Lance Ellerbe - BS EE
Jamal Maduro - BS CpE
Peter Rivera - BS ME
Anthony Sabido - BS ME
1
2
Project Overview
Develop a self-contained network of tracked surface drifters for
near coastal application.
Housing
Electronics
Power System
GPS receiver
Radio transceiver
Microcontroller
Any of these drifters within range of the base station will then be
able to send all the information from all other drifters, thus
providing a self-contained drifter network.
 Many such drifters are deployed globally by the National Oceanic
and Atmospheric Administration (NOAA) as part of the world
climate observation program.
3
Electrical Components
 Microcontroller:
 TI (Texas Instruments) MSP430G2553 microcontroller
 Radio Transceiver
 XBee-Pro XSC RF module’s
 GPS module:
 Maestro A2100
 Battery
 Lithium ion
 Temperature Sensor
 Maxim DS18B20
4
General Layout
5
Color Coded Circuit Connections
6
Engineer: Jamal Maduro
7
Microcontroller
8
Microcontroller
9
MSP430G2553 Functional Block Diagram
10
Microcontroller Clock Speed - Voltage
11
Microcontroller Clock Speed - Current
12
Microcontroller Low Power Modes
13
System Flow Chart
14
Microcontroller Architecture
15
16
XBee Functional Block Diagram
17
XBee Modes of Operation
18
XBee Transmit State Machine
19
XBee Receive State Machine
20
XBee Data Verification Chain
21
XBee Pin Out Table 1
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XBee Pin Out Table 2
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Radio Transceiver
 Output power(Pt) = 30dbm (1W)
 Transmitting Gain(Gt) = 16 dBi
 Receiving Gain (Gr)= 16 dBi
 Frequency Band = 902 – 928MHz ISM Band
 Distance (d)= 15 miles (24.14016 kilometers)
= -57.348dBm
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25
GPS Diagram
26
GPS Pin Out Table 1
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GPS Pin Out Table 2
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Engineer: Lance Ellerbe
29
Temperature Sensor
Overview
 Compared to the thermistor, the DS18B20 has
memory and thus the temperature can be
held until a more convenient time when the
data can be logged.
 1 temperature reading per GPS fix
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Temperature Sensor
Maxim DS18B20
 Power Supply Range is 3.0V to 5.5V
 Can read temperatures from -55°C to +125°C (-67°F to
+257°F) with an accuracy of ±0.5°C from -10°C to
+85°C
 Converts Temperature to 12-Bit Digital Word in 750ms
(Max)
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Temperature Sensor
Interfacing Maxim DS18B20
 Digital temperature sensor that uses serial
communication through the DQ pin.
 The DQ pin operates in half duplex and
therefore cannot receive and send data at the
same time.
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Temperature Sensor
Interfacing Maxim DS18B20
33
Temperature Sensor
34
35
Power Systems
Overview
 Low Power Consumption
 Each must be able to operate on 3.3V maximum.
 The drifter network will be designed to use the least
amount of power when transmitting data.
 The power supply will be selected in order to supply the
adequate amount of amp-hours in order to provide
enough current for each electrical component to be
operational throughout its 15 day deployment.
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Power Systems
Current Component Selection PROGRESS:
 Xbee
 Operation Voltage: 3.0 -3.6VDC
 Current Draw:


Transmitting current: 256mA
Receiving Current: 50 mA
 Maestro A2100-A/B
 Operation Voltage: 3.0V - 3.3VDC
 Current Draw:

Peak Acquisition Current 45mA
 Microcontroller
 Operation Voltage: 1.8V - 3.6V
 Active mode: 230uA
 Standby Mode: 0.5uA
37
Power Systems
Ideal Battery Configuration
•Parallel configuration would be ideal to increase the amount of Amp-
Hours to supply the adequate amount of current to Microcontroller,
GPS module, Radio Transceiver and Temperature Sensor for a 15 day
period.
Using 4000 mAh
Batteries
EXAMPLE
Voltage = 3.3 V
V1
3.3 VDC
V2
3.3 VDC
V3
3.3 VDC
Current = 12000mAh
38
Power Systems
Voltage regulation
If battery chosen has a nominal voltage of more than 3.3 V, a
voltage regulator will need to be implemented to maximize
battery life and supply the correct operating voltage to the
components.
