Published September 21, 2017 © GPL3+

LeapKid

Solution using the DPS130 pressure sensor in a device that can help to protect either infants or toddlers from injuries.

IntermediateFull instructions provided16 hours941

Things used in this project

Hardware components

Infineon Sensor Hub Nano

I am using the Android libraries for DPS310 devices provided by Infineon

Story

What's the LeapKid?

There are numerous well-known accidents when a child climbs on a chair, rock or window and falls down which in some cases can lead to tragic consequences. As a parent I realize that it is impossible to track each step of your little baby (especially when you need to take care of more than one kid at the same time). We need to be careful and look after children if they play safely. In my opinion DPS130 sensor with its tremendous accuracy enables us to create a great and helpful application in mentioned domain. The idea is as follows:

How does it work?

My solution is based on the Sensor Hub Nano (EVAL SHNBV01) module from Infineon. This board could be easily attached to a diaper for instance. Once we establish BLE connection between module and our smartphone with Android system, we can enable this device. Application on the smartphone is responsible for communicating with the module, and setup all necessary details as desired. Since the altitude measurements are based on the pressure sensors so the first values which we are going to obtain are relative to the sea level. Because of that we have to run the calibration by pressing the "Set Reference level" button. It allows us to adjust the readings to our external conditions. Then we need to trigger main workflow of the application (tracking the altitude) by pressing "Start Watching" button. If child climbs above some safe threshold (i.e. 40cm or 15.7”) above level "0" (reference level set before) the audio notification will be fired up on our smartphone. Alarm will occur as long as we do not hit the "Stop Watching" button.

Hardware

For this project I have used the Sensor Hub Nano ( EVAL SHNBV01) see below.

Fig1. Sensor Hub module

Fig2. Block diagram of Sensor Hub

Sensor Hub Nano contains everything from the hardware stand point which I need to realize LeapKid concept.

The solution is build on top of the Pressure Sensor DPS310, BLE Module, Battery, and MCU which takes care to read the data from the sensor and push them via BLE to the smartphone.

The accuracy of the DPS310 is outstanding and allows to create an application which was never considered before.

Worth to mention is that the pressure sensor has a great advantage over the accelerometers in this kind of application because:

Level reading are independent from position how it is assembled on the object which we want to monitor

Accelometers measure the change in the movement so the are always relative. Pressure sensor can give you a chance to use the absolute values which are perfect this this application.

Also very interesting material why DPS310 pressure is different compare to other sensors from other vendors and what makes them so accurate. See link below:

https://www.infineon.com/dgdl/Infineon-DPS310+Article+EE+Times-ART-v01_00-EN.pdf?fileId=5546d462584d1d4a015886c29da25e91

Because of this accuracy, the many new technical solution can be done. One of them is LeapKid.

Software

For this project I have used Android Studio (first time in my life) and Android libraries for this Sensor Hub which are available thanks to the Infineon team. Based on this information I was able to create my first Android application which I would like to describe in details below:

Fig2. First Screen

Application shows the Device number and after pressing the "Connect" button allows to start collecting the information from the Sensor Hub module.

Fig3. Second screen once we connect

On Fig3. you can find that the values being obtained for altitude are relative to the sea level. In order to correct them we mount the module on the level we want to treat as a "ground floor". By pressing the "Set Reference Level" button the offset is being set. After that operation we get the following screen:

Fig4. Reading after adjust offset

Fig5. Working system

On Fig4/5 we can see that the system is ready and operate properly.

Rest of the logic behind it is simple since the operator (parent) cannot spend too much time on calibrating the device.

When you press the "Start Watching" button the system tracks if the altitude is not higher than 0.4m [15.7”]. If it is, then it turns on the audio alarm on our smartphone. Thanks to that it lets us know the child reached the safe threshold. Alarm will work as long as we do not deactivate it by pressing the "STOP Watching" button.

