FAMU-FSU College of Engineering Department of Electrical and Computer Engineering

PROPOSAL

EEL4911C – ECE Senior Design Project I

Project title: Coastal Drifters

Team #: 7

Student team members: − Lance Ellerbe, electrical engineering (Email: mvc2560@yahoo.com) − Jamal Maduro, computer engineering (Email: jamalmaduro@ieee.org) − Peter Rivera, Mechanical Engineering (Email: rigoberto13@comcast.net) − Anthony Sabido, Mechanical Engineering (Email: ams07r@gmail.com)

Senior Design Project Instructor: Dr. Michael Frank

Technical Advisors: Dr. Kevin Speer, Dr. Oscar Chuy, Dr. Michael Frank

Submitted in partial fulfillment of the requirements for

EEL4911C – ECE Senior Design Project I

September 21, 2023

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Project Executive Summary

The purpose of this study was to observe circulation patterns that could explain the occurrence and timing of bacterial contamination at nearby beaches. These sites are regularly monitored by the Florida Department of Health as part of their “Florida Healthy Beaches Program”, which was initiated in 1998. In particular, Mashes Sands Beach, Wakulla County, has been monitored since 2000 and over that time there have been several advisories and warnings issued for contamination. During July 2007, Mashes Sands Beach has been under an advisory since mid-June. The field work began prior to this advisory, and continued for several weeks afterwards.

Using GPS positioning, any object may be tracked at Earth's surface with proper antenna placement. However, getting that information from remote autonomous platforms can be difficult and costly. This project's goal is to develop a system of networked, tracked surface drifters for near coastal application. Surface drifters, as their name implies, drift freely on the surface of the ocean. Many such drifters are deployed globally by NOAA as part of the world climate observation program. Near the coast, though, the NOAA buoys are too large to work (15m holey sock design) and additionally other technology is used to reduce the cost of telemetry. Very near the coast, in shallow water such as typically found on the West Florida Shelf and in Bays and estuaries, the standard coastal drifter design (CODE or "Davis" drifter) is again too large, and runs aground almost immediately.

In this project there will be a design for the housing and electronics package for a system of drifters that can receive GPS position, measure temperature, and record and radio this information to nearby drifters. 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. The base station can simply be one of the drifters fixed on a tower or other high location to be able to have line-of-sight access. RS-232 links the drifter to a PC to communicate the information received by the drifter, and plot the location of all drifters in real time.

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Table of Contents

Project Executive Summary............................................................................................................iiTable of Contents...........................................................................................................................iii1 Introduction..............................................................................................................................5

1.1 Acknowledgements..........................................................................................................51.2 Problem Statement...........................................................................................................51.3 Operating Environment...................................................................................................61.4 Intended Use(s) and Intended User(s).............................................................................61.5 Assumptions and Limitations..........................................................................................61.6 Expected End Product and Other Deliverables...............................................................7

2 Proposed Design......................................................................................................................72.1 Overview..........................................................................................................................72.2 Microcontroller..............................................................................................................102.3 GPS Module/GPS Receiver...........................................................................................12

2.3.1 GPS Response time: Cold, Warm, Hot Starts..........................................................122.3.2 GPS Accuracy..........................................................................................................132.3.3 GPS firmware control..............................................................................................132.3.4 GPS criteria..............................................................................................................14

2.4 Radio Module................................................................................................................142.4.1 Radio Range.............................................................................................................142.4.2 FCC Restriction.......................................................................................................152.4.3 Radio Criteria...........................................................................................................15

Table 9: Radio Comp.....................................................................................................................163 Statement of Work (SOW)....................................................................................................17

3.1 Task 1: Project Management.........................................................................................173.1.1 Objectives................................................................................................................173.1.2 Approach..................................................................................................................17

3.2 Task 2: Electronic Component Selection and Operation...............................................173.2.1 Objectives................................................................................................................173.2.2 Approach..................................................................................................................17

3.2.2.1 Subtask 2.1: Low Power Consumption............................................................173.2.2.1.1 Objectives.....................................................................................................173.2.2.1.2 Approach......................................................................................................173.2.2.1.3 Test/Verification Plan..................................................................................183.2.2.1.4 Outcomes of Task........................................................................................18

3.2.2.2 Subtask 2.2: Efficient Radio Transceiver in Wet Conditions..........................183.2.2.2.1 Objectives.....................................................................................................183.2.2.2.2 Approach......................................................................................................183.2.2.2.3 Test/Verification Plan..................................................................................183.2.2.2.4 Outcomes of Task........................................................................................18

3.2.2.3 Subtask 2.2: Thermistor Records Accurate Temperature................................183.2.2.3.1 Objectives.....................................................................................................183.2.2.3.2 Approach......................................................................................................183.2.2.3.3 Test/Verification Plan..................................................................................183.2.2.3.4 Outcomes of Task........................................................................................19

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3.2.2.4 Subtask 2.4: Obtain Adequate Frequency of GPS fixes...................................193.2.2.4.1 Objectives.....................................................................................................193.2.2.4.2 Approach......................................................................................................193.2.2.4.3 Test/Verification Plan..................................................................................193.2.2.4.4 Outcomes of Task........................................................................................19

3.2.3 Test/Verification Plan..............................................................................................193.2.4 Outcomes of Task....................................................................................................19

3.3 Task 3: Water Efficient Hull Shape and Material........................................................193.3.1 Objectives................................................................................................................193.3.2 Approach..................................................................................................................19

3.3.2.1 Subtask 2.1: Water Tightness...........................................................................203.3.2.1.1 Objectives.....................................................................................................203.3.2.1.2 Approach......................................................................................................203.3.2.1.3 Test/Verification Plan..................................................................................203.3.2.1.4 Outcomes of Task........................................................................................20

3.3.2.2 Subtask 2.2: Impact Resistance........................................................................203.3.2.2.1 Objectives.....................................................................................................203.3.2.2.2 Approach......................................................................................................203.3.2.2.3 Test/Verification Plan..................................................................................203.3.2.2.4 Outcomes of Task........................................................................................20

3.3.2.3 Subtask 2.3: Floatation.....................................................................................213.3.2.3.1 Objectives.....................................................................................................213.3.2.3.2 Approach......................................................................................................213.3.2.3.3 Test/Verification Plan..................................................................................213.3.2.3.4 Outcomes of Task........................................................................................21

3.3.3 Test/Verification Plan..............................................................................................213.3.4 Outcomes of Task....................................................................................................21

3.4 Task 4: End Product Design..........................................................................................213.4.1 Objectives................................................................................................................213.4.2 Approach..................................................................................................................213.4.3 Power Systems.........................................................................................................223.4.4 Microcontroller........................................................................................................223.4.5 GPS Module and Radio Transceiver.......................................................................223.4.6 Thermistor................................................................................................................223.4.7 Hull of Drifter..........................................................................................................22

3.5 Task 5: Testing..............................................................................................................233.5.1 Objectives................................................................................................................233.5.2 Approach..................................................................................................................23

