Creating an Effective Proximity Alarm Using Household Items

1
Creating an Effective Proximity Alarm Using
Household Items

• By Sarah V.

2
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

3
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.

4
Basic Background Information

• Bluetooth
• Short range wireless communication technology
• Known for its 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

5
The Concept
Devices in Range No Alarm
Devices Not in Range Alarm
6
The Concept cont.
7
Materials Methods

• Materials
• 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 lost
• Methods
• 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

8
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

9
The Program Flow Chart
10
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.
11
Results Data Example Summary Table
Data Table 7. Distance to Signal Loss Summary Table Data Table 7. Distance to Signal Loss Summary Table Data Table 7. Distance to Signal Loss Summary Table Data Table 7. Distance to Signal Loss Summary Table Data Table 7. Distance to Signal Loss Summary Table Data Table 7. Distance to Signal Loss Summary Table Data Table 7. Distance to Signal Loss Summary Table

Trail Front Left Bottom Calculated Distances Right House
1 5 19 52 18.6 37 5.8
2 4 21 52 48.3 38 5.8
3 4 39 52 37.4 36 5.5
4 5 41 52 22.2 37 5.5
5 7 35 53 27.8 38 5.3
6 5 32 55 13.1 24 5.5
7 5 31 54 18.5 40 5.3
8 5 32 51 20.4 39 5.3
9 5 32 54 22.2 40 6.0
10 7 33 53 26 40 5.5
11 7 34 56 16.8 36 5.5
12 6 37 55 27.9 30 5.3
13 9 44 55 22.2 40 5.3
14 6 35 56 31.6 40 5.3
15 6 37 56 22.2 28 5.3
16 6 37 55 22.3 31 5.5
17 6 47 57 24.1 32 5.3
18 7 32 54 29.8 37 5.0
19 8 34 54 29.7 35 5.3
20 8 38 54 44.6 40 5.3
21 7 37 53 31.5 38 5.5
22 4 36 52 31.5 38 5.3
23 6 48 52 31.5 38 5.0
24 6 33 49 24.1 37 5.8
25 6 30 52 27.8 35 5.8
26 7 37 50 22.2 40 5.3
27 6 20 49 22.2 36 6.0
28 7 37 54 51.9 37 5.0
29 6 38 52 22.2 40 5.8
30 6 44 49 27.8 47 5.5
31 7 41 53 25.9 23 5.8
32 7 44 53 42.7 49 6.0
33 6 24 53 20.6 52 6.0
34 44 57 40.5 5.5
35 40 53 35.2 5.8
36 5.3
37 5.5
38 5.2
39 5.5
40 5.8

Ave. 6 36 53 28 37 5
St. Dev. 1.199691 7.005242 2.096876 9 5.904364 0.285771
Data Table 1. Distance to Signal Loss in the Top Direction Data Table 1. Distance to Signal Loss in the Top Direction Data Table 1. Distance to Signal Loss in the Top Direction Data Table 1. Distance to Signal Loss in the Top Direction Data Table 1. Distance to Signal Loss in the Top Direction Data Table 1. Distance to Signal Loss in the Top Direction Data Table 1. Distance to Signal Loss in the Top Direction Data Table 1. Distance to Signal Loss in the Top Direction Data Table 1. Distance to Signal Loss in the Top Direction Data Table 1. Distance to Signal Loss in the Top Direction
Latitude Latitude Latitude Longitude Longitude Longitude
Trail Distance Degrees Minutes Direction Degrees Minutes Direction Time Date
1 5 28 9.526 N 80 35.883 W 144851 13-Mar
2 4 28 9.522 N 80 35.883 W 144950 13-Mar
3 4 28 9.520 N 80 35.884 W 145108 13-Mar
4 5 28 9.519 N 80 35.883 W 145156 13-Mar
5 7 28 9.522 N 80 35.882 W 145316 13-Mar
6 5 28 9.522 N 80 35.883 W 152918 13-Mar
7 5 28 9.521 N 80 35.883 W 153040 13-Mar
8 5 28 9.521 N 80 35.884 W 153131 13-Mar
9 5 28 9.520 N 80 35.884 W 153219 13-Mar
10 7 28 9.521 N 80 35.884 W 153313 13-Mar
11 7 28 9.520 N 80 35.883 W 153453 13-Mar
12 6 28 9.520 N 80 35.884 W 153554 13-Mar
13 9 28 9.520 N 80 35.884 W 153655 13-Mar
14 6 28 9.522 N 80 35.884 W 153803 13-Mar
15 6 28 9.521 N 80 35.885 W 153901 13-Mar
16 6 28 9.523 N 80 35.884 W 153959 13-Mar
17 6 28 9.521 N 80 35.885 W 154056 13-Mar
18 7 28 9.522 N 80 35.884 W 154157 13-Mar
19 8 28 9.527 N 80 35.883 W 154307 13-Mar
20 8 28 9.521 N 80 35.883 W 154405 13-Mar
21 7 28 9.523 N 80 35.884 W 154505 13-Mar
22 4 28 9.523 N 80 35.882 W 154606 13-Mar
23 6 28 9.521 N 80 35.882 W 154700 13-Mar
24 6 28 9.522 N 80 35.882 W 154754 13-Mar
25 6 28 9.522 N 80 35.885 W 154846 13-Mar
26 7 28 9.523 N 80 35.886 W 154949 13-Mar
27 6 28 9.523 N 80 35.885 W 155056 13-Mar
28 7 28 9.521 N 80 35.884 W 155157 13-Mar
29 6 28 9.522 N 80 35.884 W 155249 13-Mar
30 6 28 9.524 N 80 35.888 W 155443 13-Mar
31 7 28 9.522 N 80 35.883 W 155537 13-Mar
32 7 28 9.522 N 80 35.883 W 155645 13-Mar
33 6 28 9.522 N 80 35.884 W 155746 13-Mar

