Conor D. Kerslake Capstone Design Final Report

EE 495
Final Report
Target Tracking
Michael Holzer
Conor D. Kerslake
Mike Richards
Advisor: Chandler Janzen

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Michael Holzer, Conor Kerslake, Mike Richards
269 – 815 Kristjanson Rd.
Saskatoon SK S7S 1M6
April 13, 2015
Mr. Chandler Janzen
2C56 Engineering Building
57 Campus Drive, Saskatoon, SK
Saskatoon SK S7N 5A9
RE: Submission of EE 495 Final Design Report
Mr. Janzen,
We are pleased to be submitting to you our final design report for the Target Tracking project.
The report has been prepared in accordance with the specifications of the Electrical Engineering
495 Design Course. This report will provide an in-depth analysis of how the final design was
selected, built, and verified.
The final product that has been designed was supervised by a professional engineer. However,
any work using or expanding on this project requires a professional engineer to verify the
results. This project has been designed and built as a working proof of concept design that is
specifically intended for use by hobbyists. Any other use for this product is outside the intended
scope. This project is not allowed to be developed for commercial use unless otherwise stated
by the undersigned.
Sincerely,
Michael Holzer Conor Kerslake Mike Richards

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Abstract
The customer requires a target tracking system for implementation on their quad-rotor
helicopter. They require a product that can track a target’s relative position in 3-dimensional
space with respect to a receiver located at a base station and control filming equipment that
follows the target.
The desired operation is as follows:
1 The base station will be set up by the customer. This will include some form of computer, a
receiver, some servos, and some controls for the servos. The base station will be attached
to the customer’s quad-rotor helicopter.
2 The target, or object that requires tracking, will enable the transmitter. The target will then
move and operate as desired by the customer.
3 The base station will receive information regarding the target’s position via a signal sent
from the transmitter to the receiver. This information will be displayed on a visual display.
4 The data from the base station will be used as an input to the control system for the servos,
allowing filming equipment to be mounted on the servos and follow the target.
5 The data from the base station will be used as an input to the quad-rotor helicopter’s
autopilot which will enable the helicopter to move to follow the target.
Based on the customer’s requirements, a solution using GPS was developed. This design uses
the Global Positioning Satellite (GPS) Network to determine the global latitude and longitude,
and thus the location, of both the target and the base station. From there, a distance and
orientation can be determined, thus facilitating target tracking. The design was built as a proof-
of-concept with a full-scale implementation in mind in the future.
Each functional block of the system was conceptualized, designed, built and tested thoroughly
to ensure they worked properly and that the overall system worked as desired by the customer.
Some issues that arose during testing were addressed, and some affect the design moving
forward.
The largest problem was the accuracy of the GPS system. The GPS units used provide an
accurate location between 2-4m on average. Since the customer desires an operation range of
5-200m this error is too large. In the future, incorporating a Kalman Filter that uses internal
sensors such as gyroscopes, accelerometers, and magnetometers to supplement the GPS data
and greatly improve the accuracy of the system. Since the system only needs to know relative
distance between the Target and the Base Station the Kalman Filter will provide a much more
accurate and smooth location measurement. The Kalman Filter implementation is necessary for
scaling this design up to be used on a quad-rotor helicopter.

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Table of Contents
Abstract........................................................................................................................................................ iii
Table of Contents......................................................................................................................................... iv
1 Statement of Work.....................................................................................................................................9
1.1 The Problem........................................................................................................................................9
1.2 Desired Function.................................................................................................................................9
1.3 Inputs and Outputs .............................................................................................................................9
1.4 Design Requirements........................................................................................................................10
1.5 Manufactured Cost ...........................................................................................................................10
2 Requirement Specification.......................................................................................................................10
2.1 The Problem......................................................................................................................................10
2.2 Specification of Reliability and Maintainability ................................................................................11
2.3 Testing...............................................................................................................................................11
2.4 Criteria for Manufactured Cost.........................................................................................................11
3 Design Alternatives ..................................................................................................................................12
3.1 Evaluation Metrics ............................................................................................................................12
3.2 Design Alternative 1 – Infrared Sensing............................................................................................13
3.2.1 Reliability Evaluation..................................................................................................................13
3.2.2 Implementation Evaluation .......................................................................................................13
3.2.3 Cost Evaluation ..........................................................................................................................13
3.2.4 Safety Evaluation........................................................................................................................13
3.3 Design Alternative 2 – Global Positioning Satellites .........................................................................13
3.3.3 Cost Evaluation ..........................................................................................................................14
3.4 Design Alternative 3 – “Marco Polo”................................................................................................14
3.4.3 Cost Evaluation ..........................................................................................................................15

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3.5 Design Alternative Choice.................................................................................................................15
4 System Block Diagram..............................................................................................................................16
4.1 Overall System Block Diagram ..........................................................................................................16
4.2 Target Communication Block............................................................................................................16
4.2.1 Description.................................................................................................................................16
4.2.2 Inputs and Outputs ....................................................................................................................17
4.2.3 Operation...................................................................................................................................17
4.3 Base Station Communication Block ..................................................................................................18
4.3.1 Description.................................................................................................................................18
4.3.3 Operation...................................................................................................................................18
4.4 Base Station Block.............................................................................................................................18
4.4.1 Description.................................................................................................................................18
4.4.3 Operation...................................................................................................................................19
4.5 Control Block.....................................................................................................................................19
4.5.1 Description.................................................................................................................................19
4.5.3 Operation...................................................................................................................................20
4.6 Actuator Block...................................................................................................................................20
4.6.1 Description.................................................................................................................................20
4.6.3 Operation...................................................................................................................................21
4.7 Power Block.......................................................................................................................................21
4.7.1 Description.................................................................................................................................21
4.7.3 Operation...................................................................................................................................21
5 Design Implementation and Testing........................................................................................................22
5.1.1 Implementation .........................................................................................................................22
5.1.2 Testing........................................................................................................................................23

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5.2.1 Implementation .........................................................................................................................23
5.2.2 Testing........................................................................................................................................24
5.3.1 Implementation .........................................................................................................................24
5.3.2 Testing........................................................................................................................................25
5.4 Control Block.....................................................................................................................................25
5.4.1 Implementation .........................................................................................................................25
5.4.2 Testing........................................................................................................................................26
5.5 Actuator Block...................................................................................................................................26
5.5.1 Implementation .........................................................................................................................26
5.5.2 Testing........................................................................................................................................26
5.6 Power Block.......................................................................................................................................26
5.6.1 Implementation .........................................................................................................................26
5.6.2 Testing........................................................................................................................................26
6 Project Plan..............................................................................................................................................27
6.1 Project Phases...................................................................................................................................27
6.1.1 Meetings ....................................................................................................................................27
6.1.2 Documentation ..........................................................................................................................27
6.1.3 Project Design ............................................................................................................................29
6.1.4 Building and Testing...................................................................................................................31
6.1.5 Presentation and Report............................................................................................................32
6.2 Project Milestones ............................................................................................................................33
6.3 Cost Projections ................................................................................................................................33
6.4 Timeline of Tasks...............................................................................................................................34
7 Bottom Block Design................................................................................................................................34
8 Final Design..............................................................................................................................................35
9 Testing and Verification ...........................................................................................................................36
9.1.1 Overview....................................................................................................................................36
9.1.2 Tests...........................................................................................................................................36
9.1.3 Results........................................................................................................................................37

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9.2.1 Overview....................................................................................................................................37
9.2.2 Tests...........................................................................................................................................37
9.2.3 Results........................................................................................................................................37
9.3.1 Overview....................................................................................................................................37
9.3.2 Tests...........................................................................................................................................38
9.3.3 Results........................................................................................................................................39
9.4 Control Block.....................................................................................................................................39
9.4.1 Overview....................................................................................................................................39
9.4.2 Tests...........................................................................................................................................40
9.4.3 Results........................................................................................................................................40
9.5 Actuator Block...................................................................................................................................41
9.5.1 Overview....................................................................................................................................41
9.5.2 Tests...........................................................................................................................................41
9.5.3 Results........................................................................................................................................41
10 Project Plan Analysis..............................................................................................................................42
10.1 Time Resources Spent on Prototype...............................................................................................42
10.2 Monetary Resources Spent on Prototype.......................................................................................43
11 Recommendations for Future Work......................................................................................................43
12 Resources...............................................................................................................................................44
13 Works Cited............................................................................................................................................45
Appendix A – Bottom Block Schematics .....................................................................................................46
Base Station Schematic...........................................................................................................................46
Base Station Shield Schematic ................................................................................................................47
Target Block Schematic...........................................................................................................................48
Appendix B – Code Flow Charts..................................................................................................................49
Control Block Code..................................................................................................................................49
Base Station Block Code..........................................................................................................................50
Base Station Communication Block Code...............................................................................................51
Appendix C – Project Plan Gantt Chart.......................................................................................................52
Appendix D – User’s Manual.......................................................................................................................53
1.0 General Information .............................................................................................................................53