3.5.2.1 Subtask 2.1: Network Between Drifters is Self-Healing..................................233.5.2.1.1 Objectives.....................................................................................................233.5.2.1.2 Approach......................................................................................................23

3.5.2.2 Subtask 2.2: GPS Data Stored Properly in Memory........................................233.5.2.2.1 Objectives.....................................................................................................233.5.2.2.2 Approach......................................................................................................23

3.5.2.3 Subtask 2.3: Range of a Complete Drifters Communication...........................233.5.2.3.1 Objectives.....................................................................................................23

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3.5.2.3.2 Approach......................................................................................................233.5.2.4 Subtask 2.4: Hull Keeps Floatation with Electrical Components in Place......24

3.5.2.4.1 Objectives.....................................................................................................243.5.2.4.2 Approach......................................................................................................24

3.5.2.5 Subtask 2.5: Hull Impact Resistance................................................................243.5.2.5.1 Objectives.....................................................................................................243.5.2.5.2 Approach......................................................................................................24

3.6 Documentation...............................................................................................................244 Risk Assessment....................................................................................................................245 Qualifications and Responsibilities of Project Team.............................................................276 Schedule.................................................................................................................................297 Budget Estimate.....................................................................................................................298 Deliverables...........................................................................................................................319 References..............................................................................................................................33Appendices (optional)....................................................................................................................33

1 Introduction

1.1 Acknowledgements

The Coastal Drifters team members would like to thank Dr. Kevin Speer and the FSU Marine Lab for providing a 1st generation drifter that we then reverse engineered to expedite the design process. The team would also like to thank Dr. Michael Frank and Dr. Oscar Chuy of the FAMU-FSU College of Engineering for the advice and guidance to enable us to make sound and practical design decisions. Lastly, we would like to thank the FAMU-FSU College of Engineering and the FSU Marine Lab for their financial contributions towards the Drifter project.

1.2 Problem Statement

Problem Statement

A network of drifters is needed to track and record the shallow-water currents of North Florida waterways such as the Ochlockonee bay. These drifters must be able to navigate through extremely shallow waters and remain operational if beached due to low tides or running aground. These drifters must also be able to communicate with other drifters to decrease the possibility of losing data. In addition, each individual drifter must have a significant range and battery life to also increase the amount of data being recorded and allow them to remain in use for a longer time.

General Solution

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These goals will be achieved by creating a network of five drifters. Each individual drifter will be a water-proof fiberglass vessel with a wide profile that has a saucer-like shape. This will increase the drifter’s buoyancy and allow it to float over shallower waters without reducing the hull’s structural integrity. Each drifter will be battery powered, and will locate itself using a global positioning system (GPS). Its position will then be sent to nearby drifters via radio transmission on the 915 MHz ISM (Industry, Scientific, Medical) band. In order to increase the probability that the full network is present despite the position of the nodes , each drifter will use an omni-directional antenna to communicate equally in all directions. Each drifter will programmed in C and will store information received by nearby drifters on flash memory. In order to decrease power consumption, each drifter will have a sleep mode and will only send and receive data at specified intervals; furthermore, an ultra-low powered microcontroller and using components that operate on 3.3 volts.

1.3 Operating Environment

For any end product other than simply a calculation, it is essential to know the environment to which the end product will be exposed or experience. For example, will the end product be exposed to dusty conditions, extreme temperatures, or rain or other weather elements? Is the end product likely to be dropped or thrown? This information is necessary in order to design an end product that can withstand the hazards to which it is expected to be exposed. This element shall be at least one paragraph in length.

1.4 Intended Use(s) and Intended User(s)

The drifters are intended to be used to track the flow of water in shallow areas on the east coast of the United States where larger buoys are impractical. These drifters will form a wireless sensor network to log positions over a period of time which can then be plotted on a map to examine the current flow. When the user(s) reach the intended start position, they simply need to turn on the drifter and place it in the water. When deemed necessary, the user(s) can use the GPS signal broadcast by each drifter to find and collect them.The intended users of these drifters are the staff at the FSU Marine & Coastal Lab and any associates they deem appropriate. The users should have a medium understanding of electronics and medium computer skills in order to interpret the data.

1.5 Assumptions and Limitations

Assumptions By sourcing components to achieve a radio range that is double the required range, the

network will still satisfy the minimum radio range after interference and attenuation have affected the signal.

The batteries have a charge of 4000 Amp-Hours and a voltage of 3.7 Volts. The microcontroller has enough memory space to store the main program. The FSU Marine Lab will be the sole users of the drifters.

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A helical antenna will increase the ability of the GPS module to locate satellites. Fiberglass will not cause any significant interference with electrical signals.

Limitations Weather may disrupt the drifter’s testing schedules. The drifter must be able to operate for at least 15 days (REQF-01). Each drifter must record at least 6000 GPS fixes (REQF-02). Each drifter must have a minimum range of 5 kilometers (REQF-03). The maximum weight of each drifter must be 0.5 kilograms (REQF-04). The maximum height of each drifter must be 10 cm or 20 cm with an antenna (REQF-

05). The cost of the materials and components may not exceed $1000 for the fabrication of 5

drifters (CONS-01).

1.6 Expected End Product and Other Deliverables

There will be three deliverables that will constitute the end product: a drifter with increased specifications compared to the 1st generation model, a meshed network consisting of four drifters and one base station, and software capable of translating the data (GPS fixes) into a easily usable format.

Drifter:

Each individual drifter will have increased specifications in every area when compared to the original drifter designed and fabricated by Peter Lazarevich. The drifters will have a longer operating time, greater transmission range, and will be lower in cost. In addition, each drifter will be able to track currents through shallower waters, have a lower weight than the 1st generation drifter, and will maintain data transmission and reception while being beached. Specific capabilities and specifications of the drifter may be found in sections 2.2 (CAP-01 to 07), 3.1 (REQF-01 to 08) and 3.2 (REQN-01 to 03) found in the Drifter’s Needs Analysis and Requirements Document.

Network:

The network that we will provide the FSU Marine lab will consist of 5 individual drifters capable of sending and recording GPS fixes from other drifters. Information from nearby drifters will be stored within each individual drifter in a data logger, creating a collection of data in each drifter gathered by other drifters within range. This will drastically reduce the chances of losing data due to drifters getting out of range or getting lost. A variant of the drifter will be used as a base station to monitor and aide in the retrieval of the deployed devices. The base station shall remain with the users and will only be in use while monitoring the drifters at sea and for the recollection of the four drifters.

Software:

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Software will be provided that will allow the users to decode the data transmitted by each drifter. This software will change the data received into a text document and allow for the data to be manipulated as desired.

2 Proposed Design

2.1 Overview

The basic concept of the drifter system shown below in figure 1 is based on a previous design used by the FSU Marine Lab. The key components used in the system are a GPS module, a microcontroller, and a radio transceiver module.

