Sensors on Smart Phones Rachel Shah and Varsha Vuyyuru Dr.Qing Chao Zheng Lu UTK CURENT

Overview 1 Objective Our goal was to learn how sensors such as the magnetometer and accelerometer were used to track location. From this, we would be able to create a code that would track our location.

Overview Programming Basics of Python Develop a Number Game Phone Hardware Capture Phone Motion Data Applying Code to Android Phone Phone Connectivity Using Wi-Fi and GPS for Localization Tracking Locations Mapping out your path

Basics of Python 4 Basics of Python include:  Print statement  For Loop  While Loop  Opening and closing files

Number Game 5 Setting Variables and User Input y = 5 y = int(raw_input(“input a number”) While Statement While (x! = y): If (x > y): x = int(raw_input(“guess a smaller number”)) else: x = int(raw_input(“guess a larger number”)) Print Statement print “correct answer!” raw_input(“good Job!”)

Python Programming on Androids 6 Python programming language is very practical due to its ease to use and ability to create codes and applications.

Accelerometer An accelerometer is a device that measures acceleration in all dimensions. It can sense tilt and movement and has 3 axis's. An application that uses the accelerometer is the labyrinth game. 7

Accelerometer Code 8 f = open(“droid”,”w”) d.startSensingTimed( 1,100) Open File and Start Timer for I in range(40): a = d.sensorsReadA ccelerometer() a = a.result[0] f.write(“{0}\n”.f ormat(a)) Print I Time.sleep(1) For Statement d.stopSensing d.makeToast(finished” ) f.close)() Stop Timer and Close File

Accelerometer Readings 9 Here, the accelerometer measures the steps taken by measuring the frequency.

Magnetometer 10 Magnetometers are used to measure magnetization of a material or to measure the strength of a magnet,

Magnetometer 11 Import time d = android.Android)() d.makeToast(“start!”) f = open(“droid,”w”) d,startSensingTimed(1,100 ) Set to Android, Open File and Start Timer For I in range(40) a = d,sensorsReadMagnet ometer Mag = a,result[0] Magb = a,result[1] Magc = a.result[2] f.wirte(“{0} {1} {2}\n”.format(mag,m agb,magc)) Print 1 Time.sleep(!) Reading the Magnetometer D,stopSensing() d.makeToast(“finished!”) f.close() Stop Timer and Close File

Data for Magnetometer 12

How a GPS Works GPS satellites transmit information about their current time and position at regular intervals These signals are intercepted by your GPS receiver which calculates how far away the satellite is based on time it took for the message to arrive 13

GPS Code Setting the code to Android Import android Import time d = android.Android() d.startLocating() Read location data for I in range(10) Time.sleep(2) a = d.readLocation() Print a if not a.result: continue Reading Coordinates if “gps” in a.result: x = a.result[“gps”][‘latitude’] y = a.result[‘gps’][longitude’] print d.geocode(x,y) print “ ” d,stiopLocating() 14

The RSSI (Received Signal Strength Indication) takes signals your phone detects from nearby access points It then refers to a database where it refers to signal strength to get distance. The RSSI determines where you are in relation to those access points 15 How to get your Location Based off of Wi-Fi

Tracking and Mapping your Location Using a code similar to the previous GPS, we were able to receive coordinates and map our location. 16

Future Technologies With the growing popularity of GPS, there are many advance to come with it. For example,  Self-driving cars  Self-driving aircraft for military use 17

THANK YOU! 18

19 QUESTIONS?