CREATING AN EFFECTIVE PROXIMITY ALARM USING HOUSEHOLD ITEMS

By Sarah V.

ABOUT ME Music, math and science are my favorite subjects I plan on studying engineering in college Academics

Straight A student I have been placing in science fairs since 1st grade

Since 5th grade my projects have focused on Wi-Fi antenna design and wireless communication protocols

My interest was sparked by the need to improve the performance of my home wireless networking system

Belonged to an FLL team 6th – 7th grade and the team went to state each of those years

I convinced my parents to create the team I learned how to approach, solve and break down physical tasks and problems into simple

programming steps in NXTg I also learned how to research complicated topics including nanotechnology, energy

sources and climate change, and how to apply what I learned to solve problems in my community

Clubs Algebra II Team National Honor Society

Symphonic Orchestra I am a 2nd violinist Over Christmas Break we had the privilege of playing at the Midwest Conference

as 1 of 2 full orchestras in the nation that were chosen Schools

Full time 10th grade student at Satellite High School I now take Computer Programming I with Mr. Jordan on FLVS

I have been taking FLVS classes since the end of my 8th grade year

AN INTRODUCTION Purpose:

To create an alarm that will alert someone if they leave any items (or children) in a car

In 2010, more than 49 children died from being left in hot cars I had trouble with leaving my violin in my hot car in the overbearing Florida sun

Other Purposes Make sure that young children do not wander too far away Make sure that you luggage does not wander too far away

Design Criteria Constructed of items found around the house Lightweight, compact Reasonable range (defined as alarming within an easily retrievable

distance) Dependable (defined as alarming every time communication

between the devices is broken) Hypotheses:

If the master device (NXT) and slave device (i-gotU) are separated, then the master device will alarm when the Bluetooth signal is lost, alerting the user.

If the distance to alarm from each of the four sides of the NXT to the i-gotU is measured, the distances will be equal.

If the distance to alarm is based upon GPS values rather than Bluetooth signal loss, then the distance to alarm will be less variable.

BASIC BACKGROUND INFORMATION Bluetooth

Short range wireless communication technology Known for it’s low power consumption and low cost Uses the 2.4 GHz ISM (Industrial, Scientific, and Medical) frequency band Most devices can automatically connect up to other Bluetooth devices

Lego NXT Bluetooth (Uses a V2.0 class 2 device) enabled, programmable micro

computer made by the Lego cooperation Has an LCD window to display images/text and a speaker to play sound files Uses NXT-G and RobotC programming languages Typically used to build LEGO robots

i-gotU GPS Logger and Photo Tagger Bluetooth (Uses a V2.0 class 2 device) enabled GPS (Global Positioning

System) Can send GPS coordinates to another device via Bluetooth

RobotC Used to Program the NXT Closely related to the C-programming language (‘written’ not graphical programming

language) GPS (Global Positioning System)

Satellite based navigation system Most commercial users can expect at least +/- 10 meters Satellites send their time and location to a receiver (your GPS system) and the receiver

calculates its location Market Review

Several other proximity alarms were found on the internet

THE CONCEPT

Devices in Range – No Alarm

Devices Not in Range – Alarm

nXT

A B C USB

1 2 3

LEGO

4

i-gotU

i-gotU

nXT

A B C USB

1 2 3

LEGO

4

THE CONCEPT CONT.

MATERIALS & METHODSMaterials One HP G70-460US Notebook PC running RobotC One Lego Mindstorms NXT running RobotC One i-gotU USB GPS Logger and Photo Tagger (Mobile

Action, GT-200) The proximity alarm tests were conducted in:

an open field with few signal interferences (experimental control) in a suburban environment (home driveway to front door) with

typical signal interferences (Wi-Fi and physical obstacles) One 50 m tape measure was used to determine the

distance at which the Bluetooth signals were lostMethods A  RobotC program for the NXT was written and debugged

The objective of the program was to monitor the Bluetooth signal between the NXT and i-gotU, and to alarm and display time and GPS coordinates of the i-gotU when the Bluetooth signal was lost

The program was tested and adjusted to optimize communication between the NXT and i-got-U. Figure 4 contains the program flow chart

MATERIALS & METHODS The optimum range and reliability of the proximity alarm were determined at the

soccer fields where there were few signal interferences (ex. physical obstacles and other wireless devices) Figure 1 contains a conceptual diagram of the signal path and equipment Figure 2 contains a Google Earth image of the field testing site The distance to alarm was measured forty times from each side (top, right, bottom, left) of

the NXT to the i-gotU In this scenario, the NXT remained stationary while the i-gotU was moved out of range The Interquartile Range (IQR) test was used to identify outliers in each data set (Donnelly,

