value
        double yAxisInitValue = 10.0;
        double verMargin = yAxisInitValue - maxVertical;

        return y >= verMargin;
    }

    private long getStartTime() {
        return System.currentTimeMillis() / 1000;
    }

    private long getDiffTime() {
        return getStartTime() - mStartTime;
    }

    // update steps in user interface
    private void timeCounter() {
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                mView1.setText("Phone has been vertical for: " + getDiffTime() + " seconds");
                mView2.setText("The total time: " + (mTotalTime + getDiffTime()) + "");
            }
        });
    }

    @Override
    public void onAccuracyChanged(Sensor sensor, int accuracy) {

    }

    @Override
    protected void onResume() {
        super.onResume();
        mSensorManager.registerListener(this,
                mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER),
                SensorManager.SENSOR_DELAY_NORMAL);
    }

    @Override
    protected void onPause() {
        super.onPause();
        // if you want to collect data while mobile screen off, just disable the
        // following line, the app will still collecting sensor data
        mSensorManager.unregisterListener(this);
    }
}

Activity_main.xml

I will leave some link for reading as well.

• https://developer.android.com/reference/android/hardware/SensorManager.html
• http://www.livescience.com/40103-accelerometer-vs-gyroscope.html
• https://physics.stackexchange.com/questions/41653/how-do-i-get-the-total-acceleration-from-3-axes
• https://code.tutsplus.com/tutorials/how-to-recognize-user-activity-with-activity-recognition--cms-25851
• http://www.vogella.com/tutorials/AndroidSensor/article.html
• How to get Android phone orientation matching human orientation?

If you think I might add more information that can help you further with your question please let me know. It is also unclear if you was looking for walking detection/counter, if that is some thing you are interesting in, look at following answers/links.

• Activity Recognition Api
• How to detect walking with Android accelerometer
• how to calculate exact foot step count using accelerometer in android?
• Detect Movement Accurately using Accelerometer in Android

and GitHub source codes

• https://github.com/bagilevi/android-pedometer
• https://github.com/tartakynov/robowalk