Group 8
David Morrow
Ricardo Rodriguez
Shane Theobald
Nick Bauer
University of Central Florida
College of Electrical Engineering and Computer Science
Senior Design Fall 2011

Wanted to gain experience in many different
engineering disciplines
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C# - GUI
Optics – Laser Range Finder
Wireless Communication
Controlling Peripheral Devices via Microcontroller

Calculate the GPS coordinates of a user
specified target using the following
components.
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Wireless Camera
Laser Rangefinder
Digital Compass
GPS Module
Minimize
◦ Cost
◦ Weight
◦ Power Consumption

Target Specs
◦ 5m minimum distance
◦ 100m maximum distance
◦ 10m x 10m minimum target size

Accuracy
◦ Rangefinder distance within ±10m
◦ Self GPS coordinates within 5m radius of true
location
◦ Compass heading within ±1° of true heading
◦ Final target GPS coordinates within 50m radius of
true location

Methods of Laser Rangefinding
◦ Triangulation
 Easiest method both conceptually and design
 Based on geometry
 Increasingly less accurate as range increases
◦ Interferometry
 Most accurate method of laser rangefinding
 Can measure small distances on order of wavelengths
◦ Time-of-flight
 Can measure very large distances with great accuracy
 This is the approach that we will implement
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Photodetector
HV Power Supply
Front End Amplifier (Transimpedance Amp)
NIR optical filter
Receiver Lens

Pros
◦ Highly Sensitive Photodetectors
◦ Make use of avalanche multiplication for increased
gain
◦ High Speed
◦ Designed for rangefinder applications
◦ Allows for larger maximum range detection

Cons
◦ Require HV reverse bias to get maximum gain
◦ Exhibit higher dark current than alternatives
◦ Small active area makes alignment difficult
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Peak Spectral Response
Cost and Availability
Minimum Dark Current
Required Bias Voltage
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Enhanced for NIR detection at 900nm
Spectral Response at M = 100
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Low noise equivalent power = 10fW/√Hz
TO-52 Package allows for easy mounting
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Proportional Input/Output Voltage
250VDC when full 5V input applied
Low peak-to-peak ripple (<1%)
Maximum Output Current 4mA
Low turn on voltage of 0.7V
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Converts photocurrent into voltage
High Slew Rate at 290V/µs
Low Input Noise Voltage 7nV/√HZ
FREE—Sampled
0.9
0.8
0.7
Transmission
0.6
0.5
0.4
0.3
0.2

0.1
0
860 870 880 890 900 910 920 930 940 950
Wavelenth in nm
Filter Specs
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2 in X 2in X .1in
CWL 905.9nm
BBW 54.0nm
Peak transmission 79%
Lens Tube Assembly
Receiver
Electronics

Prevent False Alarms
◦ Capture as much energy as possible
◦ Keep noise floor low
◦ Set threshold
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Output Power—Need high power laser diode
to meet maximum range criterion
Pulsewidth—Must have short pulsewidth to
have high axial (range) resolution (V x τp)
Wavelength—Transmitter near peak
responsivity of photodetector.
Beam Divergence—low divergence angle to
ensure maximum energy on target
HA!

SPL-PL-90_3
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TO-18 Package
Divergence 9 x 25 gradient degrees
Minimum Rise/Fall time 1ns
Threshold Current 0.75A
Peak wavelength 905nm
Power output 75W
Peak Current 40A
Typical Voltage 9V
Pulsewidth 5-100ns
5mm
5.9mm

Pros
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Very small in size at 1”x2.5”
Produces fixed pulsewidth at 15ns
Can produce up to 50A diode drive current
Diode mounts easily to CCA. (Radial or Axial
options)
Cons
◦ Also requires high voltage source
◦ 33ns propagation delay
◦ Difficult T-zero capture

Supply Current
◦ Ips = (Cpfn + Cfet + Cstray) * Vin * f
◦ Ips = (4000pF + 120pF + 430pF) *195V *1Hz
=0.9µA
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Output Current
◦ Directly dependent on HV supply (195V is max)

JP1 Connection
Pin 1
Pin 2
Pin 3
Pin 4
Pin 5
Pin 10
Ground
15V @ 1mA (support power)
Ground
Gate (Trigger) 5V
Ground
HV in (0 - 195V @ Ips)
Transmitter
Electronics