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Power Systems
Voltage Regulator
MAX882/MAX883/MAX884 line regulator
 The regulator input supply voltage can range from 2.7V to
11.5V
 Low Dropout Voltage: 220mV
 Fixed Output voltages: 3.3V and 5V
40
Power Systems
PCB protection
 Lithium Ion batteries must connect to a protection circuit
module to protect Li-Ion Battery from overcharge, over
discharge and to prevent accidental battery explosion
due to its extra high energy density.
Battery
41
Power Systems
Testing/ Verification
 The testing of this task will include a number of power
consumption tests. First, each electrical component will
be attached separately to a multimeter or oscilloscope to
validate that the component is operating within its
electrical specifications.
 Second, based on the results in the previous step the
results can be then used to tweak network parameters
such as transmission time or microprocessor algorithms
in an attempt to lower power consumption and increase
theoretical operation time.
42
Power Systems
 Risk:
 Temperature affecting battery characteristics
43
Power Systems
LiFePO4 Rechargeable 26650 Cell
Once all component selection has been
finalized, the battery will be chosen based the
voltage needed and the highest mAh that can
be found.
Xeno AA Size 3.6V Lithium Battery XL060F
Nominal Voltage
3.6V
Capacity
2400mAh (2.0V cutoff)
Operation
Temperature
Discharging:
85 oC (140F)
Max. Discharging
current
100mA
Price
$3.49
-55oC
-
Nominal Voltage
3.2 V
Capacity
10000mAh
Operation
Temperature
Discharging: - 10 60 oC (14 - 140 o F)
Max.
Discharging
current
10 A
Energy density
163.17 wh/kg
Price
$22.95
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Engineers: Anthony Sabido and Peter Rivera
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Concept Designs
Block Design
Cylindrical
Spherical
Design
Design
Semi-Spherical Design
Deciding Factors
 Cost
 The most critical factor. We can change the amount of
material used and needed, but we can’t change the
amount of money allotted.
 Stability
 Each design has it’s strengths and weaknesses.

Ex: Cylinders bob or tilt back and forth, blocks can snag, and
spheres will roll/pitch.
Deciding Factors (cont.)
 Ease of Fabrication
 There is a risk of losing these at sea or a need for more.
The Marine Lab should be able to reproduce them if
necessary.
 Impact Resistance and Weight
 Each are there own category but carry the same weight
in regards to decision making. Increasing impact
resistance typically increases weight. However, these are
weighted less than the other factors due to their effects
on performance and project completion.
Cost/Benefit Analysis
Aluminum
Tube
Glass-Fiber
Carbon-Fiber
Aluminum
Block
Glass-Fiber
Carbon-Fiber
Aluminum
Sphere
Glass-Fiber
Carbon-Fiber
Aluminum
Semi-Sphere
Glass-Fiber
Carbon-Fiber
Cost
Stability
(10)
7
-7010
-1002
-208
-8011
-1103
-306
-609
-901
-105
-5012
-1204
-40-
(10)
1
-102
-203
-304
-405
-506
-607
-708
-809
-9010
-10011
-11012
-120-
Ease of
Fabrication
(6)
6
-364
-243
-185
-3012
-7210
-601
-611
-669
-542
-128
-487
-42-
Impact
Resistance
(5)
2
-101
-53
-155
-254
-206
-3011
-5510
-5012
-608
-407
-359
-45-
Weight
(5)
3
-156
-3010
-502
-107
-3511
-551
-55
-259
-454
-208
-4012
-60-
Total
Rank
141
11
179
10
133
12
185
9
287
4
235
6
196
8
311
2
259
5
222
7
353
1
307
3
Overview
Major Features:
•Symmetric
•Semi-Circular Profile
•Fiberglass Hull
•Off-the-Shelf Deck
Plate
•Low Cost
•Easy Fabrication
•Symmetric Shape
•Semi-Circular Profile
Major Features:
•Symmetric
•Semi-Circular Profile
•Fiberglass Hull
•Off-the-Shelf Deck
Plate
•Low Cost
•Easy Fabrication
•
•
3 Part Designs
Maximum
Water Tightness
1. Top
2. Bowl
3. Screw-in
Deck Plate
Major Features:
•Symmetric
•Semi-Circular Profile
•Fiberglass Hull
•Off-the-Shelf Deck
Plate
•Low Cost
•Easy Fabrication
1
2
1. Top
2. Bowl
3. Screw-in
Deck Plate
3
Major Features:
•Symmetric
•Semi-Circular Profile
•Fiberglass Hull
•Off-the-Shelf Deck
Plate
•Low Cost
•Easy Fabrication
Material Selection
Fiberglass
 Low Density:
 Cloth: 2.6 g/cm3
 Resin: 1.3 g/cm3
 Low Cost
 205-B Slow hardener (0.86qt.): $45.99
 105-B Epoxy Resin (1 gal): $99.99
Sealing the Hull
 6” diameter deck



plate
Screw-on design
Made of Durable
ABS plastic
O-ring for water
tight seal
Low cost - $15.99
Dimensioning the Hull
Calculating Buoyancy
 Volume of water needed to be displaced:
 Density of water (not salt water) at 30 degrees
Celcius:
Mass Calculations
Component Mass
(New)
Antenna
9.1
g
GPS Antenna
9.1
g
GPS Module
4.5
g
Radio Transceiver
4.5
g
Batteries (2)
45.4
g
Board
40.0
g
Deck Plate
309.7
g
Hull
1401.5
g
1823.8
g
Total
Water Displacement
 Volume of water needed to be displaced (Vwater) is
1.831 x 10-3 cubic meters.