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1.1 System Overview...............................................................................................................................53
1.2 User Manual Overview......................................................................................................................53
2.0 Summary of the 3DPT ...........................................................................................................................53
2.1 System Requirements.......................................................................................................................53
2.2 System Constraints ...........................................................................................................................53
2.3 Troubleshooting the Device..............................................................................................................54
3.0 Getting Started......................................................................................................................................54
3.1 Description of Parts...........................................................................................................................54
....................................................................................................................................................................56
4.0 Operating the Device ............................................................................................................................56
4.1 Turning the Device On or Off............................................................................................................56
Appendix E – Latitude/Longitude to Northing/Easting Calculation............................................................57
Figure 1 - Design Alternative Evaluation.....................................................................................................15
Figure 2 - Design Alternative Evaluation Totals..........................................................................................15
Figure 3 - Overall System Block Diagram ....................................................................................................16
Figure 4 - Target Communication Block......................................................................................................17
Figure 5 - Base Station Communication Block............................................................................................18
Figure 6 - Base Station Block.......................................................................................................................19
Figure 7 - Control Block...............................................................................................................................20
Figure 8 - Actuator Block.............................................................................................................................21
Figure 9 - Power Block ................................................................................................................................21
Figure 10 – Adafruit Ultimate GPS Breakout ..............................................................................................22
Figure 11 - XBee Pro Module ......................................................................................................................22
Figure 12 - TI Stellaris Launchpad ...............................................................................................................24
Figure 13 - Servo .........................................................................................................................................26
Figure 14 - Final Design Hardware..............................................................................................................35
Figure 15 – Final Design Hardware .............................................................................................................35
Figure 16 - Pulse Width Modulation Verification .......................................................................................40
Figure 17 - Pulse Width Modulation Verification .......................................................................................40
Table 1 - Planned Cost Breakdown .............................................................................................................34
Table 2 - Pulse Width Modulation Test Results..........................................................................................41
Table 3- Servo Test Results .........................................................................................................................41
Table 4 - Time Spent on Project..................................................................................................................42
Table 5 - Money Spent on Project...............................................................................................................43

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1 Statement of Work
This section of the report outlines the initial conversations with the customer in order to
determine their requirements, constraints, and parameters for a successful design.
1.1 The Problem
The customer requires a target tracking system for implementation on their quad-rotor
helicopter. They require a product that can track a target’s relative position in 3-dimensional
space with respect to a receiver located at a base station and control filming equipment that
follows the target.
1.2 Desired Function
The desired operation is as follows:
1 The base station will be set up by the customer. This will include some form of computer, a
receiver, some servos, and some controls for the servos. The base station will be attached
to the customer’s quad-rotor helicopter.
2 The target, or object that requires tracking, will enable the transmitter. The target will then
move and operate as desired by the customer.
3 The base station will receive information regarding the target’s position via a signal sent
from the transmitter to the receiver. This information will be displayed on a visual display.
4 The data from the base station will be used as an input to the control system for the servos,
allowing filming equipment to be mounted on the servos and follow the target.
5 The data from the base station will be used as an input to the quad-rotor helicopter’s
autopilot which will enable the helicopter to move to follow the target.
The customer has requested the transmitter, base station receiver, servo controls, and servos
operating together as described above as deliverables for this design. A computer and visual
display will be used or developed to assist in the testing and evaluation process.
Implementation on a quad-rotor helicopter is not required for this design. However, in order for
the design to satisfy the customer’s requirements, this proof-of-concept design must
demonstrate the ability to be implemented as described above. This includes proper
considerations for size, weight, operating environments, and safety.
1.3 Inputs and Outputs
This system is to be mostly self-contained. The system is to operate on battery power, so no
power input is required. The customer desires a hands-off system, which means minimal set-up
and user input.

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The placement of the base station sets the reference for the target’s relative position. Thus, the
only input of the system is the customer’s placement of the base station.
Based on the inputs, the product will have two outputs. The first is the target’s position relative
to the base station which will be shown on the visual display. The second output is the position
of the servos which orient the filming equipment towards the target.
1.4 Design Requirements
1) Physical Properties
a) The system that attaches to the target must not exceed:
 Height: 125mm
 Width: 60mm
 Depth: 20mmaad
2) Operational Requirements
a) The design must be able to wirelessly track the target in all three (3) axes with less than
2% error with respect to the distance between the target and base station
b) The design must be able to wirelessly orient filming equipment in all three (3) axes
c) The system that attaches to the target must operate for a minimum of eight (8) hours
without re-charging
3) Operational Constraints
a) The design must operate within a range of five (5) meters to two-hundred (200) meters
4) Operating Environment
a) The design must operate in temperatures ranging from -40o
C to +80o
C
1.5 Manufactured Cost
The customer requires the entire system have a Manufacturer’s Suggested Retail Price (MSRP)
of less than $100.
2 Requirement Specification
This section of the report contains background market research to gain some insight into the
customer’s requests outlined in Section 1 of this report as well as their quantification in order
to establish measurable metrics for the success of the design.
2.1 The Problem
Extreme sports are popular in the world today and people thrive on sharing their successes
through social media. Capturing these extreme sports on film has created success for
businesses like GoPro. However, there are limitations to current technology. It is difficult to get
high quality video if the camera is sitting on a helmet or if a camera is on a following vehicle due

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to the lack of a method of stabilization and independent movement. For example, when
professional bikers film their off-road runs, they will attach a camera to their helmet or to a
following bicycle. As the run progresses, the camera is subject to all of the movement
experienced by the bike and must be aimed manually, resulting in a shaky video. The customer
wants a device that can be mounted and follow a target independently. The device should be
able to orient itself to the biker as the course is traversed, allowing for smooth video capture.
2.2 Specification of Reliability and Maintainability
The product must be reliable so that it can perform in a predictable manner when used in larger
systems. This is a problem when larger systems are much more expensive than the design.
Since the design is used in the control of the customer’s quad-rotor helicopter, it must be
reliable so as to not cause a crash.
The maintainability of the system will be limited to linking the target to the base station,
keeping the device clean and providing reliable power to the product through the replacement
and/or charging of batteries. No internal components in the device should need to be changed
or maintained under normal circumstances. Replacement parts will be limited to the main PCB
board fully populated, plastic housing, connecting wires and receiving antenna.
2.3 Testing
A test-driven design process will be used for this design. Each functional block of the design will
be designed and tested independently of all others. The interfaces between each block will be
well-defined and testable. Once a block is tested, and its inputs and outputs deemed working
acceptably, the blocks will be assembled and tested as a whole.
Each block will have testing pins that the testing apparatus will connect to and run various tests
to ensure the product is working as intended.
Due to the specialized nature of this design, various testing apparatus’ will be developed to test
each block as well as the entire system.
2.4 Criteria for Manufactured Cost
The cost to manufacture this product should be no more than $30. That way we can account for
the labor costs and still make a profit. The materials involved should not be expensive, but
there will be parts that are more expensive simply because of the specific requirements (i.e.
operating temperature) that the devices must adhere to.

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3 Design Alternatives
In this section of the report, alternative solutions to the customer’s problem (as outlined in
Sections 1 and 2 of this report) are conceptualized, evaluated, and ranked in order to determine
the optimal solution to the problem.
The focus of the design is target tracking. Thus, the only design alternatives being considered
are those which pertain for finding the target’s location and tracking it. Once this is obtained,
the rest of the design (camera orientation, power, etc.) will be built based on it.
3.1 Evaluation Metrics
Before the design alternatives are discussed, the criterion which will be used to evaluate the
possible designs will be introduced. Each design alternative is ranked based on five metrics:
1) Reliability
2) Implementation
3) Cost
4) Safety
The reliability metric was established based on conversations with the customer. The customer
is looking for a product that they can use multiple times without significant wear. Also, this
system is to be made to interface with a quad-rotor helicopter. Thus, any failure of this system
could cause a crash or collision of the helicopter. Therefore, reliability is a key aspect of
choosing a design alternative. A design alternative scores high in the reliability metric if it is
deemed to have a high degree of reliability.
The implementation metric was established based on the nature of the design project. The
customer requires an actual working system. Therefore, it is not acceptable to waste the
customer’s time and money with a system that may not be able to be constructed due to costs,
development time, or unreliable methods. A design alternative scores high in the
implementation metric if it is deemed to be easy to build.
The cost metric was established based on conversations with the customer. The customer
requires a low-cost system, not only for their personal use, but also so that this design can be
marketed in the future. A design alternative scores high in the cost metric if it is deemed to cost
a low amount.
The safety metric is inherent to any design which is used in the public sector. Since this design
will be attached to something that flies, it is especially important that the design is safe to both
use and be in the vicinity of. A design alternative scores high in the safety metric if it is deemed
to be safe to operate and be around while it is operating.