2007) After the outliers were discarded, the average and standard deviation of each data set were

calculated A completely randomized one-way ANOVA and pairwise Sheffe tests were conducted to

determine if the Bluetooth signal strength (distance to alarm) was equal in all directions (sides) from the NXT

The range and reliability of the proximity alarm were then determined in a suburban environment (residential property) with typical signal interferences (Wi-Fi and physical obstacles) The i-gotU was placed in the middle of the back seat of a GMC Envoy with tinted windows The distance to alarm was measured forty times as the NXT was moved from the car to the

front door of the house Figure 3 contains the suburban house test site diagram The Interquartile Range (IQR) was used to identify outliers in each data set (Donnelly, 2007) After the outliers were discarded, the average and standard deviation of each data set were

calculated It is important to note that the GPS data in the house scenario corresponded to only

one location, the location of the i-gotU in the backseat of the car This data was used to analyze the variability of the GPS data and calculate distances for

comparison to the measured Bluetooth signal based distances

THE PROGRAM FLOW CHART

Reset NXT Bluetooth to Factory Settings

Turn on NXT Bluetooth

Configure NXT Bluetooth to Tone with Connect/Disconnect, use Default Password, and Set the Security PIN to 0000

Search for Bluetooth Devices

Connect to i-gotU Bluetooth

Check Bluetooth Connection Between Devices

Bluetooth Signal

Received (In Range)

Yes

No

Start

Increment Count

Display “In Range”, Count, and Position

Display Last GPS Position, Time, and “Out of Range”

Beep Twice

TESTING SITES OVERVIEW

SOCCER FIELD TESTING SITE

TESTING OCCURRED ALONG THE WHITE LINE. THE NXT WAS STATIONARY ON A POST AND THE I-GOTU WAS MOVED ALONG THE WHITE LINE.

HOUSE TESTING SITE

TESTING OCCURRED ALONG THE PATH TO THE FRONT DOOR OF THE HOUSE. THE I-GOTU (SHOWN) WAS LEFT IN THE CAR AND THE NXT WAS MOVED AWAY.