Core functionality

 public void onSensorDataReceived(SensorHub sensorHub, final SensorEvent sensorEvent) {
// measure altitude
 if (sensorEvent.getDataId().equals("a")) {
Alt = sensorEvent.getSensorValue();
 Alt_adjust = (Alt - Alt_offset); // Setup the altitude level with correct offset
 if (Alt_adjust < 0.15) Alt_adjust = 0; // Ignore changes of the altitude below 15cm
 if(Active) { // here we activate an alarm if requested conditions happen
 if (Alt_adjust >= 0.4) alarm_on(); // we will engage the sound alarm if the altitude will reach 40cm or more.
 }
 Altitude.setText(Alt_adjust + "m");
 }
            }
        });
 sensorHub.connect();
 btnSet.setOnClickListener(new View.OnClickListener() {
@Override
 public void onClick(View v) { // Activate watching
 Active = true;
 }
       });
 btnReset.setOnClickListener(new View.OnClickListener() {
@Override
 public void onClick(View v) { // Deactivate alarms
 Active = false;
 alarm_off();
 }
       });
 btnOffset.setOnClickListener(new View.OnClickListener() {
@Override
 public void onClick(View v) { // setup the offset for altitude measurements
 Alt_offset = Alt;
 }
       });
}
private void alarm_on() {
       AudioManager audioManager = (AudioManager) getSystemService(AUDIO_SERVICE);
        float actualVolume = (float) audioManager
                .getStreamVolume(AudioManager.STREAM_MUSIC);
        float maxVolume = (float) audioManager
                .getStreamMaxVolume(AudioManager.STREAM_MUSIC);
        float volume = actualVolume / maxVolume;
 // Is the sound loaded already?
 if (mLoaded) {
 mSoundStreamId = mSoundPool.play(mSoundID, volume, volume, 1, -1, 1f);
 }
 Active = false;
 }  // function responsible for sound alarm activation
 private void alarm_off() {
mSoundPool.stop(mSoundStreamId);
 Active = false;
 } // function responsible for deactivate the sound alarm
}

Note: The libraries provided by Infineon allow to set the precision for your application. In my case do to the fact that I am looking on high accuracy I setup sensor in the following way:

 public void onConnected(SensorHub sensorHub) {
   sensorHub.setMode("mode", "bg");
   sensorHub.setMode("prs_mr", "128");
   sensorHub.setMode("prs_osr", "128");
   sensorHub.start();
}

Video

https://youtu.be/jrFKvNqd9Ls

Summary

It was a great experience to evaluate the DPS310 sensor and it capability. I see great potential to use this sensor in applications where we never before consider a pressure sensor due to low accuracy. Now with this sensor we can create the solution like i.e

Respiratory analyses

More precise weather forecast

Flying objects precise height measurements

Allow to check if the working area is hermetic ( i.e in bio-hazard materials )

etc...

Note: BLE and single board solution drastically improve life of battery making a solution reliable for entire needed time.

Potential improvements / next steps ...

The system could be equipped with the Temp/Humidity sensor which could give us additional information if there is a need to change the diaper.

BLE connection between application and module works in the background.

Audio notification if the link between phone and module was dropped for some reason.

Deactivate alarms if the jumps in altitude happen especially from bottom to top (i.e when parent lift the child from the "zero" level).

Add option to change the safe threshold.

Make it immune to occasional changes (i.e. child is jumping).

Add additional accelometer which can detect the fall ( could be used for elder people )

Code

package com.example.jacek.leapkid;

import android.bluetooth.BluetoothAdapter;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Toast;
import android.widget.Button;
import android.widget.TextView;
import android.view.View;
import android.bluetooth.BluetoothDevice;

import java.util.ArrayList;
import java.util.Set;


public class DeviceFinderActivity extends AppCompatActivity {

    private Button btnConnect;
    private TextView tvDevice;
    private String deviceAddress;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.leapkid);

        btnConnect = (Button) findViewById(R.id.btn_connect);
        tvDevice = (TextView) findViewById(R.id.tv_device);

        btnConnect.setOnClickListener(new View.OnClickListener(){

            @Override

            public void onClick(View v) {
                connect();
            }

        });

       Set<BluetoothDevice> allDevices = BluetoothAdapter.getDefaultAdapter().getBondedDevices();