Ave. 6 9.522 35.884
St. Dev. 1 0.002 0.001
12
Results Statistics Calculated by Hand by
Researcher
Data Table 9. ANOVA Single Factor Test Data Table 9. ANOVA Single Factor Test Data Table 9. ANOVA Single Factor Test Data Table 9. ANOVA Single Factor Test Data Table 9. ANOVA Single Factor Test Data Table 9. ANOVA Single Factor Test Data Table 9. ANOVA Single Factor Test

Summary
Groups Count Sum Average Variance Hypothesis
Front 33 205 6.22 1.43926 HO µ1 µ2 µ3 µ4 HO µ1 µ2 µ3 µ4 HO µ1 µ2 µ3 µ4
Left 35 1245 35.57 49.0734 H1 not all µ's equal H1 not all µ's equal 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 a 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 Data Table 10. Scheffe Test Data Table 10. Scheffe Test 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

Table 8. Measured Field and House Data Outlier Test Table 8. Measured Field and House Data Outlier Test Table 8. Measured Field and House Data Outlier Test Table 8. Measured Field and House Data Outlier Test Table 8. Measured Field and House Data Outlier Test Table 8. Measured Field and House Data Outlier Test Table 8. Measured Field and House Data Outlier Test Table 8. Measured Field and House Data Outlier Test

Calculating the Interquartral Range (IQR) Calculating the Interquartral Range (IQR) Calculating the Interquartral Range (IQR) Calculating the Interquartral Range (IQR) Calculating the Interquartral Range (IQR) Calculating the Interquartral Range (IQR)

Field Data Field Data Field Data Field Data House
  Top Left Bottom Right  
Q1 6 30.5 52 31.5 5.3
Q3 7.5 38.5 54.5 40 5.8
   
IQR 1.5 8 2.5 8.5 0.5
   
Outlier Range          
gt 9.75 50.5 58.25 52.75 6.55
lt 3.75 18.5 48.25 18.75 4.55
   
Number of Outliers in Data 7 5 5 8 0
13
Results Graphs
14
GPS Data
Data Table 11. GPS Distance Summary Table Data Table 11. GPS Distance Summary Table Data Table 11. GPS Distance Summary Table Data Table 11. GPS Distance Summary Table Data Table 11. GPS Distance Summary Table Data Table 11. GPS Distance Summary Table
Bottom Direction Data Bottom Direction Data Bottom Direction Data 0 Point 0 Point
Trail Distance Latitude Longitude Latitude Longitude
1 52 9.531 35.882 9.521 35.883
2 52 9.547 35.881 9.521 35.883
3 52 9.541 35.886 9.521 35.881
4 52 9.533 35.883 9.521 35.883
5 53 9.536 35.883 9.522 35.883
6 55 9.528 35.884 9.522 35.883
7 54 9.531 35.883 9.522 35.883
8 51 9.532 35.883 9.522 35.882
9 54 9.533 35.883 9.520 35.883
10 53 9.535 35.882 9.520 35.883
11 56 9.530 35.882 9.521 35.883
12 55 9.536 35.882 9.521 35.883
13 55 9.533 35.883 9.521 35.883
14 56 9.538 35.882 9.521 35.883
15 56 9.533 35.883 9.520 35.882
16 55 9.533 35.882 9.521 35.883
17 57 9.534 35.883 9.521 35.883
18 54 9.537 35.881 9.521 35.883
19 54 9.537 35.882 9.521 35.883
20 54 9.545 35.881 9.520 35.883
21 53 9.538 35.883 9.520 35.884
22 52 9.538 35.883 9.521 35.883
23 52 9.538 35.883 9.521 35.883
24 49 9.534 35.883 9.521 35.884
25 52 9.536 35.883 9.523 35.883
26 50 9.533 35.883 9.521 35.884
27 49 9.533 35.883 9.522 35.883
28 54 9.549 35.883 9.522 35.884
29 52 9.533 35.883 9.521 35.884
30 49 9.536 35.883 9.521 35.883
31 53 9.535 35.883 9.521 35.884
32 53 9.544 35.884 9.521 35.884
33 53 9.532 35.885 9.521 35.883
34 57 9.523 35.884 9.522 35.884
35 53 9.540 35.883 9.521 35.883
36       9.519 35.883
37       9.520 35.883
38       9.521 35.883
39       9.520 35.883
40       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
Please 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).
15
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)

16
Tables Market Comparison
Name Mobility Basis Power Range Comments Price
Ear System Defined 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 Lite Handset 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 Guard Transmitter 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-gotU i-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
17
Tables Examples of Attenuation Values of Common
Construction Materials
Material Attenuation Value (dBm) Reference Notes
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 GHz
Cinder 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 gt15 (Ogunjemilua, Davies and Grout) At 2.4 GHz
Silvering (mirrors) gt15 (Ogunjemilua, Davies and Grout) At 2.4 GHz
18
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 NXTs
  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-gotUs 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 phones current location.

19
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• I would like to thank Wayne Van Sickle for
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