RESULTS: DATA EXAMPLE & SUMMARY TABLE

Data Table 1. Distance to Signal Loss in the Top DirectionLatitude Longitude

Trail # Distance Degrees Minutes Direction Degrees Minutes Direction Time Date

1 5 28 9.526 N 80 35.883 W 14:48:51 13-Mar

2 4 28 9.522 N 80 35.883 W 14:49:50 13-Mar

3 4 28 9.520 N 80 35.884 W 14:51:08 13-Mar

4 5 28 9.519 N 80 35.883 W 14:51:56 13-Mar

5 7 28 9.522 N 80 35.882 W 14:53:16 13-Mar

6 5 28 9.522 N 80 35.883 W 15:29:18 13-Mar

7 5 28 9.521 N 80 35.883 W 15:30:40 13-Mar

8 5 28 9.521 N 80 35.884 W 15:31:31 13-Mar

9 5 28 9.520 N 80 35.884 W 15:32:19 13-Mar

10 7 28 9.521 N 80 35.884 W 15:33:13 13-Mar

11 7 28 9.520 N 80 35.883 W 15:34:53 13-Mar

12 6 28 9.520 N 80 35.884 W 15:35:54 13-Mar

13 9 28 9.520 N 80 35.884 W 15:36:55 13-Mar

14 6 28 9.522 N 80 35.884 W 15:38:03 13-Mar

15 6 28 9.521 N 80 35.885 W 15:39:01 13-Mar

16 6 28 9.523 N 80 35.884 W 15:39:59 13-Mar

17 6 28 9.521 N 80 35.885 W 15:40:56 13-Mar

18 7 28 9.522 N 80 35.884 W 15:41:57 13-Mar

19 8 28 9.527 N 80 35.883 W 15:43:07 13-Mar

20 8 28 9.521 N 80 35.883 W 15:44:05 13-Mar

21 7 28 9.523 N 80 35.884 W 15:45:05 13-Mar

22 4 28 9.523 N 80 35.882 W 15:46:06 13-Mar

23 6 28 9.521 N 80 35.882 W 15:47:00 13-Mar

24 6 28 9.522 N 80 35.882 W 15:47:54 13-Mar

25 6 28 9.522 N 80 35.885 W 15:48:46 13-Mar

26 7 28 9.523 N 80 35.886 W 15:49:49 13-Mar

27 6 28 9.523 N 80 35.885 W 15:50:56 13-Mar

28 7 28 9.521 N 80 35.884 W 15:51:57 13-Mar

29 6 28 9.522 N 80 35.884 W 15:52:49 13-Mar

30 6 28 9.524 N 80 35.888 W 15:54:43 13-Mar

31 7 28 9.522 N 80 35.883 W 15:55:37 13-Mar

32 7 28 9.522 N 80 35.883 W 15:56:45 13-Mar

33 6 28 9.522 N 80 35.884 W 15:57:46 13-Mar

Ave. 6 9.522 35.884

St. Dev. 1 0.002 0.001

Data Table 7. Distance to Signal Loss Summary Table

Trail # Front Left BottomCalculated Distances Right House

1 5 19 52 18.6 37 5.82 4 21 52 48.3 38 5.83 4 39 52 37.4 36 5.54 5 41 52 22.2 37 5.55 7 35 53 27.8 38 5.36 5 32 55 13.1 24 5.57 5 31 54 18.5 40 5.38 5 32 51 20.4 39 5.39 5 32 54 22.2 40 6.0

10 7 33 53 26 40 5.511 7 34 56 16.8 36 5.512 6 37 55 27.9 30 5.313 9 44 55 22.2 40 5.314 6 35 56 31.6 40 5.315 6 37 56 22.2 28 5.316 6 37 55 22.3 31 5.517 6 47 57 24.1 32 5.318 7 32 54 29.8 37 5.019 8 34 54 29.7 35 5.320 8 38 54 44.6 40 5.321 7 37 53 31.5 38 5.522 4 36 52 31.5 38 5.323 6 48 52 31.5 38 5.024 6 33 49 24.1 37 5.825 6 30 52 27.8 35 5.826 7 37 50 22.2 40 5.327 6 20 49 22.2 36 6.028 7 37 54 51.9 37 5.029 6 38 52 22.2 40 5.830 6 44 49 27.8 47 5.531 7 41 53 25.9 23 5.832 7 44 53 42.7 49 6.033 6 24 53 20.6 52 6.034 44 57 40.5 5.535 40 53 35.2 5.836 5.337 5.538 5.239 5.540 5.8

Ave. 6 36 53 28 37 5St. Dev. 1.199691 7.005242 2.096876 9 5.904364 0.285771

RESULTS: STATISTICS – CALCULATED BY HAND BY RESEARCHER

Table 8. Measured Field and House Data Outlier Test

Calculating the Interquartral Range (IQR)

Field Data House

  Top Left Bottom Right  Q1 6 30.5 52 31.5 5.3Q3 7.5 38.5 54.5 40 5.8

   

IQR 1.5 8 2.5 8.5 0.5

   

Outlier Range          

> 9.75 50.5 58.25 52.75 6.55

< 3.75 18.5 48.25 18.75 4.55

   

Number of Outliers in

Data7 5 5 8 0

Data Table 9. ANOVA: Single Factor Test

Summary

Groups Count Sum Average VarianceHypothesi

s

Front 33 205 6.22 1.43926 HO: μ1 = μ2 = μ3 = μ4

Left 35 1245 35.57 49.0734 H1 : not all μ's equal

Bottom 35 1859 53.12 4.39689

Right 33 1228 37.20 34.8615

Total 136 4537 33.36  

ANOVA

Source of Variation SS df MS F P-value F crit α = 0.01

Between Groups 38639.8 3 12879.93331 570.594 2.34E-75 3.9335

Within Groups 2979.62 132 22.57284196

Total 41619.4 135        

Reject HO

Data Table 10. Scheffe Test

Sample Pair FS FSC Conclusion

Top and Left 648.143 11.8005 Difference

Top and Bottom 1655.51 11.8005 Difference

Top and Right 701.878 11.8005 Difference

Left and Bottom 238.961 11.8005 Difference

Left and Right 2.01956 11.8005 No Difference

Bottom and Right 190.667 11.8005 Difference

RESULTS: GRAPHS

GPS DATAPlease note that the time, date, degrees, and direction were taken off in order to fit this summary table on this slide.

Direction and degrees remained constant (28 degrees N lat.; 80 degrees W longitude).

Data Table 11. GPS Distance Summary TableBottom Direction Data 0 Point

Trail # Distance Latitude Longitude Latitude Longitude1 52 9.531 35.882 9.521 35.8832 52 9.547 35.881 9.521 35.8833 52 9.541 35.886 9.521 35.8814 52 9.533 35.883 9.521 35.8835 53 9.536 35.883 9.522 35.8836 55 9.528 35.884 9.522 35.8837 54 9.531 35.883 9.522 35.8838 51 9.532 35.883 9.522 35.8829 54 9.533 35.883 9.520 35.883