        ArrayList<BluetoothDevice> myDevices = new ArrayList<>();

        for(BluetoothDevice d: allDevices)
        {
            if(isMyDevice(d))
                myDevices.add(d);

        }
        if(myDevices.size()==0){
            Toast.makeText(getApplicationContext(), "No Device found", Toast.LENGTH_LONG).show();
            finish();
        }
    tvDevice.setText("Device:" + myDevices.get(0).getName() + "\t" + myDevices.get(0).getAddress());
        deviceAddress=myDevices.get(0).getAddress();


    }



    private boolean isMyDevice(BluetoothDevice d){
        String deviceName = d.getName().toLowerCase();

        return deviceName.equals("ifx_nanohub");
    }
    void connect(){
Intent intent = new Intent(getApplicationContext(), MainActivity.class);
        intent.putExtra("deviceAddress", deviceAddress);

        startActivity(intent);
    }
}

package com.example.jacek.leapkid;


import android.media.AudioManager;
import android.media.SoundPool;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;


import com.infineon.sen.comm.Model.Mode;
import com.infineon.sen.comm.SensorEvent;
import com.infineon.sen.comm.SensorHub;
import com.infineon.sen.comm.SensorHubListener;


public class MainActivity extends AppCompatActivity {


    private TextView Altitude;
    private Button btnSet;
    private Button btnReset;
    private Button btnOffset;

    ////////////////// Variables ///////////////////////////////////
    private double Alt = 0; // Variable containing Altitude value received from sensor Hub
    private double Alt_offset = 0; // Variable which setup the reference level
    private double Alt_adjust = 0; // Biased value of altitude based on offset value
    private boolean Active = false; // Boolean variable supporting set or reset the alarms.

    private SoundPool mSoundPool;
    private int mSoundID;
    boolean mLoaded = false;
    private int mSoundStreamId;



    @Override

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main_layout);

        Altitude = (TextView) findViewById(R.id.Altitude);
        btnSet = (Button) findViewById(R.id.btn_Set);
        btnReset = (Button) findViewById(R.id.btn_Reset);
        btnOffset = (Button) findViewById(R.id.btn_Offset);

        ///////////////////Setup a sound control /////////////////////

        this.setVolumeControlStream(AudioManager.STREAM_MUSIC);

        // Load the sound
        mSoundPool = new SoundPool(10, AudioManager.STREAM_MUSIC, 0);
        mSoundPool.setOnLoadCompleteListener(new SoundPool.OnLoadCompleteListener() {
            @Override
            public void onLoadComplete(SoundPool soundPool, int sampleId,
                                       int status) {
                mLoaded = true;
            }
        });

        mSoundID = mSoundPool.load(this, R.raw.alarm, 1);
        //////////////////////////////////////////////////////////////


        String deviceAddress = getIntent().getStringExtra("deviceAddress");

        SensorHub sensorHub = new SensorHub(getApplicationContext(), deviceAddress);

        sensorHub.addSensorHubListener(new SensorHubListener() {
            @Override
            public void onConnected(SensorHub sensorHub) {

                sensorHub.setMode("mode", "bg");
                sensorHub.setMode("prs_mr", "128");
                sensorHub.setMode("prs_osr", "128");
                sensorHub.start();
            }

            @Override
            public void onDisconnected(SensorHub sensorHub) {

                // Toast.makeText(getApplicationContext(),"Disconnect to" + sensorHub.getName(). Toast.LENGTH_LONG.show());

            }

            @Override
            public void onConnectionError(SensorHub sensorHub) {
                //  Toast.makeText(getApplicationContext(),"Connection Error" + sensorHub.getName(). Toast.LENGTH_LONG.show());

            }


            @Override
            public void onModeChanged(SensorHub sensorHub, Mode mode) {

            }

            @Override
            public void onSensorDataReceived(SensorHub sensorHub, final SensorEvent sensorEvent) {


                // measure altitude
                if (sensorEvent.getDataId().equals("a")) {

                    Alt = sensorEvent.getSensorValue();