Figure 1: Basic Drifter System Top Level Diagram

The GPS module receives a fix (confirmed location) from three or more global navigation satellite system (GNSS) satellites and sends the data to a receiving pin (Rx) in the microcontroller. It should be noted that the drifter system only utilizes positioning in two-dimensions (latitude and longitude) that only require three satellites as opposed to positioning in three-dimensions (latitude, longitude, and elevation) that require four satellites. The microcontroller then processes and formats the relevant data from the National Marine Electronics Association (NMEA) data stream, or better known as NMEA sentences, and sends it through the transmission pin (Tx) to the radio module. The radio module then encapsulates the data packet with the necessary addressing and error checking packets and sends the data out to a base station using a star topology as shown in figure 2. The base station then logs the information and the process is repeated at a predefined time interval. While this system is adequate, it can be improved upon in both robustness and sensor capability.

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Figure 2: Drifter Star Topology

The basic concept of the drifter system is extended to accommodate new features such as ambient temperature measurements, network data logging, and utilization of an ad-hoc mesh network topology. The augmented top level design is shown below in figure 3.

Figure 3: Augmented Drifter System Top Level Diagram

The key differences between the drifter systems are that in the augmented drifter system the microcontroller processes and formats temperature data and also logs data from other nodes (drifters) in the tracking network. The process changes as follows: The GPS module receives a fix from three or more GNSS satellites and sends the data to a receiving pin in the microcontroller. The microcontroller then processes and formats the relevant data from the NMEA data sentences and sends it through the transmission pin to the radio module and also sends the formatted data through the necessary pin(s) to the data logger. The radio module then encapsulates the data packet with the necessary addressing and error checking packets and sends the data out to all nodes in the network. In addition to sending data out to the network, the radio module now receives data from the network, passes the data to the microcontroller through the

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necessary pin(s) and the microcontroller sends the data to the data logger which then writes the data to its onboard memory. Next, we will briefly examine how the data is distributed throughout the network.

The drifter network is modeled after a five-node wireless mesh ad-hoc network as shown in figure 4, or more specifically a wireless sensor network, that uses the XBee (variant of Zigbee) protocol to communicate within the personal area network (PAN) of drifters. Although the basic networking topology has been selected, the specific algorithms used to efficiently traverse the network have not been solidified.

Figure 4: Drifter Mesh Topology

In the following sections each key component is further discussed in detail including comparisons between different models and criteria for the selection and implementation into the final drifter system.

2.2 MicrocontrollerThe microcontroller is the core of the drifter system and is responsible for interpreting, processing, formatting, and transporting data internal to the system. The criteria for suitable microcontroller candidates are shown below in table 1.

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Criterion JustificationLow operation voltage that does not exceed 3.3V reduces energy consumption

Analog to digital (ADC) capabilities with a resolution of at least 8 bits

Allows the use of analog thermistors or other analog temperature sensors;Allows for a temperature range of -128 to 127 Fahrenheit or Celsius

Dual Inline Packaging (DIP) Facilitates development compatibility with standard breadboards and available low-cost development kits

At least 8 Kbytes of non-volatile memory, 256 Bytes of RAM, 16-bit registers

Accommodates medium sized low power programs;Accommodates higher accuracy floating point operations (compared to 8-bit)

At least 12 general purpose I/O pins Extends the number of controllable devicesExtends the number of available interrupt sources

Two universal serial interfaces are desired but only one is mandatory

Provides easy interface between microcontroller radio module;Provides easy interface between microcontroller and GPS module

Table 1: Microcontroller Criteria List

Due to the extremely low cost of the Launch Pad Value Line Development Kit (MSP-EXP430G2) sold for $4.30 from Texas Instruments, the three microcontrollers that were considered for the drifter system were all ultra-low power value line MSP430 microcontrollers made by Texas Instruments that are compatible with the development kit. Table 2 gives an overall summary of the relevant specifications when considering which microcontroller to use. The table is arranged according to microcontroller ideality (top is deemed better). Table 3 gives additional pros and cons of each of the three microcontrollers. After careful consideration the MSP430G2553 was chosen as the drifter system microcontroller.

MSP430 Part #

Non-Volatile Memory Capacity

Volatile

SRAM

General

Purpose I/O pins

ADC Register size

Numeric Price for Sort

FR5725 8 kB (FRAM) 1 kB 16 10-bit

SAR 16bit $2.05

G2553 16 kB (Flash) 512 B 16 10-bit

SAR 16bit $0.90

G2452 8 kB (Flash) 256 B 16 10-bit

SAR 16bit $0.70

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Table 2: Microcontroller Selection

MSP430 Part # Additional Pros Cons

FR5725

According to Texas instruments FRAM has the following advantages over flash: 1-- Consumes 250 times less power than flash: 9μA @12kB/s versus 220μA @12kB/s for flash 2-- Unified memory block can be dynamically configured as program, data, or info memory 3-- Can write 100 times faster than flash: 1400kB/s @ 730μA versus 12kB/s @ 2200μA 4-- Significantly larger write tolerance than flash: approx. 10 billion times more cycles 5-- Since it uses crystals instead of charge it's not susceptible to radiation 6-- Higher security and robustness due to its virtually undetectable write cycles 7-- Two Universal Serial Connection Interfaces as opposed to only one

1-- Does not have a DIP version 2-- Out of Stock 3-- Not available within time frame for this project

G2553

1-- 20 pin DIP version available 2-- Costs less then FRAM 3-- 5 power saving modes 4-- twice as much SRAM as the MPS430G2452 5-- 16MHz clock 6-- 16 kB Flash allows for larger programs in necessary

1-- Only one Universal Serial Interface (Tx Rx)

G2452

1-- 20 pin DIP version available 2-- Costs less then FRAM and MSP430G2553 3-- 5 power saving modes 4-- Relatively less power consumption than the MSP430G2452 5-- 16MHz clock

1-- Only one Universal Serial Interface (Tx Rx)

Table 3: Pros and Cons

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2.3 GPS Module/GPS ReceiverThe GPS module provides global positioning data that enables the drifter system, and hence the drifter network, to fulfill its primary objective of monitoring the coastal waters. What follows is an overview of concepts and terms and an explanation of why these attributes were important in selecting a specific GPS module.

2.3.1 GPS Response time: Cold, Warm, Hot Starts

GPS modules, or more specifically the GPS receiver chips within the module, use almanacs (information about the state of the entire GPS satellite constellation and trajectory data of every satellite's orbit) and ephemeris (an updated correction to a specific satellite's almanac data that is only broadcasted by said satellite) to find its location on earth. Acquisition time is the term used to define how fast a GPS receiver acquires its first fix. When the GPS module is activated without any prior data, more specifically location or coordinated universal time (UTC), then this is referred to as a cold start. Cold starts may also occur if a GPS module is turned off and it's prior almanac and ephemeris data is lost, erased, or a large change is position has occurred while the GPS is inactive. After a GPS module finds a satellite it uses the satellite to set its internal clock to UTC and waits until a satellite sends out it's almanac; starting after this point in the acquisition process is known as a warm start. Once the GPS module receives the almanac it then checks to see if the information is valid, which it does by listening for the next group of satellites that it needs to find its location; when this process is successful this is called a (hot) fix. Re-acquisition and acquisition are similar processes; however, a warm start and hot start are defined a little differently for re-acquisitions.