10 53 9.535 35.882 9.520 35.88311 56 9.530 35.882 9.521 35.88312 55 9.536 35.882 9.521 35.88313 55 9.533 35.883 9.521 35.88314 56 9.538 35.882 9.521 35.88315 56 9.533 35.883 9.520 35.88216 55 9.533 35.882 9.521 35.88317 57 9.534 35.883 9.521 35.88318 54 9.537 35.881 9.521 35.88319 54 9.537 35.882 9.521 35.88320 54 9.545 35.881 9.520 35.88321 53 9.538 35.883 9.520 35.88422 52 9.538 35.883 9.521 35.88323 52 9.538 35.883 9.521 35.88324 49 9.534 35.883 9.521 35.88425 52 9.536 35.883 9.523 35.88326 50 9.533 35.883 9.521 35.88427 49 9.533 35.883 9.522 35.88328 54 9.549 35.883 9.522 35.88429 52 9.533 35.883 9.521 35.88430 49 9.536 35.883 9.521 35.88331 53 9.535 35.883 9.521 35.88432 53 9.544 35.884 9.521 35.88433 53 9.532 35.885 9.521 35.88334 57 9.523 35.884 9.522 35.88435 53 9.540 35.883 9.521 35.88336       9.519 35.88337       9.520 35.88338       9.521 35.88339       9.520 35.88340       9.521 35.883

         Ave. 53 9.536 35.883 9.521 35.883

St. Dev. 2 0.005 0.001 0.001 0.001

DISCUSSION Field Data

The field data represented a case of minimum signal attenuation from interferences (physical and wireless) The Bluetooth antenna in the NXT was directional (See Graph 1 and 2)

Distance to signal loss from each of the four sides of the NXT varied depending on which side of the NXT was facing the i-gotU

The results of the Completely Randomized One-Way ANOVA analysis confirmed that there was a statistical difference between the all the distances

The Scheffe tests determined that all the sides were statistically different from the each other except in the left and right directions

House Data The house data (home driveway to front door) represented a case with typical signal interferences (Wi-Fi and physical

obstacles)

It was found that the alarm would go off at the protected, recessed area around the front door (See Graph 3) This was significantly less than the corresponding bottom side distance to signal loss observed in the field tests

The 90% signal range loss between the open field and suburban house tests of the NXT/i-gotU alarm system was primarily due to attenuation from physical obstacles

The metal car body, tinted windows and vegetation (due to water content) have significant attenuation values and all contributed to the signal loss

Alarm Design and Operation Evaluation The NXT/i-gotU alarm system worked 200 out of 200 trials showing it was 100% dependable Significant alarm distance variability was noted in consecutive trials (See Graphs 1 and 2)

Alarm distance variability was also noted in commercial units Changing the RobotC program to alarm based on GPS calculated distances rather than Bluetooth signal

loss would not improve alarm distance variability (See GPS Data Slide) The GPS data exhibited significant variability and did not correlate well with the measured signal distances

Several types of proximity alarms were found on the internet (See Table 1) The NXT/i-gotU system was reliable and demonstrated comparable range, but it was larger, heavier, consumed

more power, and was more expensive than the commercial devices Due to these factors, it probably would not be as convenient to use as the other systems However, the NXT/i-gotU system did not have to be purchased and the components can be used for other

purposes

Name Mobility Basis Power Range Comments Price

Ear SystemDefined base area;

Base unit is stationary, tag is attached and tracked

Alarms when tagged item or person goes outside set limits;

Automatic notification to designated phone

Not Specified Up to 1 mile

Range is settable; Originally developed for the U.S. Navy and Coast Guard, currenty used to monitor impaired individuals; Can be used as

proximity alarm and to locate an individual or item within a mile radius

Not listed

Loc8tor LiteHandset with homing tags (2); Handset credit

card size (0.17 oz/ 5g)

Homing tags are attached to items; Automatic notification to designated phone

Handset uses two AA batteries - included Tags use two LR54 batteries - not

included

Up to 122 meters (400

feet)

Stated purpose to locate lost items rather than to notify that item is out of range of device, but might

be able to be used as proximity alarm - unclear$79.99

RFID Tag Alarm

Small mobile monitor (1.75" x 0.1") can clip to belt, key ring or pocket;

Small tag that adheres to valuable item

Tags are attached to items; Small monitor alarm when tag goes

out of range

States 6 mo. Battery Life; Monitor uses two

CR2032 - not included; Tag uses one CR2032 battery - not

included

Two range settings; Short range:

30 ft; Long range:

100 ft

Stated purpose is to secure items within your comfort zone to prevent theft

$39.95 - 59.95

Child Proximity Alarm

Small transmitter device (1.75" H, 1.5" L, 3/16" W) attached to item being protected;

Small receiver (2.5" H, 1.75" L, 3/16" W)Transmitter on item to be protected

Includes two CR2032 batteries

15 to 25 feet   Discontinued

Child GuardTransmitter disguised as a panda bracelet with Velcro strap; Small receiver has a key ring clip