                    Alt_adjust = (Alt - Alt_offset); // Setup the altitude level with correct offset

                    if (Alt_adjust < 0.15) Alt_adjust = 0; // Ignore changes of the altitude below 15cm

                    if(Active) { // here we activate an alarm if requested conditions happen

                         if (Alt_adjust >= 0.4) alarm_on(); // we will engage the sound alarm if the altitude will reach 40cm or more.
                    }
                    Altitude.setText(Alt_adjust + "m");

                }
            }
        });
        sensorHub.connect();

        btnSet.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) { // Activate watching

              Active = true;

            }

        });

        btnReset.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) { // Deactivate alarms

                Active = false;
                alarm_off();

            }

        });

        btnOffset.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) { // setup the offset for altitude measurements

                Alt_offset = Alt;

            }

        });

}


    private void alarm_on() {

        AudioManager audioManager = (AudioManager) getSystemService(AUDIO_SERVICE);
        float actualVolume = (float) audioManager
                .getStreamVolume(AudioManager.STREAM_MUSIC);
        float maxVolume = (float) audioManager
                .getStreamMaxVolume(AudioManager.STREAM_MUSIC);
        float volume = actualVolume / maxVolume;
        // Is the sound loaded already?
        if (mLoaded) {
            mSoundStreamId = mSoundPool.play(mSoundID, volume, volume, 1, -1, 1f);
        }
        Active = false;
    }  // function responsible for sound alarm activation
    private void alarm_off() {

        mSoundPool.stop(mSoundStreamId);
        Active = false;
    } // function responsible for deactivate the sound alarm

}

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

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

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

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

</manifest>

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@android:color/background_light">

    <TextView
        android:id="@+id/tv_device"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="17dp"
        android:text="Device ID:"
        android:layout_above="@+id/btn_connect"
        android:layout_alignParentStart="true"
        android:layout_marginStart="31dp" />

    <Button
        android:id="@+id/btn_connect"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentStart="true"
        android:elevation="0dp"
        android:text="Connect" />

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/imageView"
        android:layout_centerHorizontal="true"
        android:alpha="1"
        android:text="Watch for Children"
        android:textAppearance="@style/TextAppearance.AppCompat.Body2" />

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/tv_device"
        android:layout_alignParentStart="true"
        app:srcCompat="@drawable/eye" />
</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@android:color/background_light">

    <Button
        android:id="@+id/btn_Set"
        style="@style/Widget.AppCompat.Button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:background="@android:color/holo_orange_light"
        android:text="Start Watching" />

    <TextView
        android:id="@+id/Altitude"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/btn_Set"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="168dp"
        android:maxLength="6"
        android:textAppearance="@style/TextAppearance.AppCompat.Display1" />

    <Button
        android:id="@+id/btn_Reset"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentStart="true"
        android:background="@android:color/holo_blue_light"
        android:text="Stop Watching" />

    <Button
        android:id="@+id/btn_Offset"
        style="@style/Widget.AppCompat.Button.Colored"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/Altitude"
        android:layout_marginTop="44dp"
        android:background="@android:color/holo_green_dark"
        android:text="SET Reference Level"
        android:layout_alignParentStart="true"
        android:layout_alignParentEnd="true" />

    <TextView
        android:id="@+id/Level"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/btn_Offset"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="48dp"
        android:text=" Level [m]:" />

</RelativeLayout>

Credits

Jacek Pieczaba

6 projects • 7 followers

Hardware design engineer;Technology enthusiast;

LeapKid

Things used in this project

Hardware components

Story

What's the LeapKid?

How does it work?

Hardware

Software

Video

Summary

Potential improvements / next steps ...

Schematics

Flow Chart

Code

Device Finder

Main Activity

Android Manifest

LeapKid Layout

LeapKid layout

Credits

Jacek Pieczaba

Comments

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LeapKid

LeapKid

Things used in this project

Hardware components

Story

What's the LeapKid?

How does it work?

Hardware

Software

Video

Summary

Potential improvements / next steps ...

Schematics

Flow Chart

Code

Device Finder

Main Activity

Android Manifest

LeapKid Layout

LeapKid layout

Credits

Jacek Pieczaba

Comments

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