For hot starts during re-acquisition the GPS receiver remembers its location and which satellites it used to find its location, the almanac used, and the UTC. It then performs a reset and attempts to acquire satellites and calculate a new position based upon the previous information. This process is called re-acquisition and this scenario produces the fastest results. For warm starts during re-acquisition the GPS receiver remembers everything it did for a hot start except which satellites it used to find its location. It then performs a reset and attempts to obtain the satellite signals and calculate a new position. The receiver has a general idea of which satellites to look for because it knows its previous location, also the almanac helps identify which satellites are present and accessible. This scenario produces the second quickest results and also varies in time depending on the GPS model and methods used. Next, the actual content of GPS is examined.

Why is response time important? A fast acquisition and re-acquisition time reduces the amount of time a GPS module is active and therefore limits the power consumption. In order to obtain a fast acquisition and re-acquisition time the cold start, warm start, and hot start parameters should be significant criteria in the selection of a GPS module.

2.3.2 GPS Accuracy

The main objective for the creation of the drifters is to track and observe coastal waters; and in order to have valid data the accuracy of the GPS must be high enough to discern positions in narrow water passages covered in foliage and other obstructions. Furthermore, the drifters are going to be no more than 36 cm in length and 10 cm tall and partially submerged in water;

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therefore, in order to locate them efficiently during retrieval sorties the GPS should be accurate to within 5 meters to compensate for low visibility under certain atmospheric conditions.

Why is accuracy important? High GPS accuracy within 5 meters is critical to achieving the satisfactory and usable results when monitoring shallow, and sometimes narrow, coastal waters.

2.3.3 GPS firmware control

Most GPS modules output data in a format standardized by the National Marine Electronics Association (NMEA). The NMEA sentences contain a different array of information and amongst the total set of 58 standard NMEA sentences only the RMC has been deemed necessary for this project. The RMC data is structured as shown in Table 4:

$GPRMC,123519,A,4807.038,N,01131.000,E,022.4,084.4,230394,003.1,W*6A

RMC Recommended Minimum sentence C

121212 Fix taken at 12:12:12 UTCA Status A=active or V=Void.

4807.038,N Latitude 48 deg 07.038' N01131.000,E Longitude 11 deg 31.000' E

22.4 Speed over the ground in knots84.4 Track angle in degrees True

270490 Date - 27th of April 1990003.1,W Magnetic Variation

*6A The checksum data, always begins with *

Table 4: Breakdown of RMC sentence

The RMC sentence is used as such: the latitude and longitude are used to track the current and past locations of the drifters, the date and time are used to chronicle the journey of the drifters, the speed, magnetic variation and track angle are used to calculate trajectory which can be used to estimate when and where a drifter might exit the range of the network in which case an alert or signal can be sent to the base station and/or specific users. In order to reduce the amount of parsing the microcontroller would have to do to find the $GRMCA string, which signals the start of the RMCA sentence as shown above in table 3, it will be desirable to directly program or preset the GPS module to only output the RMC sentence.

Why is firmware programmability important? If the output of the GPS can be preprogrammed to only output relevant data for the operation of the drifter system then both the GPS module and microcontroller can do less work that results in an increase in power and speed efficiency, and decrease in energy consumption.

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2.3.4 GPS criteria From the previous sections pertaining to GPS response time, accuracy, and firmware control, a summary of criteria was compiled and is shown below in table 5.

Criterion JustificationLow operation voltage that does not exceed 3.3V reduces energy consumption

Use NMEA protocol easy to work with and interpret; appropriate for marine use

Customizable firmware control the output of the GPS data so the microcontroller's work is reduced

Fast (low) Cold, Warm, and Hot starts reduces response time; reduces energy consumption

UART communication capability allows microcontroller to easily interact with GPS module

Accuracy must be within 5 meters increases the chance of retrieval; decreases the time of retrieval; makes data more reliable and usable

Table 5: Summary of GPS criteria

With the recent discovery of the Sirf Star IV GPS modules and all their advantages over existing modules such as reduced power consumption on the order of micro amperes, reduced voltage as low as 1.8V, faster acquisition time, and low power tracking on the order of micro amperes, the GPS selection period has been extended and as of now there are only two candidates as shown below in table 6.

Part Name Chip Set

Hot/ Warm/ Cold

Start (s)

Acquisition

Sensitivity (dbm)

Operating

Voltage (V)

Price Accuracy (m)

Interface

Customizable

firmware

current draw (mA)

Venus634LPx Venus 1/29/29 -161 2.8 - 3.6 $39.0

02.5

(CEP) SPI yes 28

Jupiter F2Sirf

Star IV GSD4e

0.5/31/33 -143 1.75 -

1.9$35.0

02.5

(CEP)

UART, SPI, I2C

yes 30

Table 6: Tentative GPS selection

2.4 Radio ModuleThe Radio module is responsible for transmitting and receiving network data between the nodes in the wireless sensor network which includes the NMEA RMC sentence and the temperature readings from each node. The capabilities of the radio module are limited by cost, power consumption, and Federal Communications Commission (FCC) regulations.

2.4.1 Radio RangeWhile low energy consumption is the overall top priority for the drifter system, radio range is considered to be the second highest priority. The radio range is defined by the drifter network's

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radius of operation, which has been set at 5 km (3.1 miles). In other words, the drifter network's radial area coverage is 5 km but the individual range of each drifter can be less than 5 km. Most radio module specifications are written with respect to ideal situations where interference and attenuation are reduced, hence it will be wise to obtain a radio transceiver that has a range of at least two times the necessary range which in this case is 10 km (6.2 mi). There are a total number of five drifters and among those five only four will be deployed while one will act as a base station. Furthermore, if the drifters are arranged in a linear fashion as shown below in figure 5 then the limit for the range of each individual drifter can be calculated by

Rangenode=Rangenetwork

nnodes=10 km

4=2.5 km, therefore each node should have a transmission range

of 2.5 km in order to satisfy the overall network radial coverage of 10 km, which is the adjusted range that takes real-world interference and attenuation into consideration.

Figure 5: Drifter network radio range

Why is radio range important? Without a long radio range heavy attenuation and interference from the marine atmosphere can severely reduce the drifter network's radius of operation below the desired threshold.

2.4.2 FCC RestrictionIn order to reduce cost and increase range the 902 MHz - 928 MHz license-free Industrial, Scientific, and Medical (915 MHz ISM) frequency band will be utilized to transfer data within the drifter network. A summary of rules and regulations ordained by the FCC for the 915 MHz ISM bands using frequency hopping spread spectrum (FHSS) is shown below in table 7.