Panda bracelet is attached to item/child; Receiver alarms when item is out of

range

Battery included - no specifications

Settable from 3 to 21 feet

Sensor range is inconsistent; Off switch can easily be bumped into off position -

gives same triple beep as when the device is out of range

$25 - $30

New Child Guard

Transmitter disguised as a blue dog - can be worn as a necklace, bracelet or tag;

Small receiver equipped with key ring clips

Blue dog is attached to item/child; Receiver alarms when

item is out of range

Li Battery included - no specifications

Dial from 6 to 30 feet

Unclear if this is an upgrade of the previous Child Guard or just new packaging

$29 - $40

Anti-theft & Anti-loss Wireless Security

Luggage Alarm (TRA-237)

Small transmitter and receiver equipped with key ring clips; Transmitter 60 x 35 x 20 mm (LWH);

Receiver 50 x 32 x 19 mm (LWH)

3 modes of operation; Anti-loss mode - receiver beeps when transmitter is 3-5 m away, owner then

pushes an alarm button on receiver and transmitter will emit a loud alarm

Transmitter uses two CR2032 batteries - not

included; Receiver uses one CR2032 battery - not

included

Anti-loss range is 3-5 m;

Remote control range

Made to prevent theft of items such as luggage, purses, laptops, etc.

$20.99

Secu4 Blue Watchdog

Credit card sized alarm device paired with a cell phone

Watchdog emits a shrill alarm when separated from the cell phone

Stand-by time of 120 hours; 3.7 v LiPo battery;

Can be charged via recharger or USB

1-30 m configurable

alarm

Sells from the company's website along with a list of compatible phones

$95.00

NXT/i-gotUi-gotU is 46 x 41.5 x 14 mm (LWH) and 37 g; NXT is 11.1 x 7.2 x 4.7 cm

(LWH)

i-gotU is attached to item by strap; NXT is carried by person and alarms when item is out

range

NXT can use 6 AA or a rechargeable battery pack with wall charger;

i-gotU equipped with internal

rechargeable battery with USB charger cable

Open field range of up to

Devices must be turned on and communications established prior to use - usually takes a minute or

two

if purchased separately,

approximately $240

TABLES: MARKET COMPARISON

TABLES: EXAMPLES OF ATTENUATION VALUES OF COMMON CONSTRUCTION MATERIALS

MaterialAttenuation Value

(dBm) ReferenceNotes

Plasterboard wall 3 (Geier, Beating Signal Loss in WLANs)  

Glass wall with metal frame 6 (Geier, Beating Signal Loss in WLANs)  

Cinder block wall 4 (Geier, Beating Signal Loss in WLANs)  

Office window 3 (Geier, Beating Signal Loss in WLANs)  

Metal door 6 (Geier, Beating Signal Loss in WLANs)  

Metal door in brick wall 12.4 (Geier, Beating Signal Loss in WLANs)  

Non-tinted glass 4-5 (Ogunjemilua, Davies and Grout) At 2.4 GHz

Wood door 4-5 (Ogunjemilua, Davies and Grout) At 2.4 GHzCinder block wall 4-5 (Ogunjemilua, Davies and Grout) At 2.4 GHz

Plaster wall 4-5 (Ogunjemilua, Davies and Grout) At 2.4 GHz

Brick wall 5-8 (Ogunjemilua, Davies and Grout) At 2.4 GHz

Marble 5-8 (Ogunjemilua, Davies and Grout) At 2.4 GHz

Wire mesh 5-8 (Ogunjemilua, Davies and Grout) At 2.4 GHz

Metal tinted glass 5-8 (Ogunjemilua, Davies and Grout) At 2.4 GHz

Concrete wall 10-15 (Ogunjemilua, Davies and Grout) At 2.4 GHz

Paper 10-15 (Ogunjemilua, Davies and Grout) At 2.4 GHz

Ceramic bullet-proof glass 10-15 (Ogunjemilua, Davies and Grout) At 2.4 GHz

Metals >15 (Ogunjemilua, Davies and Grout) At 2.4 GHz

Silvering (mirrors) >15 (Ogunjemilua, Davies and Grout) At 2.4 GHz

CONCLUSIONS

This project focused on creating a proximity alarm out of items found around the house that could warn the user if a heat sensitive object or child was left in a car

The NXT-igotU alarm system met the design criteria However, market research showed that while the system performed

comparably to commercially available systems, it was not as convenient or cost effective

The following is a summary of the project conclusions: The RobotC program was 100% reliable. The NXT/i-gotU proximity alarm successfully

alarmed in 200 out of 200 trails. The first hypothesis was supported. The field test results showed that the NXT’s Bluetooth was directional. The second

hypothesis was not supported. The alarm distances based on GPS data exhibited greater variability than the alarm

distances based on Bluetooth signal loss. Alarm variability would not be reduced by changing the RobotC program to alarm based on GPS calculated distances rather than Bluetooth signal loss. The third hypothesis was not supported.