Vwater
Dimensions
- Drifter
Performance Analysis
Testing in Detail
 Floatation – Check water level. Our goal is to have the
drifter sit low enough in the water to avoid wind drag but
not too low that it loses stability.
 The Diameter can be increased or decreased to effect
floatation.
Testing in Detail
 Wavelength and Frequency
 We want to avoid accidentally matching the wavelength
of the test area witch would amplify the amount of roll
that the drifter experiences.
 An optimal diameter would be 1.5 – 2 times the
wavelength but we have not determined the
approximate wavelength of the test area and can not
compare the data at this moment.
Testing in Detail
 Adjusting the diameter however, risks our balance with the
wavelength, instead we can also adjust the vertical profile
of the drifter. For example, we can make it more cylindrical
to the top and bowl-like at the bottom.
 This change allows us to change the volume of water that
we’re displacing allowing for a change in water level.
Testing in Detail
 Dr. Oats
 Vibration testing was initially one of
our determined test methods but
after discussing the pros and cons
we determined it was not worth
pursuing.
 Impact testing was also examined
but we believe our electronics will
fail before the hull fails, therefore,
any testing would be to determine
the limit of the electronics. This test
would require us to purposely
destroy valuable material.
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Technical Risk
Risk
Exceeding baud rate limits
Probability
Low
Consequence
Severe
Mitigation
Strategy
Obey the baud rte limits for each
component
Risk
MCU communication function is
unavailable
Probability
Low
Consequence
Minor
Mitigation
Strategy
Communication can be implemented with
a “bit banging” method using general
purpose pins
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Schedule Risk
Risk
Personal Emergencies
Probability
Moderate
Consequence
Severe
Mitigation Strategy
A strategy to manage this risk would be to
ensure that all files used by all group
members can be accessible no matter who
is not available.
Risk
Resource Availability
Probability
Moderate
Consequence
Moderate
Mitigation Strategy A strategy to assessing this risk would be to
accommodate this possible setback in the
group's schedule.
73
Schedule Risk
Risk
Underestimate Microcontroller Software
Creation
Probability
High
Consequence
Moderate
Mitigation Strategy Give the programmer more than expected
time to program the microcontroller to ensure
they can finish without extending other
deadlines.
Risk
Marine Lab Changes Preliminary Requirements
Probability
Low
Consequence
Severe
Mitigation Strategy
Stay in contact with the FSU Marine Lab to ensure
that if any changes are made in the requirements we
will be knowledgeable of the changes and access
them as soon as possible.
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Budget Risk
Risk
Out of Stock Components
Probability
Low
Consequence
Moderate
Mitigation
Strategy
Looked up several different products and
vendors in case our first choice is not
available.
Risk
Replacing Lost/Damage Components
Probability
Low
Consequence
Severe
Mitigation Strategy Handle the components carefully and keep
them in their original packaging for
safekeeping.
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Budget Risk
Risk
Underestimated Quantities
Probability
Moderate
Consequence
Severe
Mitigation
Strategy
We plan to minimize the risk by very
carefully calculating the required amount
of material needed.
Risk
Requiring Developmental Tools
Probability
High
Consequence
Severe
Mitigation
Strategy
We plan to avoid the risk by adapting a
current breadboard and printed circuit
board to avoid further purchases.