SUMMARRIZED FCC RULES AND REGULATIONSThe transmitter output power will be bounded to 1 watt (30 dBm)Effective isotropic radiation power (EIRP) will be bounded to 4 watts (36 dBm)The maximum antennae gain cannot exceed 16 dBi

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If the transmitter power is 30 dBm then for every 3 dBi over 6 dBi the transmitter power must be reduce by 1 dBmThe average time of occupancy at any frequency must not be larger than 0.4 seconds within any 10 second period.

Table 7: Relevant FCC rules and regulations

Why is adherence to FCC rules and regulations important? Any misuse of the ISM band or violation of the FCC rules and regulations could result in federal fines and other penalties that will ultimately render the drifter network unusable.

2.4.3 Radio Criteria

The criteria used to select the radio module for the drifter system is shown below in table 8 and the comparison between modules and final selection is shown in table 9.

Criterion JustificationLow operation voltage that does not exceed 3.3V reduces energy consumption

FCC compliant for the 915 MHz ISM band avoid federal infractions and penalties; keep network onlineData rate must high enough to transmit necessary information in a timely manner (does not violate FCC rules and regulations)

Reduces energy consumption; avoid federal infractions and penalties; keep network online

Fast (low) Cold, Warm, and Hot starts reduces response time; reduces energy consumption

UART communication capability allows microcontroller to easily interact with radio module

Table 8: Radio Criteria

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Xbee Mode

l

Operating

Voltage (V)

Line of sight

Range (km)

Mesh Protoc

ol

Transmit

Power (dBm)

High Gain

Antenna

Range (km)

Transmit

Current (mA)

Receive

Current (mA)

RF data rate

Price

Pro 900 3.0 - 3.6 3 Yes 17 10 210 50 154.6

kbps $39.00

Pro XSC 3.0 - 3.6 9.6 Yes 20 15 265 65 9.6

kbps $39.00

Xtend 2.8 - 5.5 24 Yes 30 64 730 80

9.6 kbps 155 kbps

$179.00

Table 9: Radio Comp

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3 Statement of Work (SOW)

3.1 Task 1: Project Management

3.1.1 ObjectivesThe Drifter team will effectively tackle the task of designing a workable device that can be reproduced and used in the field of Oceanography. In order to take on this task the team will use their knowledge in engineering to efficiently design an autonomous device that can track water currents in the Ochlockonee Bay. The network should be fully operational as long as one drifter is in line of sight of at least one other drifter and they are capable of interchanging data. The drifters should still be able to communicate whenever they become beached or their orientation does not give them a clear perpendicular view of the sky. The drifters should be recoverable in such a way that users spend no more than 5 minutes on average locating them once the radius of accuracy has been entered.

3.1.2 ApproachIn order to design the autonomous drifter the technical work will be divided into a number of areas: power systems, networking, embedded design and programming, and hull design. Each team member will be given one of these technical areas based on their proficiency. Each team member will be held accountable for work done in a specific technical area. Each team member will also keep other team members updated on their progress in their specific technical area of work.

3.2 Task 2: Electronic Component Selection and Operation

3.2.1 ObjectivesThis design relies upon three main components: a GPS receiver, radio transceiver, and a microprocessor controller, each available commercially as OEM components. The selection of components will be a task that will rely on many different factors based on the devices requirements and capabilities given by the customer.

3.2.2 ApproachSelection of the components was made based upon a compromise mainly between energy consumption, size, weight, and price. However, due to the short duration of this project, additional consideration was given to selecting components that could be integrated and developed with ease.

3.2.2.1 Subtask 2.1: Low Power Consumption

3.2.2.1.1 ObjectivesEach drifter must be able to operate for 15 days using a continuous power supply. Components will be selected in order to minimized power consumption over this period of time.

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3.2.2.1.2 ApproachThe drifter will be placed in an environment similar to the Ochlockonee Bay for an extended period of time. Power consumption will be monitored for a total of 24 hours (non-continuous) and the data collected will be used to interpolate the true power need for a 15 day operation time. The components selected will 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.

3.2.2.1.3 Test/Verification PlanThe testing of this task will include a number of power consumption tests. First, each electrical component will be attached separately to a multimeter to validate that the component is operating within its electrical specifications. Second, based on the results in the previous step the entire drifter system will be simulated in Matlab to determine the theoretical limitation to the operational time. The results can be then used to tweak network parameters such as transmission time or microprocessor algorithms and resource usage in an attempt to lower power consumption and increase theoretical operation time.

3.2.2.1.4 Outcomes of TaskWhen the most efficient battery supply is chosen then the drifter will able to be operational for up to 15 days.

3.2.2.2 Subtask 2.2: Efficient Radio Transceiver in Wet Conditions

3.2.2.2.1 ObjectivesEach drifter must be able to communicate with one another in various conditions . Each drifter should be able to transmit its GPS data back to a base station.

3.2.2.2.2 ApproachThe drifters will be placed in a body of water with salt content similar to that found in the Ochlockonee Bay and allowed to float on the surface. The distance between the drifters will gradually be made greater and the signal strength will be monitored; the distance will be flagged when the signal degrades below the allowable threshold. In addition to the distance, the characteristics of the surrounding environment will also be recorded and considered in the data analysis. The test will be conducted on clear sky conditions and in various rain conditions ranging from light rain to heavy rain.

3.2.2.2.3 Test/Verification PlanThe Xbee module's signal strength functions will be used to monitor the radio strength. A chart will be constructed listing the different ranges for each drifter in each weather condition; the data will be plotted and compared between the different environments (weather conditions and surroundings) and compiled into a table that will display what performance to expect in certain environments.

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3.2.2.2.4 Outcomes of TaskThe operational limitation and performance of the radio transceiver can be gauged depending on the operational environment.

3.2.2.3 Subtask 2.2: Thermistor Records Accurate Temperature

3.2.2.3.1 ObjectivesEach drifter must be able to record the temperature of the water that surrounds it as it drifts in the Ochlockonee Bay.

3.2.2.3.2 ApproachThe drifters will be set in containers of water with varying temperatures. They will take temperature readings every time when each respective drifter system updates.

3.2.2.3.3 Test/Verification PlanThe testing of this task will include a number temperature readings with thermistor and comparing it with the temperature from an actual thermometer in the same containment of water.

3.2.2.3.4 Outcomes of TaskThe drifter will be able to record its location and read temperature as it floats in water with varying temperatures.

3.2.2.4 Subtask 2.4: Obtain Adequate Frequency of GPS fixes

3.2.2.4.1 ObjectivesEach drifter must be able to receive at least 6000 GPS fixes in one operation over a 15 day period.

3.2.2.4.2 ApproachObserve and record the network GPS output for 3 hours. Analyze and calculate the average time between each GPS fix.

3.2.2.4.3 Test/Verification PlanAllow the network to operate for 3 hours with the drifters in close proximity to one another. Calculate the differences in time for all GPS drifter data logs.

3.2.2.4.4 Outcomes of TaskIf all the drifters show an average of 16.66 fixes for every hour then it can assumed that network will achieve a GPS resolution of 6000 fixes in 15 days.

