Software Specifications for EvAAL Competitors

On-site track

Competitors of EvAAL 2015 have to code an Android application targeted for smartphones (no tablet are allowed) that:

• computes the location of the target user during the measurement session
• reports the estimated position twice per second to the measurement application (the StepLogger).

We provide two Android-based applications:

The StepLogger provides two basic functionalities:

1. a logging service designed to log the position computed by the applications of the competitors  (Section 1) as well as the time you press the buttons shown
2. a GUI to perform the measurements (Section 2)

The StepLoggerClient provides one basic feature:

1. a fake localization system generating fake positions and invoking the logging system of StepLogger

APKs are available for download here.

Source code of the appliations StepLogger and StepLoggerClient are available:

https://ala.isti.cnr.it/home/svn/software/localization/Android/EvAAL15/

svn://ala.isti.cnr.it/software/localization/Android/EvAAL15

with username : competitor and password: competitor

1.    StepLogger Logging Interface

StepLogger provides a simple service for the applications of the competitors. The service is implemented with one single method named:

void logPosition(in long timestamp, in double x, in double y, in double z); 

which is provided by the StepLogger app; the moethod should be invoked through the AIDL interface. Specifically, competitors must add the StepLogger AIDL file to their Android project and invoke the logPosition method twice per second.

Every time the competing app calls logPosition StepLogger logs the following information:

• Time stamp: this time expressed in seconds (please refer to the currentTimeMillis() provided by the Java System class)
• Coordinates x, y, z

This information is stored in the file positions.log, as detailed below under “StepLogger Logging mechanism”.

1.1.  How to use the StepLogger AIDL interface

• Download the StepLogger AIDL file from the SVN location
• The AIDL file must be placed on the aidl folder under your Android project

• Add the AIDL file in the right Java package, namely it.cnr.isti.steplogger

• Invoke the logPosition method by following these steps:

1. Create an Intent object
2. Set the class name of the intent object with:
   1. BOUNDSERVICE_PACKAGE = "it.cnr.isti.steplogger";
   2. BOUNDSERVICE_CLASS = ".StepLoggerService";

• Invoke the bindService(…) method provided by Android OS in order to bind to the service that matching with BOUNDSERVICE_PACKAGE and BOUNDSERVICE_CLASS

void bindService(in Intent intentService, in ServiceConnection mConnection, in int flags); 

You should download the apk and the source code of the stub StepLoggerClient application, which intended to provide an example of how the competing application should interact with the StepLogger. StepLoggerClient shows a GUI with two buttons: START LOGGING POSITION and STOP LOGGING POSITION.

Note: Since StepLoggerClient invokes a method provided by the StepLogger app, you have to first start a new measurement session (See Section 2.1)

When you click on START LOGGING POSITION:

1. The StepLoggerClientActivity creates an intent object and it sends the intent to the StepLoggerClientService
2. The StepLoggerClientService manages the intent received with the following steps:

• It creates an intent for invoking the logPosition service

if (intent != null) {

intentService.setClassName(BOUNDSERVICE_PACKAGE, BOUNDSERVICE_PACKAGE + BOUNDSERVICE_CLASS);

}

• It binds to the service with the Android system call:

 bindService(intentService, mConnection , Context.BIND_AUTO_CREATE );

• It invokes twice per second the logPosition with coordinated of x,y and z generated randomly

while (mustRun) {    if(!isBound){    // Try to rebind every 1000 msec       timer.schedule(new TimerTask() {          @Override          public void run() {             bindService(intentService, mConnection , Context.BIND_AUTO_CREATE ); }       }, 1000);    } else {       try{       // mService could still be null even if bound correctly          if  (mService != null) {          // Send to the Bound Service method logPosition          // current timestamp and random coords             Log.d(LOG_TAG, "logPosition called");             mService.logPosition(System.currentTimeMillis(), Math.random() * 1000,                Math.random() * 1000, Math.random() * 1000);          }          Thread.sleep(INTERVAL);       } catch (Exception e) {            Log.e(LOG_TAG, e.getMessage());            e.printStackTrace();       }    } } 

2.    StepLogger GUI

StepLogger provides a GUI to be used by competitors to perform the measurement sessions. The actor will walk along a predefined path within the evaluation site and he/she click the button displayed by StepLogger when stepping over the markers placed on the floor. The button displayed on the screen shows the same label of the markers positioned on the floor, so that the actor can double-check when to press the button. Every time the button is pressed, StepLogger logs the following information :

• Time stamp: this time is gathered from the clock of the smartphone running StepLogger
• The label displayed when the button is pressed

These information are stored in the file buttonsPressed.log, please refer to the “StepLogger Logging mechanism” section for information about the logs.

2.1.  How to start a new measurement session

FIRST: copy the this INI file under the Download directory of your phone. For example: /storage/emulated/0/Download/

• Install StepLogger and StepLoggerClient applications. Please remember to enable installation from unknown sources in you smartphones, otherwise you smartphone will prevent the installation of third-party applications.
• Search for StepLogger and StepLoggerClient applications on your smartphone. Usually, after the installation of a new applications, you can find them by browsing the application menu.
• Move StepLogger and StepLoggerClient on the Home page screen