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Project Overview - Timeline
TASK
START DATE DURATION (DAYS) END DATE
Assigned Team Members
Electronic Components: Product Research
9/18/2011
2
10/1/2011
Lance, Jamal
Simulation Programming in MATLAB
9/18/2011
14
10/1/2011
Jamal
Review Wireless Networking Theory
9/18/2011
14
10/1/2011
Lance, Jamal
Meet with Brian Wells
9/30/2011
1
9/30/2011
Anthony, Peter
Meet with High Performance Materials Institute
9/30/2011
1
9/30/2011
Anthony, Peter
Meet With Peter Lazarevich
9/30/2011
1
9/30/2011
All
Reverse Engineer Previous Drifter
9/30/2011
1
9/30/2011
All
Preliminary Housing Design
10/3/2011
8
10/10/2011
Anthony, Peter
Finalize Electronic Component selection
10/3/2011
1
10/3/2011
Lance, Jamal
Order Electronic components
10/4/2011
1
10/4/2011
Peter
Finalize Housing Design
10/10/2011
45
11/23/2011
Anthony, Peter
Measure & Weigh components
10/10/2011
1
10/10/2011
All
Conceptual Design Review Paper
11/17/2011
4
11/20/2011
All
Hull Design Finalized
11/17/2011
1
11/17/2011
Anthony, Peter
79
Timeline Cont.
Radio Antenna Selection
11/17/2011
5
11/21/2011
Lance, Jamal
GPS Antenna Selection
11/17/2011
5
11/22/2011
Lance, Jamal
Floatation Testing
11/18/2011
3
11/20/2011
Anthony, Peter
Hull Material Ordering
11/21/2011
1
11/21/2011
Anthony, Peter
GPS signal testing
11/21/2011
2
11/22/2011
All
11/29/2011
2
11/30/2011
All
1/9/2012
14
1/22/2012
Anthony, Peter
1/16/2012
7
1/22/2012
Anthony, Peter
2/3/2012
1
2/3/2012
All
2/4/2012
1
2/4/2012
Anthony, Peter
2/5/2012
1
2/5/2012
Anthony, Peter
Transmission Range
Testing
Start Initial Fabrication
of Hull
Water Tightness and
Flotation
Housing impact testing
Prototype Housing
Fabrication
Prototype Housing
Waterproof Testing
80
Project Overview - Timeline
Electronic Components: Product Research
Simulation Programming in MATLAB
Review Wireless Networking Theory
Meet with Brian Wells
Meet with High Performance Materials Institute
Meet With Peter Lazarevich
Reverse Engineer Previous Drifter
Preliminary Housing Design
Finalize Electronic Component selection
Order Electronic componenets
Finalize Housing Design
Measure & Weigh components
Conceptual Design Review Paper
Hull Design Finalized
Radio Antenna Selection
GPS Antenna Selection
Floatation Testing
Hull Material Ordering
GPS signal testing
Transmission Range Testing
Start Initial Fabrication of Hull
Water Tightness and Flotation
Housing impact testing
Prototype Housing Fabrication
Prototype Housing Waterproof Testing
14
14
14
1
1
1
1
8
1
1
45
1
4
1
5
5
3
1
2
81
Budget
Expenses
Quantity
Unit Price
Total
Microcontroller
8
$2.80
$25.70
Development Board
1
$13.69
$13.69
Radio Transceiver
5
$39.00
$195.00
USB-RS232 Adapter
5
$11.95
$78.53
RS232 Shifter
5
$13.95
$83.59
Radio Antenna
5
$8.00
$40.00
Printed Board
5
$15.10
$75.50
GPS Antenna
5
$22.95
$114.75
GPS Module
5
$19.44
$97.20
Thermistor
5
$5.00
$35.00
Battery
10
$9.00
$100.00
Fiberglass
15 sq ft
$ 4.74/sq ft
$71.10
Fiberglass Resin
1 qt
$39.99
$39.99
Fiberglass Hardener
0.44 pt
$19.99
$19.99
Deck Plate
5
$15.00
$75.00
Expenses Total
$1065.04
82
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Technical Report:
“Surface Circulation Study of Waters Near Ochlockonee Bay, Florida”
- Peter Lazarevich and Dr. Kevin Speer
Project Description :
“Tracking the coastal waters: a wireless network of shallow water drifters”
- FAMU-FSU College of Engineering
84
85
Network – (Legacy Network)
86
Network – (Revised Network)
87
Temperature Sensor
Interfacing Maxim DS18B20
 Parasitic Mode Power Supply
 The DS18B20 can draw power from the DQ data
line in parasitic mode without connecting VDD
to the drifter system power supply.