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3.2.3 Test/Verification PlanThe fully operational drifter will be tested by taking it to a open area location that we can replicate real life situations. After verifying that radio transceivers are functional, 1 drifter will be left in a stationary location while all other radio transceivers are gradually moved away from the signal. Once radio transmissions fail, the distance between the testers and the drifter will be measured. If any problem occurs, we will go back to one of the preliminary test plans specified in the previous document. If no problems occur after testing the different situations, then the testing will be completed.

3.2.4 Outcomes of TaskAfter finalizing the test, the drifter should be ready to be operated in its entirety out in the Ochlockonee Bay.

3.3 Task 3: Water Efficient Hull Shape and Material

3.3.1 ObjectivesThe electrical components necessary for a drifter to operate must be kept safe from any environment or situation that may potentially disrupt or permanently stop it from operating as designed. The design of the hull must also optimize the performance of each drifter for the environment that it will be operating in.

3.3.2 ApproachThe environment that each drifter will operate in will be analyzed and the components that the hull will be housing will be individually weighed and dimensioned. A hull may be designed to optimize the drifter’s operation while protecting its components by taking into range of environment that the drifter will be operating in, the physical properties of its components, REQ-03 and REQ-04 (which govern the vertical dimensions and weight of each drifter).

3.3.2.1 Subtask 2.1: Water Tightness

3.3.2.1.1 ObjectivesThe hull must not allow water to penetrate through any crevices and potentially disrupt the drifter’s operation or damage its components (reference REQF-06). Any methods of increasing water tightness must not impede on accessing components when necessary.

3.3.2.1.2 ApproachThe amount of potential sources for leaks will be analyzed. The first source is the contact surfaces that form by creating a section of the hull that is removable allowing for access to the electronics. These surfaces include the lid (or cap) with the rest of the hull and any holes for fasteners. Other sources for potential leaks include the antenna and thermistor holes. Once all sources for leaks have been identified, they will be addressed by appropriately sealing the surfaces or eliminating the source of the leak entirely.

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3.3.2.1.3 Test/Verification PlanThe hull will be fully assembled without any electronic components that could get potentially harmed by water. The hull must have the antenna, however, which is necessary to test water tightness. The assembly will then be taken to a depth of 5 m and left alone for 24 hours. After the 24 hours pass, the drifter will be inspected for any leaks into the electronics compartment. For specific testing information regarding water tightness, reference REQT-06

3.3.2.1.4 Outcomes of TaskOnce the hull is retrieved from the bottom of the water source and completely dried off (externally), it will be opened. The inside of the hull should be completely devoid of any water, ensuring that the hull is indeed water proof up to a depth of 5 m.

3.3.2.2 Subtask 2.2: Impact Resistance

3.3.2.2.1 ObjectivesThe hull must be able to protect the components that it is housing from impacts that could either interrupt its operation or permanently damage its components.

3.3.2.2.2 ApproachThe amount of space necessary to house all of the drifter’s components will be analyzed allowing for a method of constraining all of the components in a safe manner that will minimize the possibility of damage due to any sudden impacts. In addition, the hull’s material must be able to withstand impacts from various objects, such as oyster beds, that could lead to leaking or damage to the electronics (reference REQF-07).

3.3.2.2.3 Test/Verification PlanA force will be applied to a test sample fabricated using the same materials and processes as the hull to observe failure (reference REQT-07). In addition, the entire drifter (fully assembled) should have no loose or moving parts inside. This can be determined by some gentle shaking.

3.3.2.2.4 Outcomes of TaskThe test sample should be able to withstand a force greater than 2.5N without failure of any kind. The hull, carefully fabricated in the exact manner that the test sample was, will be able to hold all of the electronic components and operate in various environments without damage.

3.3.2.3 Subtask 2.3: Floatation

3.3.2.3.1 ObjectivesThe drifter, fully assembled, must be able to float through significantly shallow waters. The drifter must be able to remain floating and tracking the current for as long as possible as the tide drops the water levels.

3.3.2.3.2 Approach

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The total mass of the legacy drifter’s components will be analyzed and new components will be sourced in an attempt to lower the overall weight. In addition, the hull will be designed to optimize weight and structural rigidity. The design of the hull will also attempt to displace the maximum amount of water possible while allowing the drifter to float as high as possible. REQF-04 and REQF-08 describe the mass and buoyancy requirements of this project.

3.3.2.3.3 Test/Verification PlanOnce the hull has been verified that it is indeed waterproof, the drifter will be fully assembled. The drifter will be placed in a tank of water with a depth 0.25m. In addition, the fully assembled drifter will be weighed to ensure that the weight is appropriate. For more information regarding the testing of overall weight and buoyancy, please reference REQT-04 and REQT-08 (respectively).

3.3.2.3.4 Outcomes of TaskThe drifter will have an optimum density that will allow it to float without obstruction across fresh water at a depth of 0.25m. This will ensure that the drifter can float across substantially low water levels while operating in the ocean and bay, where it will have higher buoyancy due to the salt water that it will be operating in.

3.3.3 Test/Verification PlanThe drifters, fully assembled, will be taken to the Ochlockonee Bay in North Florida for a field test.

3.3.4 Outcomes of TaskThe hull shall not hinder the performance of the drifter; that is, damage due to impact, water leakage or lack of buoyancy shall not the cause of any disruption of the drifter’s duties.

3.4 Task 4: End Product Design

3.4.1 ObjectivesAll the electrical component of drifter must be interfaced properly to work together operate according to what is desired. Also the electrical components must be able rest in the hull of the drifter without damaging the components when put in into a wet condition off the coast.

3.4.2 ApproachThe implementation will be broken in to technical responsibilities. The technical responsibilities include the power supply, communications network, and hull design. Each respective separate responsibilities, how they will be implement, and responsible for integration and testing.

3.4.3 Power SystemsThe design and implementation of the power systems will be perform by Lance Ellerbe and Jamal Maduro. This task will include power simulations based on the components selected for

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the drifter. They take into consideration all the important factors in designing adequate power supply based on component specifications such as voltage of operation and current drawn during active and sleep modes during the drifters period of operation. First they will perform simulations and based their power supply selection on the calculations made from various power supplies. They then order the necessary components and implement them into the full design of the drifter.

3.4.4 MicrocontrollerThe design and implementation of the microcontroller will be perform by Jamal Maduro. This task will include selecting and programming the microcontroller. He will observe the specifications of the microcontroller to make sure that it has all the capabilities needed to be interfaced in to the overall system and also that it is cost effective. He also will take into consideration all the important factors when programming the microcontroller based on component specifications such as voltage of operation and current drawn during active and sleep modes during the drifters period of operation. After deciding what microcontroller to choose then he will order the necessary components and implement them into the full design of the drifter.

3.4.5 GPS Module and Radio Transceiver

The design and implementation of the electronic communication components will be perform by Lance Ellerbe and Jamal Maduro. This task will include selecting and Interfacing both components into the overall system through the microcontroller pins. They will observe the specifications of the GPS module and Radio transceiver to make sure that it has all the capabilities needed to be interfaced in to the overall system and also that its cost effective. They also will take into consideration the how the communication devices will be affected by the microcontroller programming. Both communications components will be based on component specifications such as voltage of operation and current drawn during active and sleep modes during the drifters period of operation. After deciding what microcontroller to choose then they will order the necessary communication components and implement them into the full design of the drifter.