In the suburban test, the NXT/i-gotU’s average signal range was 5.5m. The 90% loss in signal range compared to the field test (53m) was primarily due to physical obstacles.

Significant alarm distance (Bluetooth signal) variability was observed in both the field and suburban test data. Significant variability was also noted in commercial units.

Commercially available alarms were smaller, lighter, consumed less power and were cheaper than the NXT/i-gotU system. However, the NXT/i-gotU demonstrated comparable performance and its components can be used for other activities.

Future Studies The next phase of this project would be to create a proximity alarm out of a cell phone

and an i-gotU GPSThis would improve the convenience of the proximity alarm and possibly reduce the range variability as well due to the higher end electronic components in the phone. Using a phone could even increase the versatility of the system. A GPS equipped phone could be programmed to show the last known location of the i-gotU on a map and the phone’s current location.

BIBLIOGRAPHY & ACKNOWLEDGEMENTS I would like to thank my teachers for all their guidance and encouragement, and my parents for driving me and my equipment back and forth to the soccer fields. I couldn’t have done this project without them.

I would like to thank Wayne Van Sickle for his help and guidance with RobotC.

(2007). Patent No. 7259671.

About ROBOTC. (2009). Retrieved December 7, 2010, from ROBOTC: http://www.robotc.net/download/

Anderson, C. (2007, November 12). The Best Programming Language for Lego Mindstorms, Hands Down. Retrieved December 7, 2010, from WIRED: http://www.wired.com/geekdad/2007/11/the-best-progra

B&H. (n.d.). Loc8tor Lite. Retrieved January 12, 2011, from B&H: http://www.bhphotovideo.com/bnh/controller/home?O=&sku=747391&Q=&is=REG&A=details

Baker, S. M. (2009, April 22). BLuetooth Technology Gets Faster with Bluetooth 3.0. Retrieved December 21, 2010, from Bluetooth: http://www.bluetooth.com/English/Press/Pages/PressReleasesDetail.aspx?ID=16

Bernstein, D. (n.d.). Bluetooth (IEEE 802.15.1): An Introduction. Retrieved December 2010, from James Madison University: https://users.cs.jmu.edu/bernstdh/web/common/lectures/slides_bluetooth.php

Bluetooth and WLAN. (n.d.). Retrieved November 27, 2010, from Eurescom: http://www.eurescom.de/~pub-deliverables/p1100-series/p1118/d3/bltandwlan.html

Bluetooth. (2010). Basics. Retrieved November 27, 2010, from Bluetooth: http://www.bluetooth.com/English/Technology/Pages/Basics.aspx

Bluetooth Low Energy Technology. (2010). Retrieved December 21, 2010, from Bluetooth: http://www.bluetooth.com/English/Products/Pages/low_energy.aspx

Bluetooth Low Energy Technology FAQ. (2009, December). Retrieved December 21, 2010, from Bluetooth: http://www.bluetooth.com/SiteCollectionDocuments/Low_Energy_FAQ_External_General_Public.pdf

Bluetooth SIG. (2010). About the Bluetooth SIG. Retrieved December 2010, from Bluetooth: http://bluetooth.com/English/SIG/pages/default.aspx

Bluetooth SIG Opens Qualification Program for Bluetooth Core Specifications Version 4.0. (2010, July 6). Retrieved December 21, 2010, from Bluetooth: http://www.bluetooth.com/english/press/pages/pressreleasesdetail.aspx?id=106

Bluetooth Wireless Networking Explained. (2010, May 15). Retrieved November 21, 2010, from TheTravelInsider: http://thetravelinsider.info/roadwarriorcontent/bluetooth.htm

Bourk, T. (n.d.). Preventing Bluetooth Interference. Retrieved November 27, 2010, from Cellular Online: http://www.cellular.co.za/technologies/bluetooth/bluetooth_preventing_interference.htm

C Plus Plus. (2009). Retrieved September 4, 2010, from http://www.cplusplus.com

C++ Reference. (n.d.). Retrieved 2010, from cplusplus.com: http://www.cplusplus.com/reference/

Child Guard Proximity Alarm. (n.d.). Retrieved January 6, 2011, from Brick House Security: http://www.brickhousesecurity.com/cguard24.html

Child Proximity Alarm. (n.d.). Retrieved January 6, 2011, from Defense Devices.com: http://defensedevices.com/child-safety-proximity-alarm.html

Chronister, V. (2010, November 28). (S. Van Sickle, Interviewer)

Coulton, P., & Edwards, R. (2007). S60 Programming: A Tutorial Guide. Chichester: J. Wiley & Sons.