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3.2 Design Alternative 1 – Infrared Sensing
The first design alternative being considered uses infrared (IR) sensing to find the target. An IR
source is placed on the target and emits radiation. This radiation is sensed by an IR sensor
located on the base station, and a direction is obtained based on the incident light’s direction.
3.2.1 Reliability Evaluation
One of the biggest problems with using an IR based system is the Sun. The sun emits a high
amount of IR radiation which causes a lot of interference for IR sensors. Also, the IR sensor
relies heavily on line-of-sight. This raises some concerns with this design alternative in terms of
reliability. One possible solution is to limit the use of the design to night-only, but this simply
isn’t feasible based on the customer’s desired use of the product.
3.2.2 Implementation Evaluation
This design alternative would be very difficult to implement. Not including finding or building an
IR source that could compete with the Sun in terms of intensity, building an IR sensor capable of
picking up the radiation from any direction would be extremely complicated.
3.2.3 Cost Evaluation
Because this alternative consists of an array of IR sensors and a single IR source, this design
alternative was deemed to be fairly cheap to construct.
3.2.4 Safety Evaluation
Because this system was deemed to be unreliable due to interference from the Sun, and from
its reliability on line-of-sight, this design alternative would not be safe for the operator to use or
people to be around because the signal could be lost at any given moment.
3.3 Design Alternative 2 – Global Positioning Satellites
The second design alternative being considered uses the Global Positioning Satellite (GPS)
Network to determine the global latitude and longitude, and thus the location, of both the
target and the base station. From there, a distance and orientation can be determined, thus
facilitating target tracking.
This design alternative relies heavily on existing systems, mainly the GPS Network. Devices
which integrate with this network need to be purchased, and this lends a degree of reliability to
this alternative, assuming these devices operate as intended.

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The purchased GPS modules do a lot of the back end work for this design alternative. Once the
devices are determined to be working properly, it becomes a case of properly utilizing the
outputs of the system. This, coupled with the reliability assessment already discussed, greatly
adds to the ease of implementation for this design alternative.
As discussed earlier, the GPS modules would need to be purchased for this design alternative.
These modules are generally expensive, thus driving up the cost of the prototype and the
design alternative as a whole.
The fact that this design relies on the existing GPS Network, and the modules for interfacing
with this network need to be purchased, a lot of safety considerations have already been made.
As long as the system developed around the GPS modules is safe, the design alternative overall
will be considered very safe.
3.4 Design Alternative 3 – “Marco Polo”
This design alternative consists of a signal generator and an array of antennas. The signal
generator sends out a dummy signal tone at a specified frequency and specified interval. The
signal is received by several of the antennas. Based on which antennas receive the signal at
which time, the orientation of the target with respect to the base station will be able to be
determined, and the time between the sending and receiving of the signal will give the distance
between the target and the base station.
If implemented properly, this design alternative would be reliable. The system which tracks the
target doesn’t involve complicated signals, and it would be difficult to misinterpret the
information.
This design alternative is incredibly complex and thus would be difficult to implement properly.
It would require a lot of testing which may not be feasible for the time frame the customer has
given.

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Due to the complexity of this design alternative, it would end up being very expensive. All of the
antenna used to make up the triangulation would have to be designed and custom built, and
antennas are difficult to manufacture.
The communication range this design alternative uses is well established and noise free, meaning there
would be very little interference with its correct operation. Also, depending on the frequency range
used, the system would be able to get around line-of-sight issues that the other design alternatives
struggled with.
3.5 Design Alternative Choice
Each design alternative, as
discussed earlier in Section 3,
was evaluated based on the
evaluation metrics discussed
in Section 3.1. The
alternatives were assigned a
score out of ten in each of
these metrics. The results of
this evaluation can be seen in
Figure 1.
The total score overall for
each design alternative was
then used to determine which
alternative would be the most effective in solving the customer’s problem. These totals can be
seen in Figure 2.
Based on the evaluation, the
GPS alternative was chosen as
the best design alternative.
Figure 1 - Design Alternative Evaluation
2
0
8
1
8
8
4
8
8
2
2
8
0 2 4 6 8 10
Reliability
Implementation
Cost
Safety
Marco Polo
GPS
IR
Figure 2 - Design Alternative Evaluation Totals
0
5
10
15
20
25
30
IR GPS Marco Polo
Total
IR
GPS
Marco Polo

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4 System Block Diagram
In this section of the report, a high level block diagram of the system is discussed. This creates
the framework for the design, and allows the work to be modularized. An overall block diagram
will be shown, followed by a breakdown of each individual block. This section of the report
emphasizes how the overall system will work and how each block will work together to create
the system.
4.1 Overall System Block Diagram
The block diagram of the system that will meet the functional and specification requirements is
shown in Figure 3.
4.2 Target Communication Block
4.2.1 Description
The Target Communication Block sends a wireless electrical signal to the Base Station
Communication Block over a wireless channel. This signal indicates the current location of the
target. The Target Communication Block consists of four components. The first is the signal
transmitter which is responsible for sending the signal which indicates the target’s current
Figure 3 - Overall System Block Diagram

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position. The second is the power block which supplies portable power to the system (i.e. a
battery). Next is the GPS Block which is responsible for obtaining the target’s location. The final
component is the processing block which is responsible for interfacing between the GPS Block
and the transmitter. The block diagram of the Target Communication Block is shown in Figure 4.
4.2.2 Inputs and Outputs
The Target Communication Block has one input which is the non-electrical signal Target
Position. The target’s location information contained in this signal is what needs to be sent to
the Base Station Communication Block.
The Target Communication Block has a single output signal, which is called the Location Signal.
The signal contains information that describes the target’s current positon.
4.2.3 Operation
The Target Communication Block will be attached to the customer’s desired target.
The Target Communication Block obtains the non-electrical Absolute Target Position signal
from the GPS Block and converts it to an electrical signal called Location Information. The
Location Information signal may
have to be sent through the
processing block if the GPS Block
and transmitter are incompatible.
This intermediate signal is sent to
the Transmitter Block, which
packages the Location Information
signal into the Location Signal which
is sent to the Base Station
Communication Block over the
wireless channel. The Power input
signal, which is obtained from a
portable power supply attached to
the Target Communication Block, powers the GPS Block, Transmitter Block, and Processing
Block.
Figure 4 - Target Communication Block

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4.3 Base Station Communication Block
4.3.1 Description
The Base Station Communication Block receives the signal from the Target Communication
Block over the Wireless Channel and conditions it in such a way as to both retain the
information and ensure it is suitable to be sent to the Base Station Block. The Base Station
Communication Block is shown in Figure 5.
The Base Station Communication Block has two inputs. The first is the Power signal, which is
acquired from the Power Block. The second input is the Location Signal, which is received over
the wireless channel from the Target Communication Block.
The Base Station Communication Block has a single output, which is the Location Information
signal. It is determined by removing the transmission components of the Location Signal so that
only the information contained within is retained.
4.3.3 Operation
The Base Station Communication Block will be attached to the Base Station Block to reduce the
amount of power and space that the system uses
up. Having short communication lines will also
reduce possible error.
The Base Station Communication Block takes the
Location Signal that was sent by the Target
Communication Block over the wireless channel
and reconstructs the Location Information signal in
the Receiver Block. The Power signal, which comes
from the Power Block, powers the Receiver Block.
4.4 Base Station Block
4.4.1 Description
The Base Station Block is the main block of the system. It collects all of the data obtained by the
Base Station Communication Block and performs calculations to transform the data into
relative position information. The Base Station Block then sends this information to the user
and to the Control Block. The Base Station Block also serves as the point of reference to which
the target’s relative position is calculated. The Base Station Block is shown in Figure 6.
Figure 5 - Base Station Communication Block

