Introduction

This is the final project for CIS8590. It's an Android application to evaluate the accuracy and energy efficiency with different kinds of location sensors and some auxiliary sensors.

In this project, we propose a method to coordinate the usage of GPS and WiFi based on the current moving status of the device. In order to get the moving status of the device, we use accelerometer and magnetic sensors to detect the orientation changes of the device. Current supported moving status includes:

• Turning
• Walk straight

Following is the information about the development environments:

• CentOS 6.5
• Eclipse + Android ADT
• Android SDK

Application Structure

There are 3 main componets in this application:

• Main Activity - SensiLoc
• Sensor Service - SensiService
• Locate Service - LocateService

The functions of each componets are as follows:

1. SensiLoc Get user inputs including the experiment time, frequency of location request and the method to locate. After start button clicked, the availability of GPS and Network will be checked according to the method selected. Location Service will be started after the check. In addition to Locate Service, Sensor Service will be also started if adaptive method selected.
2. Sensor Service In the onCreate() callback, the handlers of sensors (accelerometer and magnetic field) can be gotten from the Sensor Manager and listeners will be registered for the updates from respect sensors. So in the onSensorChanged() callback of the SensorListener, the update value of acceleration and magnetic field force can be extracted from the SensorEvent. Use both acceleration and magnetic field values we can get the rotation matrix. After get the rotation matrix, we remap the device coordinate system to the world coordinate system. Then we get the orientation of the mobile. Here we need the azimuth value of the orientation to detect the moving status of the device.
3. Locate Service After extracting the parameters in the Intent from the main Activity,

Acknowlegement

Known Problems

1. Setup linux to detect your hardware device If you're developing on linux OS (Ubuntu, CentOS), you need to add a udev rules file that contains a USB configuration for the device you want to use for development.

• Search vender ID of your device
  Plug your device and look up the vendor ID using command lsusb, you'll get information about your device like this:
  

  Bus 001 Device 007: ID 22b8:428c Motorola PCS
  

  
  _22b8_ is the vendor ID of my device.
• Create USB udev file for your device
  The file you need to create is: /etc/udev/rules.d/51-android.rules.
  Use this format to add each vendor to this file:
  

  SUBSYSTEM=="usb", ATTR{idVendor}=="0bb4", MODE="0666", GROUP="plugdev"