High Voltage

15V
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10-13V
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±5V
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5V

3.3V
◦ Diode Driver Board – 195Vmax
◦ Avalanche Photodiode – 230V
◦ Diode Driver Board
◦ Camera System
◦ Comparator
◦ Op Amps
◦ High Voltage Power Supply
◦ Microprocessor
◦ TDC

Designed and
Build using
ExpressPCB
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Creates a digital value for the laser pulses
time of flight from the transmitter to the
receiver.
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2 channels with 50 ps rms resolution
Measurement from 3.5ns to 1.8ms
Fire pulse generator
I/O voltage 1.8v – 5.5v
Core voltage 1.8 – 3.6v
4 wire SPI interface
QFN 32 Package
5mm
5mm

Microcontroller
◦ Programming Language: C
◦ Development Environment: Arduino Uno IDE
◦ Handles data collection and peripheral control
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GUI
◦ Programming Language: C#
◦ Development Environment: MS Visual Studio
◦ Receives user input and displays relevant
information
GPS
Compass
MCU
XBee
TDC
Pan & Tilt
Clock Speed
Core Size
I/O Pins
Package Size
Memory
UART/I2C/SPI/PMW
Operating Voltage
Price
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16 MHz
8 bit
14
DIP 28
32 kB
2/1/2/6
1.8 – 5.5V
$6.27
Mounted on Arduino development board
Arduino Uno development environment compatibility
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C Programming language
Allows for flexible troubleshooting
Large support community
SPI, I2C, & Serial libraries
Input Voltage
Input Current
Baud Rate
C/A code
Comm. Protocol
Accuracy
Price
4.5 – 6.5V
44 mA
4800
1.023 MHz
UART; RS-232
5m WAAS
$59.95
5cm
5cm
Input Voltage
Input Current
Field Range
Resolution
Comm. Protocol
Weight
Price
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2.7 – 3V
2 – 10mA
0.1 gauss
0.5 degrees
I2C
0.14 grams
$34.95
Two axis digital compass
Provides heading in degrees from
magnetic north
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100ft radial distance
Omni-directional link
Low Power Consumption
Input Voltage
RX/TX Current
Transmit Power
TX Sensitivity
RF Data Rate
Baud Rate
Frequency Band
Indoor Range
Outdoor Range
Protocol
Antenna
Price
2.8 – 3.6V
40 mA
2 mW (+3 dBm)
-98 dBm
250 Kbps
1200 – 1 Mbps
2.4 GHz
133ft
400ft
Zigbee (802.15.4)
Whip (dipole)
$25.95 (X2)
3cm
3cm
Operating Voltage
Operating Speed (6V)
Stall Torque
Operating Angle
Current Drain (6V)
Motor Type
Weight
Price
4.8 – 6V
.18 sec/600
83.3 oz*in
450
8.8 mA / 180 mA
3 Pole Ferrite
1.59 oz
$16.99
Weight (w/o servos)
Tilt Swing
Max. Payload
Price
5.5 oz
135o
2 lbs
$45.99

DIY Security Camera Kit
◦ NTSC format
◦ 510x492 pixels

900MHz Tx/Rx combo
Connect
to XBee
and
Video
Open
GUI
no
Poll
GPS
User
Input
yes
Fire
Laser
Poll
Compass
Display
Info
Move
Camera
PositionalData
Target
RangeFinder
- double CompassHeading
+ PositionalData targetData
+ PositionalData Info
- double latitude
+ RangeFinder rangefinderData
+ int distance
- CalculateGPS()
- PollGPS()
- DisplayData()
- PollCompass()
- string LatitudeHeading
- double longitude
- string LongitudeHeading
- PollLaser()
- DisplayData()

Given:
◦ Self GPS Coordinates
 Latitude (N/S ddmm.mmmm)
 Longitude (E/W ddmm.mmmm)
◦ Distance to target (m)
◦ Heading clockwise from magnetic north (deg)

Calculate:
◦ Target GPS Coordinates
 Latitude (N/S ddmm.mmmm)
 Longitude (E/W ddmm.mmmm)