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The Base Station Block has three inputs. The first is the Power input signal, which is obtained
from the Power Block. Next is the Location Information signal that comes from the Base Station
Communication Block. The final input to the Base Station Block is a non-electrical signal called
the Reference Point that is obtained when the customer sets up the base station.
The Base Station Block has one output that is sent to two locations. The Relative Position signal
is sent to the user and to the Control Block.
4.4.3 Operation
The GPS Block takes the non-electrical Reference signal and creates the Reference Point signal
which represents the Base Station Block’s
location. The Processing Block takes the
Reference Point signal and the Location
Information signal from the Base Station
Communication Block and calculates the
relative position of the target with respect to
the Base Station Block. It then sends a signal,
called the Relative Position signal, to the user
and to the Control Block.
4.5 Control Block
4.5.1 Description
The Control Block is responsible for controlling the Actuator Block. It takes the relative position
signal from the Base Station Block and uses it to derive signals which are then sent to the
Actuator Block. These derived signals will adjust the orientation of the servos within the Servo
Block to follow the target. The Control Block is shown in Figure 7.
The Control Block has four inputs. The first is the Relative Position signal from the Base Station
Block. There are two input signals called the Current Theta and Current Phi signals. These are
feedback signals from the Actuator Block. The final input is the Power input signal that comes
from the Power Block.
Figure 6 - Base Station Block

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The Control Block has two outputs, which are
the Desired Theta Position and the Desired Phi
Position signals. These signals are sent to the
Actuator Block so that it can adjust its
orientation.
4.5.3 Operation
The Control Block takes the Relative Position
signal from the Base Station Block and puts it
through the Theta and Phi Blocks. Each of these
blocks uses the Relative Position signal along
with its respective feedback signal to create its
respective output signal. The output signals
Desired Theta and Desired Phi are sent to the
Actuator Block.
4.6 Actuator Block
4.6.1 Description
The Actuator Block consists of an array of actuators. There are two actuators within the
Actuator Block, each forming a sub-block of the system. The first actuator is able to rotate 360o
and is responsible for rotating about the theta (θ) axis of a Spherical coordinate system. The
second actuator is able to rotate 180o
and is responsible for rotating about the phi (φ) of a
Spherical coordinate system. The Actuator Block is shown in Figure 8.
The Actuator Block has three inputs. The first is the Power input signal. The other two inputs
are the Desired Theta Position and Desired Phi Position signals from the Control Block.
The Actuator Block has two outputs which are the Current Theta Position and Current Phi
Position signals which represent the current orientation of the actuators. These signals are
obtained from potentiometers or encoders attached to the actuators which adjust the voltage
sent back to the Control Block.
Figure 7 - Control Block

21
4.6.3 Operation
The Actuator Block consists of two
blocks which represent physical
actuators, the Theta Actuator and Phi
Actuator Blocks. The Desired Theta
signal goes to the Theta Actuator Block
and is used to adjust the Current Theta
non-electrical output. The Current
Theta signal is converted to an electrical
signal through the use of a
potentiometer or encoder, and is sent
as a feedback signal to the Control
Block. The exact same process is used
for the Phi portion of the block.
4.7 Power Block
4.7.1 Description
The Power Block supplies power to the Base Station Communication Block, Base Station Block,
Control Block, and Actuator Block, as well as each respective block’s sub-blocks. The Power
Block is shown in Figure 9.
The Power Block only has the Power input signal. This will be obtained from a normal wall
outlet.
The Power Block has an output signal for each of the five other blocks. The amount of current
and voltage needed in each signal will be
discussed later in this report.
4.7.3 Operation
The Power Block takes the Power input signal
and creates the Output Power signals which are
suitable for powering each respective block.
Figure 8 - Actuator Block
Figure 9 - Power Block

22
5 Design Implementation and Testing
This section of the report outlines the components that will be selected to implement each
block, as well as the testing plan for each block.
5.1.1 Implementation
The Target Communication Block will be
implemented by choosing components for
each sub-block (as seen in Figure 4).
The GPS Block will be implemented using
the Ultimate Breakout GPS from Adafruit
as seen in Figure 10. This chip will perform
a lot of the back-end work necessary for
this project. It communicates with the
GPS network and sends out a variety of
information including latitude, longitude, altitude, time, landspeed, and much more. This
communication takes place over UART. The Ultimate Breakout GPS only requires power to
work, and the settings can be adjusted from the microprocessor in the base station, therefore
the Processing Block will not be required.
The Transmitter Block will be implemented using an
XBee Pro Module (XBP24-AWI-001) as seen in Figure
10. The range of this module far outstrips that which
is required for this design. This module was chosen
with future projects in mind.
The Power Block will be implemented using a Lithium-
Ferrite (LiFe) battery. This type of battery supplies a
small amount of power for a long period of time, and
they’re also fairly safe to use. Based on the other
components chosen for the Target Communication
Block, the size of the battery should be 5000 mAh.
The Target Communication Block was designed with the design requirements discussed in
Section 1 in mind. The size constraint was considered, and all components chosen will fit in the
125mm by 60 mm by 20mm requirement. The XBee module ensures that the design will meet
the 5 meter to 200 meter operational range requirement. Finally, the appropriately-sized LiFe
Figure 10 – Adafruit Ultimate GPS Breakout
Figure 11 - XBee Pro Module

23
battery will allow the Target Communication Block will be able to operate for eight hours
without charging.
5.1.2 Testing
The first testing that will be performed will be to ensure that the transmitters work as
advertised using the manufacturer’s verification tests. Once the operation of the transmitters is
verified, they will be configured to work as a “long-range wire” (i.e. whatever shows up at the
input gets sent out, and vice versa). With configuration complete, test data will be sent back
and forth to ensure that the configuration was successful, and the operation is correct. Once
the transmitter is working properly, it will be ready for use.
The GPS module will also be verified. Power will be applied and the data will be collected into a
microprocessor and displayed in a Putty terminal to make sure the data is coming through.
Once data is obtained, the GPS modules will be configured as required by the design, and re-
tested to make sure the correct data is being sent. Once this is complete, the GPS module will
be left in an open area to report data for a long period of time in order to verify the reported
accuracy. Once the accuracy of the GPS module has been verified, it will be ready for use.
The voltage of the LiFe battery will be measured over a 1 Ohm resistor to ensure it is supplying
the right amount of power. It will then be tested under sufficient load conditions to verify its
operation for eight hours. This test will be performed multiple times to make sure the battery
operates the same over multiple power cycles.
The Base Station Communication Block will be implemented by choosing components for each
sub-block (as seen in Figure 5).
The Receiver Block will be implemented using an XBee Pro Module (XBP24-AWI-001) as seen in
Figure 11. The range of this module far outstrips that which is required for this design. This
module was chosen with future projects in mind.
The Base Station Communication Block was designed with the design requirements discussed in
Section 1 in mind.. The XBee module ensures that the design will meet the 5 meter to 200
meter operational range requirement.

24
5.2.2 Testing
Testing will be performed will be to ensure that the transmitters work as advertised using the
manufacturer’s verification tests. Once the operation of the transmitters is verified, they will be
configured to work as a “long-range wire” (i.e. whatever shows up at the input gets sent out,
and vice versa). With configuration complete, test data will be sent back and forth to ensure
that the configuration was successful, and the operation is correct. Once the transmitter is
working properly, it will be ready for use.
The Base Station Block will be implemented by choosing components for each sub-block (as
seen in Figure 6).
The GPS Block will be implemented using the Ultimate Breakout GPS from Adafruit as seen in
Figure 10. This chip will perform a lot of the back-end work necessary for this project. It
communicates with the GPS network and sends out
a variety of information including latitude,
longitude, altitude, time, landspeed, and much
more. This communication takes place over UART.
The Ultimate Breakout GPS only requires power to
work, and the settings can be adjusted from the
microprocessor in the base station, therefore the
Processing Block will not be required.
The Processing Block will be implemented using a
Texas Instruments Stellaris LM4F120 LaunchPad
Evaluation Board (EK-LM4F120XL) as seen in Figure
12. This is an easy to use microprocessor that has a
lot of pre-developed resources available for use. It
is well equipped for UART communication which is
what the GPS modules use.
The calculation to find that Target’s relative position works as follows. The Base Station receives
GPS data from the functional blocks described above in the form of latitude and longitude of
both the Target and the Base Station. This data is then compared with a table to find which
Universal Transverse Mercator (UTM) Zone the Target and Base Station are in. The UTM is a
projection of the earth’s spherical surface onto a rectangular grid, and greatly simplifies the
Figure 12 - TI Stellaris Launchpad