Debugging on the Device Quick Start. (2010, September 17). Retrieved 2010, from Symbian Developer: http://developer.symbian.org/wiki/Debugging_on_the_Device_Quick_Start

DePriest, D. (n.d.). NMEA data. Retrieved November 28, 2010, from gpsinformation.org: http://gpsinformation.org/dale/nmea.htm

(2007). In R. A. Donnelly, The Complete Idiot's Guide to Statistics (2 ed., pp. 73-75, 182-183, 289-301). New York City, New York: Alpha.

Edwards, L., & Barker, R. (2004). Developing Series 60 Applications: A Guide for Symbian OS C++ Developers (Advanced Edition ed.). Boston, MA: Addison-Wesley.

Flatley, J. L. (2010, September 28). Blue Watchdog Bluetooth proximity alarm: 100 decibels of aural terror in a credit card-sized package. Retrieved November 27, 2010, from engadget: http://www.engadget.com/2010/09/28/blue-watchdog-bluetooth-proximity-alarm-100-decibels-of-aural-t/

Forum.Nokia. (2010, October 26). Nokia E63. Retrieved August 29, 2010, from Forum.Nokia: http://www.forum.nokia.com/Devices/Device_specifications/E63/

Franklin, C., & Layton, J. (n.d.). How Bluetooth Works. Retrieved November 27, 2010, from howstuffworks: http://electronics.howstuffworks.com/bluetooth.htm

Geier, J. (2002, July 23). Beating Signal Loss in WLANs. Retrieved January 1, 2010, from Wi-Fi Planet Tutorials: http://www.wi-fiplanet.com/tutorials/articles.php/1431101

Geier, J. (2002, July 2). Minimizing Bluetooth Interference. Retrieved September 2010, from Wi-Fi Planet: http://www.wi-fiplanet.com/tutorials/article.php/1379911/Minimizing-Bluetooth-Interference.htm

Golmie, N., & Chevrollier, N. (n.d.). Techniques to Improve Blueooth Performance in Interference Environments. Retrieved November 21, 2010, from National Institute of Standards and Technology: http://www.antd.nist.gov/pubs/golmiemilcom.pdf

Gordon, J. (n.d.). How Do Bluetooth Devices Work? Retrieved October 2, 2010, from eHow: http://www.ehow.com/how-does_4925086_bluetooth-devices-work.html

GPS In More Detail. (n.d.). Retrieved January 12, 2011, from Smithsonian National Air and Space Museum: http://nasm.si.edu/gps/spheres.html

History of Bluetooth Technology. (2010). Retrieved December 2010, from Bluetooth: http://bluetooth.com/English/SIG/Pages/History_of_the_SIG.aspx

BIBLIOGRAPHY & ACKNOWLEDGEMENTSHow Bluetooth Works. (n.d.). Retrieved November 27, 2010, from GSMFavorites.com: http://gsmfavorites.com/documents/bluetooth/works/

How Bluetooth Works - Signal Strength, Frequency, and Profiles. (n.d.). Retrieved November 21, 2010, from BlueTomorrow.com: http://www.bluetomorrow.com/about-bluetooth-technology/how-bluetooth-works/how-bluetooth-works-2.html

How Does GPS Work? (n.d.). Retrieved January 12, 2011, from Smithsonian National Air and Space Museum: http://nasm.si.edu/gps/work.html

How does wireless communication work? (2008, June 10). Retrieved November 28, 2010, from Energi: http://www.savingtrust.dk/consumer/products/energy-saving-equipment/wireless-equipment/how-does-wireless-communication-work

IEEE 802.15 WPAN Task Group 1 (TG1). (2004, Febuary 9). Retrieved December 2010, from IEEE 802.15: http://www.ieee802.org/15/pub/TG1.html

IEEE 802.15 WPAN Task Group 2 (TG2). (2004, May 12). Retrieved December 21, 2010, from IEEE 802.15: http://www.ieee802.org/15/pub/TG2.html

IEEE 802.15 WPAN Task Group 3 (TG3). (2009, June 9). Retrieved December 21, 2010, from IEEE 802.15: http://www.ieee802.org/15/pub/TG3.html

IEEE 802.15 WPAN Task Group 4 (TG4). (2010, January 27). Retrieved December 21, 2010, from IEEE 802.15: http://www.ieee802.org/15/pub/TG4.html

i-gotU Bluetooth GPS Travel & Sports Logger - GT-200e. (2009). Retrieved December 21, 2010, from Mobile Action: http://global.mobileaction.com/product/product_i-gotU_BT.jsp

Kernigham, B. W., & Ritchie, D. M. (1978). The C Programming Language (2 ed.). Englewood Cliffs, New Jersey: Prentice-Hall.