3.4.6 ThermistorThe design and implementation of the thermistor component will be perform by Lance Ellerbe and Jamal Maduro They will observe the specifications of the thermistor to make sure that it has all the capabilities needed to be interfaced in to the overall system and also that its cost effective. This task will include selecting and interfacing the thermistor into the overall system through the microcontroller pins. After deciding what microcontroller to choose then they will implement them into the full design of the drifter.

3.4.7 Hull of DrifterThe design and fabrication of the drifter’s hull will be tasked to Anthony Sabido and Peter Rivera. The hull must allow the drifter to float across significantly shallow waters and protect the electronic components that it is housing from impacts and water damage. In addition, the hull

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must allow for easy access to the electronics without compromising the drifter’s buoyancy and water tightness. Lastly, the hull must be feasibly duplicable and within the budget/capabilities of the FSU Marine Lab. They must be able to accurately remake the hull for the fabrication of duplicate drifters.

3.5 Task 5: Testing

3.5.1 ObjectivesOnce the design to the drifter is completed then the overall testing can begin to make sure all interfacing of all electrical components work working together as expected.

3.5.2 ApproachThe drifter will be placed in its environment of operation used in the manner that it was intended. If the drifter continues to operate in way that is desired then no further testing be needed.

3.5.2.1 Subtask 2.1: Network Between Drifters is Self-Healing

3.5.2.1.1 ObjectivesThe drifter communication will be tested to ensure network is stable no matter how many drifters are available to communicate.

3.5.2.1.2 ApproachThe drifter will put out into the environment that it will be operating in to test that drifter will communicate information properly between one another in all cases. If the drifter does not perform correctly then the drifter will then be analyzed and retested.

3.5.2.2 Subtask 2.2: GPS Data Stored Properly in Memory

3.5.2.2.1 ObjectivesThe drifters should will be tested to validate the storage of the GPS data of all drifters in the network when set out in the bay. Also based on the microcontroller programming GPS data must be organized properly to be interpreted by the customer.

3.5.2.2.2 ApproachThe drifter will put out into the environment that it will be operating in to test that drifter will communicate information properly between one another. The drifters then will be taken and the information on the data logger will be observed to see if data was stored as expected.

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3.5.2.3 Subtask 2.3: Range of a Complete Drifters Communication

3.5.2.3.1 ObjectivesThis test should check that the range of communication of the drifter as a whole should be near 5 miles.

3.5.2.3.2 ApproachThe drifter will put out into the environment thoroughly tested to ensure that range is consistent in all case out in the Ochlockonee Bay. If the drifter continues to operate in way that is desired then no further testing be needed. One drifter will be left in a stationary location while all other radio transceivers are gradually moved away from the signal. Once radio transmissions fail, the distance between the testers and the drifter will be measured. If the range does not meet expectations then further testing will occur.

3.5.2.4 Subtask 2.4: Hull Keeps Floatation with Electrical Components in Place

3.5.2.4.1 ObjectivesThis test should ensure that all electrical components will be completely functional when submerged in water.

3.5.2.4.2 ApproachThe drifter will put out into the environment thoroughly tested to ensure that the hull is stable in Ochlockonee Bay. The electrical components necessary for a drifter to operate must be kept safe from any environment or situation that may potentially disrupt or permanently stop it from operating as designed. If the drifter continues to operate in way that is desired then no further testing be needed.

3.5.2.5 Subtask 2.5: Hull Impact Resistance

3.5.2.5.1 ObjectivesThis test should ensure that the drifter will continue to communicate when it impacts a shoal or sand bar when tide changes.

3.5.2.5.2 ApproachThe drifter will put out into the environment thoroughly tested to ensure that the hull is stable in the vent that it is washed up on land in the Ochlockonee Bay. The drifter will be put in the situation that it may encounter the tide is changing. If the drifter in this situation stays upright and continues to communicate then there will be no more testing.

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3.6 Documentation This product will be given with a detailed report detailing the needs and requirements set forth by the FSU Marine Lab and the FAMU-FSU College of Engineering. Multiple engineering will be drawings presented to the FSU Marine Lab. These drawings include component specifications, schematics of the circuitry, dimensioned drawings of the hull, and technical directions for the fabrication and assembly of the drifter. Software will also be provided that will allow the sponsor to be able to decrypt the current data that the drifters collect. Due to composite materials being used for the fabrication of the drifter’s hull, the molds used for the composite lay-ups must be also given to the FSU Marine Lab.

4 Risk Assessment

Despite thoroughly scrutinizing the project’s needs analysis and requirements and designing a new drifter and network that best fits the FSU Marine Lab’s needs, there are still many risks that exist which may pose problems for this project. These risks may be assessed as components of physical constraints, monetary constraints, and general uncertainties involved with our project

Risks Associated with Physical Constraints

There are many physical constraints that must be taken into account when designing the drifters that were not explicitly described in the Needs Analysis and Requirements report. These constraints must be taken into account and compromises must be made in order to optimize our design. These risks, along with how our team will attempt to minimize the risks or prepare for the consequences, are stated below.

Sealing & Accessibility:

o Risks:

Any crevices needed for accessibility of components or to allow for an external antenna or temperature will be a source for potential leaks. By better sealing the hull, and consequently decreasing the potential for leaks, it becomes more difficult for accessing the components inside.

o Preventative Measures:

Decreasing the total amount of sources for leaks will be a major priority, as it decreases the potential for leaks without affecting component access. Keeping the components safe is a primary concern; however, the drifter will be designed to allow for feasible access to its components.

Weight & Durability:

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o Risks:

The hull’s primary job is to protect the internal components; however, it must be allow the drifter to float across shallow waters. Increasing the wall thickness on the hull will increase its durability but decrease its buoyancy (due to the increased weight).

o Preventative Measures:

The hull’s material will be sourced to find the optimum balance of weight, impact resistance, durability, and cost. We will then test different wall thicknesses to determine the minimum amount of material needed for fabricating the hull.

Timeline:

o Risks:

Many issues may arise that may be out of the teams control which could comprise our ability to make deadlines. Family emergencies, vandalism, or shipping errors are all examples of issues that could seriously hinder the drifter’s progress

o Preventative Measures:

The schedule will be designed to maximize the amount of time allotted for testing. Increased time for testing creates a buffer zone to iron out any issues we may come across.

On Site Testing:

o Risks:

The drifters must operate under many different conditions while out on the water. Weather issues may arise that could cause problems during testing, however. It would be unsafe and non-productive to test the drifters during a thunderstorm, for example.

o Preventative Measures:

The nature of our project requires us to test our drifter outdoors in the environment that it will operate in. Increasing the amount of tests for its components in a more controlled environment, however, can help decrease the total amount of time we will need to spend out at sea. This helps reduce the chances of encountering weather issues and reducing testing costs.