25
calculations required to find relative position and orientation. A more in depth look at the
calculations required is given in Appendix E.
The Base Station Block was designed with the design requirements discussed in Section 1 in
mind. The Base Station Block constantly computes the target’s relative position and sends it to
the Control Block. The use of GPS modules allows this relative position to be calculated in all
three dimensions using latitude, longitude, and altitude.
5.3.2 Testing
The GPS module will be verified to be making properly. Power will be applied and the data will
be collected into a microprocessor and displayed in a Putty terminal to make sure the data is
coming through. Once data is obtained, the GPS modules will be configured as required by the
design, and re-tested to make sure the correct data is being sent. Once this is complete, the
GPS module will be left in an open area to report data for a long period of time in order to
verify the reported accuracy. Once the accuracy of the GPS module has been verified, it will be
ready for use.
The Processing Block will be tested to make sure it is operating properly based on the
manufacturer’s instructions. The Processing Block will be running various coded modules to
allow the design to function. These modules include communicating with the GPS modules,
calculating the relative position, and communicating with the other blocks. Each of these coded
modules will be tested and verified in their own right.
5.4 Control Block
The Control Block will be implemented by choosing components for each sub-block (as seen in
Figure 7).
The Control Block is housed entirely within the microprocessor inside the Base Station Block. It
takes the Base Station Block’s calculation of the relative position and creates a Pulse-Width
Modulation (PWM) signal which is used by the servos in the Actuator Block.
The Control Block was designed with the design requirements discussed in Section 1 in mind.
The Control Block outputs two PWM signals that tell the Actuator Block how to orient the
servos. This allows the camera to follow the target in all three dimensions.

26
5.4.2 Testing
The code developed for this block will be tested to ensure that when a position is given to it as
an input, it outputs the correct pulse-width.
5.5 Actuator Block
The Actuator Block will be implemented by choosing components for each sub-block (as seen in
Figure 8).
The Theta and Phi Blocks will each be
implemented by a Servo as seen in Figure
13.
The Control Block was designed with the
design requirements discussed in Section 1
in mind. The combination of the movement
of the two servos allow the camera to be
moved to follow the target in all three
dimensions. The servos have been chosen
to have enough torque to move a 500 gram
camera as specified by the customer.
5.5.2 Testing
Each servo in the Actuator Block will be
tested to make sure they work properly, and that they respond appropriately to PWM signals of
various pulse-widths.
5.6 Power Block
The Power Block will be implemented using a power supply. The Power Conditioning circuits
will be implemented using voltage regulators if requried.
5.6.2 Testing
The outputs of the Power Block will be tested to ensure they are supplying the correct amounts
of power.
Figure 13 - Servo

27
6 Project Plan
This section of the report outlines the plan for completing the design on time and within
budget.
The project has been divided into five main phases: Meetings, Documentation, Project Design,
Building and Testing, and Presentation and Report. Within phase there are specific tasks that
are to be completed within the time frame given. Each specific task will be broken down into
two parts: Deliverables and Resources Required.
6.1 Project Phases
6.1.1 Meetings
This phase was done continuously throught the entire project. We scheduled weekly meetings
throughout the year. These meetings usually ran for approximately 1 hour. Normally we met
with our supervisor but sometimes it is was just our design group that is meeting. At these
meetings we discussed how the project was going, what we needed to do next, and any
problems we were having.
Deliverable: Logbooks are the deliverable for the meeting section. These logbooks keep up to
date information that had been discussed in the meetings. They also serve as a record of each
individual’s work in the project.
Resources Required: The resources for these meetings consisted of logbooks and the entire
group being present. One hour per week was alotted for each meeting. Therefore with three
people in our group we spent a total of three hours per week on meetings.
6.1.2 Documentation
This phase was mostly completed in the first term. It consists of a series of reports written
druring the design process.
Statement of Work
This part of the project was our first piece of documentation and it assisted us in
clarifying what the project entailed. This portion included the problem definition, the
customer’s requirements and constraints, and functionality including inputs and outputs
to the system. We also included some testing plans, manufacturer’s cost and a user’s
manual.
Deliverable: The deliverable was the statement of work that has already been
submitted.

28
Resources Required: This assignment was to be done by all three group members. We
each spent a total amount of 3 hours each which totals to 9 hours total for this piece of
documentation.
Requirement Specification
The requirement specification document took our statement of work and provided a
more in-depth look at our design. We expanded on the problem statement and
definition, narrowed down the exact customer requirements and constraints, and
focused more on the reliability and maintainability of our design. We also added a basic
project plan that included a general outlook of what our milestones are.
Deliverable: The deliverable was the requirement specification document that has
already been submitted.
Resources Required: This assignment was to be done by all three of the group
members. We each spent a total amount of 6 hours on this assignment which totals to
18 hours.
System Block Diagram and Analysis Plan
This assignment was done individually. Each of the three members in the group came
up with how we each thought the block diagram for the design should be represented.
We each explained the functionality of the block, inputs and outputs and then at the
end of the report we provided an analysis plan for the entire block diagram. The
analysis plan was a description of how we would go about testing each block.
Deliverable: The deliverable was the system block diagrams and analysis plans that we
each created individually and have already submitted.
Resources Required: This assignment was to be done individually by each member in
the group. We each had spent approximately 6 hours working on this document. This
totals up to be 18 hours for the group.
System Specification
This document takes what was submitted for the requirement specifications document
and becomes even more detailed. The system specification also includes an overall
block diagram with each block having defined inputs, outputs and functionality. The
document also will show an in-depth analysis of how the blocks will be tested
individually and the document finishes by providing a breakdown about the
maintainability and reliability of each block.

29
Deliverable: The deliverable was the system specification document that will be
submitted with this project plan.
Resources Required: This project was designed for two group members to work on.
This documentation was assigned to Conor Kerslake and Mike Richards who spent
approximately 8 hours each for a total of 16 hours.
Project Plan
The project plan provides a broken down task list that will assist our group in the design
of the 3D position tracking. The plan is to include a brief description of each task and
also include the deliverables and resources required to finish the task. The plan will also
include histograms defining the effort contributed (in cumulative hours) thus far in the
project by each group member, and a cost list that shows the budget for the design.
Deliverable: This document is the project plan that is to be submitted.
Resources Required: This task was designed for one group member to create. It was
assigned to Michael Holzer who spent approximately 8 hours on it.
System Presentation
This presentation was based on the first of two terms of the design. It was presented to
the EE/CME 495 capstone design class. The presentation explains the design project,
what has been accomplished so far, and the alternatives and final solution. The
presentation will also lay out the plan for the rest of the project, costs within the project
and it will give us more practice for when we have to do the final presentation near the
end of term 2.
Deliverable: The presentation for our group took place on Tuesday November 25, 2014.
Resources Required: This presentation is for all group members. It accounts for 6 hours
each totalling 18 hours for the presentation.
6.1.3 Project Design
This portion of the project includes some minor documentation and several major components
of the design. This portion will all be done together as a group.

30
Develop Alternatives
This section we developed three different alternatives to choose the design from. These
alternatives are designs that would be able to meet the requirements and constraints of
the customer.
Deliverable: A minimum of three possible solutions to the customer’s problem that
meet both the requirements and constraints outlined by the customer.
Resources Required: This part of the design requires each person in the group. There
was 8 hours spent each for a total of 24 hours for the group.
Choose Design
This section is where we took a final look at the analyzed data from evaluating the
alternatives and chose our design.
Deliverable: We have chosen the solution for our problem that we will be implementing
and designing a prototype of.
Resources Required: All three members were working for 2 hours for a total of 6 hours
spent on choosing the design.
Create Block Interfaces
In this section we designed all the interfaces within our block diagram. We decided how
we are going to have the blocks communicate with one another and made sure there
was more than one option for each.
Deliverable: We have chosen the interfaces and will be using them to help us in the
design of each individual block of the solution.
Resources Required: All three members spent 8 hours creating the interfaces for a total
of 24 hours.
Design Blocks
We designed each functional block individually before building to make construction of
the system easier in the future. It also allowed us to find any potential bugs or issues
before it was too late to adjust for them.
Deliverable: Each part of the entire block diagram will have been designed completely.