Könsgen, A. (2009). Bluetooth (IEEE 802.15.1). Retrieved December 2010, from Universität Bremen: Communication Networks: http://www.comnets.uni-bremen.de/typo3site/uploads/media/nswlan_ch07_0910.pdf

Lego Mindstorms Team. NXT Technology. In Lego Mindstorms User Guide (p. 11).

Light in the box. (n.d.). Anit-theft & Anti-loss Wireless Security Luggage Alarm (TRA-237). Retrieved 17 2011, January, from Light in the box.com: http://www.lightinthebox.com/Anti-theft---Anti-loss-Wireless-Security-Luggage-Alarm--TRA-237-_p97663.html

Liu, J. (2010, June 15). Review: Child Guard Proximity Alarm. Retrieved January 6, 2011, from Wired: http://www.wired.com/geekdad/2010/06/review-child-guard-proximity-alarm/

Liu, S. (n.d.). Bluetooth Technology. Retrieved November 27, 2010, from Progtutorials: http://progtutorials.tripod.com/Bluetooth_Technology.htm

Martin, J. A. (2002, September 5). Mobile Computing Tips: Bluetooth vs. Wi-Fi FAQ. Retrieved October 2010, from PCWorld: http://www.pcworld.com/article/103848/mobile_computing_tips_bluetooth_vs_wifi_faq.html Mathew, A., Chandrababu, N., Elleithy, K., & Rizvi, S. (2010). Interference of 802.11b WLAN and Bluetooth: Analysis and Performance Evaluation. International journal of Computer Networks & Communications , 2, 11.

Nokia. (n.d.). Symbian SDKs. Retrieved September 5, 2010, from Forum.Nokia: http://www.forum.nokia.com/Library/Tools_and_downloads/Other/Symbian_SDKs/

Null, J. (2010, October 3). Hyperthermia Deaths of Children in Vehicles. Retrieved December 5, 2010, from Golden Gate Weather Services: http://ggweather.com/heat/

Ogunjemilua, K., Davies, J. N., Grout, V., & Picking, R. (2009). An investigation into signal strength of 802.11n WLAN. Glyndwr University, University of Wales, Centre for Applied Internet Research (CAIR), Wrexham, UK.

Pacchiano, R. V. (2004, March 26). Bluetooth vs. Wi-Fi Technology. Retrieved 2010, from Small Buisness Computing.com: http://www.smallbusinesscomputing.com/webmaster/article.php/3331421/Bluetooth-vs-Wi-Fi-Technology.htm

Press & Analysists. (2010). Retrieved December 2010, from Bluetooth: http://bluetooth.com/English/Press/Pages/default.aspx

PROXIMITY ALARMS. (n.d.). Retrieved January 6, 2011, from Community Emergency Alert Response Services: http://www.communityears.com/proximity_alarms.htm

Proximity Sensors. (2009). Retrieved November 22, 2010, from Fargo Controls: http://www.fargocontrols.com/sensors.html

RFID Tag Alarm System. (n.d.). Retrieved January 6, 2011, from Defence Devices.com: http://www.defensedevices.com/rfid-tag-alarm-system.html

S60 Platform SDKs for Symbian OS, for C++. (2006, October 11). Retrieved August 31, 2010, from Forum.Nokia: http://www.forum.nokia.com/info/sw.nokia.com/id/4a7149a5-95a5-4726-913a-3c6f21eb65a5/S60-SDK-0616-3.0-mr.html

Society for Science & the Public. (2010). Rules & Guidelines. Retrieved November 28, 2010, from http://www.societyforscience.org/page.aspx?pid=312

Stichbury, J. (2005). Symbian OS Explained: Effective C++ Programming for Smartphones. West Sussex, England: J. Wiley & Sons.

The Associated Press. (2010, June 25). Deaths of Children in Hot Cars Hit Grim Record. Retrieved 2010, from CBS News: http://www.cbsnews.com/stories/2010/06/25/health/main6617376.shtml

Veness, C. (2010, January). Calculate distance, bearing and more between Latitude/Longitude points. Retrieved January 8, 2011, from Moveable Type Scripts: http://www.moveable-type.co.uk/scripts/latlong.html

Weed, G. (n.d.). How Does Bluetooth Work? Retrieved October 2, 2010, from eHow: http://www.ehow.com/how-does_4564367_bluetooth-work.html

Wi-Fi™ and Bluetooth™ - Interference Issues. (2002, January). Retrieved 2010, from hp: http://www.hp.com/rnd/library/pdf/WiFi_Bluetooth_coexistance.pdf

Woodford, C. (2009, March 24). Bluetooth. Retrieved 2010, from Explain That Stuff!: http://www.explainthatstuff.com/howbluetoothworks.html