 Direct Power Supply
 Power Supply Range is 3.0V to 5.5V connected
to the VDD pin.
88
Power Systems
Time of Operation
 15 days of operation = 360 hours of operation
 Required GPS fixes: 10,000
 Number of Fixes in 15 days: GPS fix every 2.16 min or greater
 FCC rule: The average time of occupancy at any frequency
must not be larger than 0.4 seconds when using the frequency
hopping spread spectrum.
 Maximum current drawn per transmission/reception of all
electrical components:
Approximately 336mA
89
Power Systems
Power supply considerations:
 (1)Lithium Ion
 Lithium Manganese Nickel
 Lithium Polymer
 Nickel Cadmium (NiCad)
 Nickel Metal Hydride (NiMH)
 Photovoltaics
90
Power Systems
Lithium Ion Battery:
 These batteries are able to handle excessive current applications.
 Lithium batteries are great for long-term use.
 Lithium batteries also perform well in extreme temperatures.
 Increased life cycles over Nickel cadmium (NiCad) and Nickel Metal
Hydride (NiMH) batteries.
 Lithium ion batteries are also cheaper to manufacture than lithium
polymer batteries, so when cost is a factor, lithium ion is the choice.
 Much lower self-discharge rate than Nickel Metal Hydride (NiMH)
batteries.
 Wide variety of shapes and sizes efficiently fitting the devices they
power.
91
UART Test Code Part 1 of 3
92
UART Test Code Part 2 of 3
93
UART Test Code Part 3 of 3
94
XBee Module Risks
1
2
3
4
5
XBee-PRO XSC RF Module Risks
If the serial interface data rate is set higher than the RF data rate of the module,
the module will receive data from the host faster than it can transmit the data
over-the-air.
If the module is receiving a continuous stream of data, monitoring data on a
network, or awaiting acknowledgments for Retries functionality, any serial data
that arrives on the DI pin is placed in the DI Buffer. The data in the DI buffer will
be transmitted over-the-air when the module no longer detects RF data in the
network.
If the RF data rate is higher than the set interface data rate of the module, the
module will receive data from the transmitting module faster than it can send
the data to the host and data will be lost.
If the host does not allow the RF module to send data out of the DO buffer
because of hardware or software flow control data will be lost
Care must be taken not surpass the XBee's baud rate limit of 56,700 bps or data
will have a high chance of being corrupted and the drifter system could be
rendered unusable
95
Microcontroller Risks
1
2
3
4
MSP430G2553 Microcontroller Risks
The 16 kB flash for storing the main program may be inadequate for unaccounted
complexities in the overall integration of the MSP430G2553 with other
components
The 512 bytes of RAM may be inadequate for unaccounted data that would be
beneficial or necessary to store on the MSP430G2553
The digitally controlled oscillator (DCO) is sensitive to temperature and may slow
down or speed up significantly which may cause all time dependent functions like
UART communications to introduce errors into data
The amount of pins may be inadequate to fully interface MSP430G2553 with all of
the necessary components
Since the MSP430G2553's functions are multiplexed there might be a function
that is needed but cannot be used because the pin it is on is currently configured
5
as another function. For example, if you need to use both timers but the pin with
one of the timers is currently being used as a serial communication device
96
GPS Risks
Maestro A2100 GPS Module Risks and Manufacturer Precautions
1
2
3
The A2100-A needs an external pull-up resistor to be configured for UART operation. Please
consider the pull-up resistor in your design or pull the GPIO up right after reset by other means.
The ON_OFF input of the A2100-A needs to be connected to a push-pull output of a
microprocessor. For a wake-up, including the initial one after power on, a LOW-HIGH
transmission is mandatory.
It is recommended to connect the nRST pin of the A2100-A to an open collector / open drain
output of a microprocessor!
4
It is recommended to supply Vcc continuously! Use SiRFaware or other low power modes to
reduce power consumption of the module while no position information is required.
5
Care must be taken to implement an orderly shut-down sequence along with supplying power for
a certain period of time after initiating the shut-down sequence. Abrupt removal or drop of
power while the module is running has risks ranging from minor impact on TTFF to fatal
corruption of flash memory code area!
6
Generally, the quality of the GPS antenna chosen (passive or active) is of paramount importance
for the overall sensitivity of the GPS system. Losses through a bad antenna, long cables or tracks
or a bad antenna position can’t be compensated afterwards.
97