31
Resources Required: Each person will be spending approximately 48 hours designing
the blocks for a total of 144 hours.
Part Orders and Shipping
Parts were ordered in early December so that they arrived before January.
Deliverable: Orders were placed with multiple companies and the components arrived
in time for the construction of the design.
Resources Required: Each person was involved with this step and will spend
approximately 8 hours each for a total of 24 hours.
6.1.4 Building and Testing
This portion of the design was where we spent the majority of our time. This part of the
process is where we implemented and tested our design solution to make a working prototype.
There are four steps in this section. We built the design modularly so we could replace a block
in the block diagram easily if required.
Construct Blocks
This task is broken down into implementing the main blocks in our system block
diagram. Each of the sub-blocks will be assigned within the group for an even amount
of work.
Deliverable: We will have each block built and ready to be tested for the next step.
Resources Required: Each team member will spend approximately 48 hours total
working on the building portion for a total of 144 hours.
Test Blocks
This step is where each constructed block was tested individually.
Deliverable: This portion of the design will have each main block from our block
diagram working on its own.
Resources Required: Each team member will spend approximately 48 hours total
testing their assigned blocks. It is important to note that troubleshooting time has been
included in the time approximately being spent. The total group time spent on this
section is 144 hours.

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Construct Design
This task is where we took all the modular blocks and combined them to build the
prototype. Since the design is modular there should not be a large amount of time
spent on this step.
Deliverable: This portion will provide us with the prototype that still needs to be tested
overall.
Resources Required: Each team member will work together for 8 hours each totalling to
24 hours.
Test Design
This step is where we tested the prototype.
Deliverable: This will provide us with a working prototype of the 3D Position Tracking
System.
Resources Required: Each team member will work together spending approximately 48
hours each on the testing and troubleshooting for a total of 144 hours.
6.1.5 Presentation and Report
This is the final step of the design. After the prototype has been built, we will spend the rest of
the time before the project is due working on the report and final presentation.
Prepare Presentation
This is the final presentation that was made to the instructors, supervisors and other
students in EE/CME 495. This presentation provided the audience with background
information on our objectives for the project and how we went about accomplishing
them. We also presented a working prototype of our solution.
Deliverable: The final presentation was given on March 16th
, 2015.
Resources Required: This portion of the project requires all three members for
approximately 24 hours each totalling to 72 hours.
Final Report
This report will be the final document that we produce for our capstone design class. It
will include all the previous documents and will also give a bit of a reflection on the

33
design from our perspective. It will discuss improvements and changes that we would
like to make if we were to do the process again.
Deliverable: The final report of our EE/CME 495 capstone design project.
Resources Required: This task requires all three members for 13 hours each totalling 39
hours.
Hand-Over to Customer
This is the final step for our design project. This step will include a user’s manual that we
will provide to the customer with the prototype that we have built.
Deliverable: A satisfied customer.
Resources Required: This part of the design requires all three members spending 5
hours, with a total of 15 hours.
6.2 Project Milestones
There are five major milestones that are involved with our project. These phases have also been
divided up into smaller tasks which essentially are milestones on their own. The major
milestones are as follows:
 Documentation Milestone – November 26th, 2014
 Project Design Milestone – January 4th, 2015
 Building and Testing Milestone – February 15th, 2015
 Presentation and Report Milestone – March 27th, 2015
 Project Completion – April 9th, 2015
It will be to our advantage that the actual solution for the design should be working by mid-
February so that we will have extra time to perfect the design before it will be required to
present it.
6.3 Cost Projections
Engineering Costs
This part of the design requires the total number of engineering hours that we will have spent
on the design to calculate the only non-repeating cost of the project. Using an average rate per
hour that engineering students get paid of $20.98 and the total of 346 hours spent each on the
project we can calculate:

34
348 𝐻𝑜𝑢𝑟𝑠
𝑆𝑡𝑢𝑑𝑒𝑛𝑡
× 3 𝑆𝑡𝑢𝑑𝑒𝑛𝑡𝑠 ×
$20.98
𝐻𝑜𝑢𝑟
= $21, 903.12
Parts Costs
Our parts for the prototype were ordered by December 6, 2014. The plan was for these parts
to arrive before January so we can begin the building process. The cost breakdown for the parts
used is shown in Table 1.
Table 1 - Planned Cost Breakdown
Part Number of
Parts
Ordered
From
Unit Price Total
Price
GPS 2 Adafruit Adafruit Ultimate
GPS Breakout
$79.90
Voltage Regulator 4 DigiKey 785-1277-2-ND $0.70 $2.80
Microprocessor 3 DigiKey MK-10-DM-
32VFTS-ND
$3.73 $11.19
Transmitter/Receiver 2 Sparkfun XBP24-AWI-001 $40.00 $80.00
Analog Components $10.00 $10.00
Digital Components $10.00 $10.00
Servo 1 Sparkfun ROB-10189 $11.95 $11.95
Battery 1 Hobby King $4.57 $4.57
Servos 2 $10.00 $20.00
Total $230.41
6.4 Timeline of Tasks
A Gantt Chart outlining the projected timeline of all tasks can be found in Appendix C.
7 Bottom Block Design
Each block in Section 4 was designed further in depth. This includes hardware schematics and
flow charts of all of the executable code. The low level designs and layouts can be found in
Appendix A and the code flow charts can be found in Appendix B.

35
8 Final Design
This section of the report shows the final state of the design.
Figure 14 shows the final design hardware including the Base Station Communication Block,
Base Station Block, Control Block, and Actuator Block. The bottom-right also shows the LCD that
displays information to the user. The large rectangular item in the center is a GoPro camera.
The system is currently mounted on a tripod.
Figure 15 shows the rest of the final design hardware for the Target Communication Block. The
large blue item is the battery that was used for testing and does not represent the battery that
would be implemented in the full design.
Figure 14 - Final Design Hardware
Figure 15 – Final Design Hardware

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9 Testing and Verification
This section of the report outlines the tests that were performed to ensure that individual
blocks and the system were working as intended. Each test will be described, the results will be
discussed, and any changes that needed to be made will be given.
9.1.1 Overview
The Target Communication Block is responsible for collecting data from the GPS module and
transmitting the it to the Base Station Communication Block. The Target Communication Block
is comprised of three components: Power Block, GPS Block and the Transmitter Block.
9.1.2 Tests
In order to ensure the block works as a whole, each module is tested to ensure it is working as
the manufacturer intended or within design parameters.
The Transmitter Block is implemented using an XBee radio. The XBee radios are programmed
using the software provided by the manufacturer. Next, the radio in the Base Station
Communication Block is connected to the software that allows the user to “tap in” to the radio
and verify its operation. The XBee radio in the Target Communication Block has the transmit
and receive (Tx, Rx) pins short circuited together. This short circuit allows for any data sent
from the coordinator to be transmitted back, or echoed, to the coordinator by the other radio.
Data is entered into the coordinator and thedata is echoed back. This received data is
compared to make sure it is the same.
The GPS Block is implemented using an Ultimate GPS Breakout from Adafruit. The GPS module
is tested by connecting TTL cables, which allow a computer program such as PuTTy, to read
UART data. The output data is read into a csv file on a personal computer. The output from the
GPS module is location information in standard National Marine Electrionics Association
(NMEA) format. After a pre-determined time the test is terminated. The output file from the
GPS module is then parsed and location information is extracted. The data is then placed in a
Google Spreadsheet and a Fusion table is used to present the latitude and longitude
information on a Google Map. This allows for visualization of the data and verification that the
GPS module is reporting locations correctly.
The Power Block is implemented using a LiFe Battery and 3.3 Volt Voltage Regulator. The Power
Block is tested by measuring the output voltage from the LiFe Battery given variable input
voltage and ensuring it holds steady at 3.3V.

37
9.1.3 Results
The XBee modules were found to work exactly as the manufacturer intended.
The GPS modules were found to be too inaccurate without any active antenna connected.
Therefore, active antenna were ordered. Once the antenna were attached, the test was
performed again and the GPS modules performed adequately within tolerance (line of sight, ~2
meter error, weather, etc.).
The voltage range supplied by the battery exceeded the specification, and the voltage regulator
kept the level at 3.3 Volts as required.
9.2.1 Overview
The Base Station Communication Block is responsible for receiving the data sent by the Target
Communication Block and relaying it to the Base Station.
9.2.2 Tests
The Base Station Communication Block is implemented using an XBee radio. The testing
procudre is the same as for the Target Communication Block. The XBee radios are programmed
using the software provided by the manufacturer. Next, the radio in the Base Station
Communication Block is connected to the software that allows the user to “tap in” to the radio
and verify its operation. The XBee radio in the Target Communication Block has the transmit
and receive (Tx, Rx) pins short circuited together. This short circuit allows for any data sent
from the coordinator to be transmitted back, or echoed, to the coordinator by the other radio.
Data is entered into the coordinator and thedata is echoed back. This received data is
compared to make sure it is the same.
9.2.3 Results
The XBee modules were found to work exactly as the manufacturer intended.
9.3.1 Overview
The Base Station Block is the control center for the design. It takes in the location information
from its GPS module as well as the Target Communication Block and it provides orientation
output for Servo Control Block.