Spherical Law of Cosines
lat2 = sin-1[ sin(lat1)*cos(d/R) + cos(lat1)*sin(d/R)*cos(Θ) ]
lon2 = lon1 + tan-12 cos(lat1)*sin(d/R)*sin(Θ)
cos(d/R) - sin(lat1)*sin(lat2)
[
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Self GPS coordinates (lat1, lon1)
Distance to target (d)
Heading (Θ)
Radius of the earth (R)
Target GPS coordinates (lat2, lon2)
]
Subsystem
Cost Analysis Budget
Laser System
Time to Digital Conversion
Camera System
Compass Module
GPS Module
Wireless System
Microcontroller
Power System
Mounting Fixture and Servo Motors
PCB Construction
TOTALS:
$770.29
$70.00
$0.00
$35.00
$79.99
$50.00
$45.00
$200.00
$75.00
$115.00
$1,440.28
$850.00
$50.00
$100.00
$50.00
$100.00
$100.00
$50.00
$25.00
$100.00
$75.00
$1,500.00
Rangefinder Components
Quantity
2
1
1
1
1
1
1
2
1
1
Part Name
Laser Diode OSRAM SPL PL 90_3
Diode Driver IXYS PCO 7110-50-15
APD Pacific Silicon AD230-9 TO52-S1
Optical Band Pass Filter
Laser Diode Collimation Tube
Receiver Extension Tube
Receiver Lens
HV Power Supply EMCO A025
Op-Amp TI OPA656
Assorted Resistors/Capacitors
Cost
$55.00
$207.20
$92.53
$30.00
$15.00
$140.00
$34.00
$65.78
$0.00
$10.00
Total
$110.00
$207.20
$92.53
$30.00
$15.00
$140.00
$34.00
$131.56
$0.00
$10.00
Component/Task
Critical Design Review
Condensed Final Report
Final Presentation
Due Date
20-Sep
2-Dec
2-Dec
David
X
X
X
Responsibilities
Ricardo
Nick
X
X
X
Shane
% Complete
X
X
X
100%
0%
0%
X
X
X
PHASE 1 - Components
97%
GPS
100%
Microcontroller Communication
4-Sep
Data Manipulation in GUI
4-Sep
X
100%
X
100%
Compass
Microcontroller Communication
Data Manipulation in GUI
100%
11-Sep
11-Sep
X
100%
100%
X
Camera
Wireless Communication
Video in GUI
Optics
100%
18-Sep
18-Sep
18-Sep
X
100%
100%
100%
X
X
Servos
Microcontroller Communication
Hardware Setup
100%
25-Sep
25-Sep
X
100%
100%
X
Wireless System
Microcontroller Interface
GUI Interface
100%
30-Sep
30-Sep
X
X
30-Sep
X
100%
100%
Power System
Hardware Setup
100%
X
X
X
Laser Tx
Hardware Setup
Optics
Calibration
11-Sep
11-Sep
11-Sep
X
X
X
X
X
X
100%
100%
100%
25-Sep
25-Sep
25-Sep
X
X
X
X
X
X
100%
100%
10%
Laser Rx
Hardware Setup
Optics
Calibration
70%
Time to Digital
Microcontroller Communication
Calibration
100%
100%
100%
2-Oct
2-Oct
X
X
X
David
Ricardo
100%
100%
Nick
Shane
PHASE 2 - System Integration
100%
GUI
100%
Target GPS Algorithm
Live Video
Servo Control
Laser Control
9-Oct
16-Oct
23-Oct
30-Oct
X
X
X
X
Camera, Laser Tx/Rx Alignment
Properly mounted components
Compact Design
16-Oct
23-Oct
30-Oct
X
X
X
Designed
Manufactured
16-Oct
30-Oct
X
X
100%
100%
100%
100%
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Housing
100%
100%
100%
100%
PCB
100%
100%
100%
PHASE 3 - Testing
79%
Testing
Rangefinder
GPS
Compass
Servo Control
Algorithm
GUI
79%
13-Nov
6-Nov
6-Nov
6-Nov
6-Nov
13-Nov
X
X
X
X
X
X
X
50%
75%
75%
75%
100%
100%
X
X
X
David
Ricardo
Nick
Shane
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Environmental conditions
Laser transmitter and receiver alignment
Divergence
t0 Timing
Cost
◦ Replacing broken parts
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Compass and GPS polling
Noise
QUESTIONS?