38
9.3.2 Tests
The Base Station Block has two sub-blocks. The Processing Block is implemented using a Texas
Instruments Stellaris LM4F120 LaunchPad Evaluation Board (EK-LM4F120XL). It has several
functional blocks of code which needed testing.
Multi-Buffer Module: This functional block takes in location data from the GPS modules and
stores it in a multiple-layer buffer so that the Base Station can analyze the inputs in order. This
also forces the Base Station to wait to read an entire NMEA string before trying to extract data.
The multi-buffer is first tested on a personal computer with a surrounding multi-threaded
program providing random delayed inputs. The program has a main loop which continuously
polls the multi-buffer for completed input data and if it receives any it prints the received data
to the screen. The other threads provide input data which is not always complete at random
delayed times. Once the thread completes sending a data package it print out what what was
transmitted and that the thread is preparing to transmit again. The output of the entire
program is analyzed to see if there are any discrepancies between what is sent and what is
received.
Once the multi-buffer works as intended on the personal computer it is transferred to the
microprocessor and the input threads are replaced by the GPS module outputs. The main loop
is the main loop of the microprocessor. When the microprocessor obtains completed GPS input
data it displays it to the LCD testing screen. The output is analyzed to ensure that none of the
data is lost and the data package is complete.
NMEA Parsing Module: This module takes in a NMEA string and determines if it the desired
type of NMEA data and if so extracts the required information..
This module is tested by passing known NMEA strings in and analyzing the output. If the output
is correct for the input then this module is deemed to be working as intended.
Latitude/Longitude to Northing/Easting Conversion: This module takes in latitude and
longitude and converts it to a northing and easting value.
The module is first implemented in MatLab to ensure the underlying math is sound and various
latitudes and longitudes are properly converted to their respective northing/easting values.
Once the module works as intended in MatLab, it is transferred to the microprocessor where
known latitude and longitude values are passed in and the output is analyzed for correctness. If
the output is correct for the testing input it is deemed to be working as intended.

39
Once the above three modules are working, they are incorporated into the Base Station Block
to provide input for further testing. Location data is provided to the BSB and the orientation
output signal is tested to check for errors. By using two different known GPS locations for input
to the Base Station Block, the output values for distance and orientation can be checked for
validity.
The GPS Block is implemented using an Ultimate GPS Breakout from Adafruit. The testing
procedure for this section is the same as for the Target Communication Block. The GPS module
is tested by connecting TTL cables, which allow a computer program such as PuTTy, to read
UART data. The output data is read into a csv file on a personal computer. The output from the
GPS module is location information in standard National Marine Electrionics Association
(NMEA) format. After a pre-determined time the test is terminated. The output file from the
GPS module is then parsed and location information is extracted. The data is then placed in a
Google Spreadsheet and a Fusion table is used to present the latitude and longitude
information on a Google Map. This allows for visualization of the data and verification that the
GPS module is reporting locations correctly.
9.3.3 Results
The multi-buffer worked as intended by only providing complete location data to the Base
Station Block main loop and keeping the input UART buffer as empty as possible.
The Latitude/Longitude to Northing/Easting module worked as intended.
The NMEA parsing module had an issue working on the microprocessor because some C++
libraries do not work as they do on a personal computer. One example is the function that
converts a float string into a double type value. This caused the microprocessor to crash
randomly. Therefore, most C++ libraries that were used had to be re-written. Once this was
completed, the module performed as intended.
The main loop worked as intended but there were many adjustments made to data
transmission intervals to avoid overflowing buffers. Once the adjustments were made the
system performed as intended.
9.4 Control Block
9.4.1 Overview
The Control Block receives orientation information from the Base Station and sends out signals
to control the Actuator Block. The signals it provides are Pulse Width Modulated (PWM) signals
which store the orientation information.

40
9.4.2 Tests
The Control Block output is connected to the digital input on an Analog Discovery Module
Design Kit and the WaveForms program is used to communicate with the design kit. The
program allows the user to view the output waveform in discrete time intervals. The period of
the PWM as well as the on-time is measured using the WaveForms program.
9.4.3 Results
Figure 16 shows that the period is 20ms as specified by the requirements.
Figure 17 shows one of the above on-time sections in an expanded view. The on-time is
consistent with the specifications for 0°.
Table 2 shows the tested on-time values as well as the measured period for various orientation
inputs.
Figure 16 - Pulse Width Modulation Verification
Figure 17 - Pulse Width Modulation Verification

41
Table 2 - Pulse Width Modulation Test Results
Degree
s
Expected On Time
(us)
Actual On Time (us) Error (+/- 3us) Period (ms)
-90 600 600 0 20
-45 1050 1045 5 20
0 1500 1500 0 20
45 1950 1950 0 20
90 2400 2390 10 20
The Control Block was determined to be operating as intended.
9.5 Actuator Block
9.5.1 Overview
The actuator block receives the orientation signal from the SCB and using the signal sets the
servos in the correct position.
9.5.2 Tests
The Actuator Block is implemented using two servos. A servo is connected to the Control Block
with the testing positions similar to those in the Control Block testing section. Since the Control
Block is tested and deemed to be working as intended, this test is able to make use of the block.
The servo output shaft is connected to a marker needle that can be used to read rotation values
from a protractor under it. An orientation input is sent to the Control Block and the rotation
position is read from the output shaft of the servo.
9.5.3 Results
Table 3 shows the results from the test described above. The error is within specified tolerance
so the block works as intended.
Table 3- Servo Test Results
Input (Degrees) Measured Output Angle (+/-
2°)
Error
(degrees)
-80 -80 0
-45 -44 1
0 0 0
45 45 0
80 79 -1

42
10 Project Plan Analysis
This section of the report discusses our actual resources spent during the design process.
10.1 Time Resources Spent on Prototype
The amount of time spent on the project was less than was originally estimated. This was not
to say that the project didn’t require a lot of work, but we were fortunate enough to have
things work in our project sooner than was projected.
The projected time spent on meetings and documentation was accurate with each person
spending 30 and 40 hours respectively.
As for the actual design, it was estimated that each person would spend 82 hours each while
the actual time spent was 42 hours each. The reason for the extra 40 hours estimated is that
we were not sure at the time which alternative would be used for the design. Some of the
alternatives required extra components that would be more work to implement and so we
provided an over-estimate rather than an under-estimate for time spent in this phase.
For the building and testing phase, it was estimated that 154 hours each would be spent and
the actual was 80 hours each. This was due once again to the design alternative selected. Also,
we approached the design modularly, so we allocated some extra time to get the blocks
working together and therefore provided another over-estimate on time spent.
Lastly, in the presentation and report phase it was estimated 42 hours each would be spent and
the actual time spent was 16 hours each. This is due to the significant amount of time spent
previously on documentation. Using the other reports saved a lot of time in this section.
Originally the estimated engineering costs were $21,903.12. By over-estimating the actual time,
the actual engineering costs were much lower than earlier stated. Thus, the customer saved
just short of ten thousand dollars, with the final engineering cost coming in at $13,091.52. This
information is summarized in Table 4.
Table 4 - Time Spent on Project
Phase Estimated Time (per person) Actual Time (per person)
Meetings 30 30
Documentation 40 40
Design 82 42
Building and Testing 154 80
Presentation and Report 42 16
Total 348 208

43
10.2 Monetary Resources Spent on Prototype
The amount of money spent to build the prototype was about forty dollars over the original
estimate. This is due to having to purchase extra parts such as the Sparkfun XBee Explorer to
program our XBee modules, and the active antennas for the GPS modules to improve their
accuracy. We made our own circuit boards to package everything together. Lastly, an LCD
screen was purchased and was used for testing. The XBee Explorer and LCD screen are one-
time purchases. Now that we have the devices available, they will be able to be used in future
designs or prototypes without having to be re-purchased. The overall costs for building the
prototype was $272.93. This is $42.52 more than what the original estimate. This information
is summarized in Table 5.
Table 5 - Money Spent on Project
Part Budgeted
Number
Number
Used
Unit Price Total Price Vendor
GPS Module 2 2 $39.95 $79.90 Adafruit
Voltage Regulator 4 4 $1.95 $3.90 Digi Key
Microprocessor 3 2 $3.73 $7.46 Digi Key
XBee Module 2 2 $40.00 $80.00 Sparkfun
Misc. Analog Components 10 10 $1.00 $10.00
Misc. Digital Components 10 10 $1.00 $10.00
Servo 1 2 $16.10 $32.20 Sparkfun
Battery 1 1 $4.57 $4.57 Hobby King
XBee Explorer 0 1 $24.95 $24.95 Sparkfun
LCD Screen 0 1 $9.95 $9.95 Adafruit
Circuit Boards 0 2 $5.00 $10.00
Estimated Total $230.41
Actual Total $272.93
11 Recommendations for Future Work
This section of the report discusses the current state of the project, as well as outlining future
work that may have to be done to improve the design’s performance.
The project has fulfilled the proof of concept the customer required. The next step in the
project is to further increase the accuracy of the reported position, implement the
communication between the Base Station and the autopilot, and provide a communication port
for data transfer.

44
Links to the videos showing the operation of the device can be found in the Resources section
of this report.
The GPS units used provide an accurate location between 2-4m on average. Since the customer
desires an operation range of 5-200m this error is too large. In the future, incorporating a
Kalman Filter that uses internal sensors such as gyroscopes, accelerometers, and
magnetometers to supplement the GPS data and greatly improve the accuracy of the system.
Since the system only needs to know relative distance between the Target and the Base Station
the Kalman Filter will provide a much more accurate and smooth location measurement.
In order to implement communication between the Base Station and the autopilot, research
will be needed in order to determine what interface is used by the autopilot. A separate
module will then be designed that will interface between the autopilot and the Base Station.
In order to facilitate user exploration into the designed system, a user interface will need to be
designed. The interface will be in the form of UART or SPI Microwire where the user will input a
request string and wait for a response for the requested data.
12 Resources
Adafruit Ultimate GPS Breakout (https://www.adafruit.com/products/746)
XBee Pro Module (https://www.sparkfun.com/products/8742)
Texas Instruments Stellaris LM4F120 LaunchPad Evaluation Board
(http://www.digikey.ca/product-detail/en/EK-LM4F120XL/296-34897-ND/3601071)
Voltage Regulators (https://www.sparkfun.com/products/526)
Servos
(http://www.hobbyking.com/hobbyking/store/__9811__Hitec_HS_485HB_Deluxe_servo_4_8k
g_45g_0_22sec.html?gclid=CjwKEAjw0q2pBRC3jrb24JjE8VgSJAAyIzAdK3aUACMcC31w5l5l0dTu
kw2keG_lLdQEvztetOneKRoC0rfw_wcB)
System Operation Video 1
(https://drive.google.com/file/d/0B2y7Vc2gsmGkWTAtZHRmaDI2clk/view?usp=sharing)
System Operation Video 2
(https://drive.google.com/file/d/0B2y7Vc2gsmGkaE93VW51YnVJUmc/view?usp=sharing)

45
13 Works Cited
Dutch, Steven. Converting UTM to Latitude and Longitude (Or Vice Versa)
(http://www.uwgb.edu/dutchs/UsefulData/UTMFormulas.HTM). Green Bay: University of
Wisconsin - Green Bay, September 12 2003.

46
Appendix A – Bottom Block Schematics
Base Station Schematic

47
Base Station Shield Schematic

49
Appendix B – Code Flow Charts
Control Block Code

51
Base Station Communication Block Code

52
Appendix C – Project Plan Gantt Chart

53
Appendix D – User’s Manual
1.0 General Information
This section will explain the intended use of the prototype that has been built for the
customer.
1.1 System Overview
This system is a proof of concept that has been designed for our customer. The system is able
to track a target in 3-Dimensional Space relative to the base station. The 3DPT (3 Dimensional
Position Tracking) has been designed to be operated outdoors in an open space. The intended
use of the 3DPT prototype is to use the onboard GoPro camera to film the target.
1.2 User Manual Overview
This user manual consists of four sections: General Information, Summary of the 3DPT, Getting
Started, Operating the Device.
General Information is for the customer to have a basic idea of the use of the 3DPT system.
Summary of the 3DPT will go into depth on the constraints of use and what the system will
require to operate properly. It will also include a brief section on troubleshooting.
Getting Started provides the user with the basic parts on the device.
Operating the Device provides the user with detailed descriptions of the system operation.
2.0 Summary of the 3DPT
The system summary provides the user with a brief overview of the system. It will inform the
user of the basic requirements, constraints and some troubleshooting with the device.
2.1 System Requirements
The system requires four double A (AA) batteries to power the servos control block. These
batteries will provide the servos with the proper power to operate and are not included. The
base station system requires a 5 volt (2W) source to operate the base station. To power the
system a conventional cell phone charger rated for 3 to 5 watts will power the system. The
Target device requires 4 to 13 volts to operate and transmit its location.
2.2 System Constraints
This device should not be used indoors due to GPS signals being weak or non-existent. The
3DPT is recommended to be used in large open spaces with some to no tree coverage. The
device should not be used below -10 °C or above 30 °C. No parts should be removed from this
device; otherwise the device will not operate as intended. The device is for use of people 16
years or above.

54
2.3 Troubleshooting the Device
The device should not to be modified in any way. Performance is not guaranteed for any device
that has been modified or damaged by the customer. If problems do arise you can contact one
of the developers of the 3DPT.
1) Green LED not lit when target battery plugged in:
a) Check target battery voltage to ensure it is above the minimum 4V level.
b) Check connection between Target Block and target battery to ensure it is plugged in.
2) LCD screen not backlit when base station plugged into 5V power supply:
a) Ensure power supply is 5V.
b) Ensure power supply can provide at least 3W of power.
c) Ensure good connection between base station and power supply.
3) Base station cannot connect to either LOCAL or REMOTE GPS:
a) Ensure active antenna is plugged into GPS module.
b) Ensure active antenna has good connection to micro SMA connector.
c) Ensure there are not too many obstructions blocking GPS signals.
d) Ensure the troubleshooting points 1 and 2 criteria are met.
4) Camera orientation not pointed at target:
a) Re-zero base station with target.
3.0 Getting Started
This section provides the user with a description of the parts on the device.
3.1 Description of Parts
There are two major components to the entire system. The first component is called the base
station and can be seen in figure 1. The large black box on the top that says GoPro is the GoPro
device. The mechanical system that is holding the camera is the servos and metal structure
that allows to camera to move, up down, left and right is the control system. Near the bottom
right there is a blue LCD screen that is for user information purposes and is backlit once power
is applied to the base station. Slightly above the LCD screen, there is the red breakout (TI
Launchpad) board microcontroller that performs all the computing and calculations for our
device. Directly above the TI Launchpad is the GPS and XBee shield. The black box that is at the
bottom of the image is the battery pack that is used to power the servos.

55
Figure 1: Base Station
Figure 2 is a picture of our target block that the base station will track. This device contains a
large Lithium-Ferrite blue battery. On the right part of the figure the XBee Pro communication
can be seen. To the left of that is the 3.3 voltage regulator. To the left of the voltage regulator
is the GPS module on a blue breakout board.
Figure 2: Target

56
4.0 Operating the Device
This section will provide the user with an in-depth description on how the system will operate.
4.1 Turning the Device On or Off
1. Attach active antenna to the micro SMA connector.
2. Plug in active antennas to both GPS modules.
3. Turn recording device on (GoPro camera).
4. Plug in power to the Target Block. If the green LED light is not lit see troubleshooting
section.
5. Plug in 5V power supply to the base station. If LCD screen is not backlit see
troubleshooting section.
6. Turn on servo power supply switch.
7. Wait for display messages for connecting to LOCAL and REMOTE GPS to finish.
8. Wait 5 minutes for GPS modules to obtain a stable position fix.
9. Once location information is displayed on the LCD screen press Button 1 to zero the
device while the target is at the same location as the base station.
10. The device is now ready to use. If for any reason the tracking becomes unstable simply
re-zero the device.
If the device is to ever be shut off or to end or start recording a new video clip on the GoPro
camera, the user needs to turn the off the power to the servos to prevent damage.
Figure 3 - Micro SMA
Figure 4 - Active Antenna

57
Appendix E – Latitude/Longitude to Northing/Easting Calculation
This calculation was found in (http://www.uwgb.edu/dutchs/UsefulData/UTMFormulas.HTM)

58
Northing and Easting values are found for both the Target and the Base Station. Once these are found,
relative position and orientation are able to be found.

Conor D. Kerslake Capstone Design Final Report

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