Transmission/Reception Range:

o Risks:

The radio transceiver’s range is greatly affected by the antenna that will be used. Both omni-directional and unidirectional antennas are offered. Omni-directional antennas decrease the overall range but increase the chances for successful

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transmission/reception of data. Unidirectional antennas operate in the exact opposite manner.

o Preventative Measures:

Our drifters will be subject to a wide variety of conditions where its direction will never be certain. For that reason, unidirectional antennas do not fit our needs. Other methods for increasing range will be analyzed, such as antenna length and/or material.

Data Package Loss (Error Tolerated):

o Risks:

The network of drifters being design must attempt to collect as much information possible from the other drifters, however, it must also accept be able to handle a percentage of data package loss.

o Preventative Measures:

An acceptable amount of data package loss must be accounted to when designing the drifters and network. The increased amount of drifters included in this network will increase the percentage of captured data, however, it must be accepted that a certain percentage of the data recorded will be lost.

Risks Monetary Constraints

Our allotted budget affects every aspect of the project. Below, we have attempted to identify major risks that may arise due to monetary constraints.

Battery Life:

o Risks:

Costs have a direct relationship with battery life. Although more spending does not necessarily translate to longer battery life, it does cost more to increase the drifter’s battery life. This means that all components that consume energy, as well as various performance aspects, are affected by costs. This includes: GPS accuracy, radio range, microcontroller, maximum data logged, and maximum range.

o Preventative Measures:

Extensive research will be done to ensure that we maximize the battery life of our drifter while remaining within our budget. This may only happen by individually assessing every component necessary and performing a power analysis to ensure that all of our needs and requirements are met.

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Replacement :

o Risks:

Despite the advances that will be made in the drifter’s range by creating a meshed network of drifters with improved specifications, there will still be a possibility that drifters will get lost or damaged. It will become very costly to replace drifters if they require expensive components. In addition, the fabrication of a duplicate drifter must be within the ability of the user.

o Preventative Measures:

By remaining within our budget, we will be ensuring that the drifters do not become too much of a burden if needed to be replaced. This is not sufficient, however, if the new drifters are as expensive and replaceable as its predecessor. Our drifters must make major advances in improving the life cycle, data collection and ease of duplication while remaining within a strict budget.

General Uncertainties

By creating a new drifter from the ground up, as well as networking a group of them together, we will be operating under many assumptions that cannot be taken for granted. Many of our components are being purchased without first-hand testing to ensure they exactly fit our application, creating a possibility that our drifter will not operate as designed. Examples of components whose performance may hinder our overall design are:

Battery: It may not produce the published power output that was used during our designs.

Radio Transceiver: The data transfer rate may not be fast enough, causing an increase in data loss.

Antenna: The actual range of the antenna may be less than was published.

In addition, there are uncertainties regarding the environment that need to be taken into account. Although our project aims to increase the range and recoverability of the previous drifters, the ocean currents may cause the drifters to get out of range of the network prematurely. It is entirely possible that the new drifters will be capable of operating for over 15 days and lose communication with the network after 24 hours.

5 Qualifications and Responsibilities of Project Team

Team 7 consists of one electrical, one computer, and two mechanical engineering students from the FAMU-FSU College of Engineering. With the combination of a vast number of skills and intelligence that each member brings to the team, Team 7 will be more than capable of producing a wireless network of shallow water drifters.

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5.1 Task Assignments

Task Team Member Skills and KnowledgeProject Leader, Power Systems, Networking, Circuit Design

Lance Ellerbe Power Systems, Digital Communications, Electronics

Secretary, Lead Microcontroller/FPGA Programming, Networking, Simulation

Jamal Maduro C, Assembly (8051), MIPS (RISC) , ARM (RISC), MATLAB, Digital Communications, Electronics

Treasurer, Webmaster, Hull design, material selection/testing, structural integrity, Impact Testing

Peter Rivera Mechanics, Materials, Design, Construction

Business Administrator, Hull design, material selection/testing, structural integrity, Impact Testing

Anthony Sabido Mechanics, Materials, Design, Construction

Qualifications

1. Lance Ellerbe

Lance Ellerbe is currently a Florida Agricultural and Mechanical University senior studying Electrical Engineering at the FAMU-FSU College of Engineering. He is the Team Leader of Team 7. His technical responsibilities will include Power Systems, Networking, and Circuit Design. Lance has taken classes in power systems, digital communications, microprocessors, and engineering management. He is a general member of NSBE and IEEE. He also assists in research with Dr. Witherspoon studying Lithium-Air batteries as part of FREEDM. With his wealth of experience, Lance will make a great leader and stop at nothing for an excellent product.

2. Jamal Maduro

Jamal Maduro is currently a Florida Agricultural and Mechanical University senior studying Computer Engineering at the FAMU-FSU College of Engineering. Before transferring to FAMU, Jamal studied Computer Engineering at the University of Central Florida; he is a member of NSBE, IEEE, and FGLSAMP. Jamal is the secretary for Team 7, lead Programmer, lead embedded systems engineer, and will also be working on the wireless sensor network and simulations. Jamal's relevant course work material include knowledge about electronics,

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microprocessors, FPGAs, wireless networks, digital communications, and computer architecture. Jamal spent a summer as an intern for Boeing working on control systems and has also done research in the areas of neural networks and fuzzy logic.

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3. Peter Rivera

Peter Rivera is currently a Florida State University senior studying Mechanical Engineering at the FAMU-FSU College of Engineering. He is the Treasurer and Webmaster for Team 7 and will be responsible for the hull of the drifters, which includes its material, construction and testing. He has taken classes as a transient student at Broward College and Florida International University. He has taken classes on fluids, a class on tools and several classes on materials. Peter is a member of the Society of Automotive Engineers and spent one year as the society’s webmaster. As a general member of SAE, Peter has participated in two separate build projects with a great deal of time around the tools necessary to complete this job and will use this knowledge to assure a properly built drifter hull.

4. Anthony Sabido

Anthony Sabido is currently a Florida State University senior studying Mechanical Engineering at the FAMU-FSU College of Engineering. He is the Business Administrator for Team 7. Anthony is also responsible for the hull of the drifters, which includes its material, construction and testing. He has taken classes on fluids, a class on tools, several classes on materials and a class on Finite Element Analysis. Anthony is a member of the Society of Automotive Engineers and spent one year as the society’s Vice-President, a separate year as captain of the Baja Team and currently serves as the Fundraising Officer. As a member of SAE, Anthony has participated in two separate build projects and on his own time also built a small hovercraft. He spent a summer working for AAR Aircraft Services Miami as a Lean Specialist and currently works under Dr. Collins as a tutor for middle school students as a part of the Ciscor Lab. Anthony has a great deal of practical experience in a variety areas and will make sure that the drifters designed by Team 7 are exactly what the sponsor desires.

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6 Schedule TASK START

DATEDURATION

(DAYS) END DATE Assigned Team Members

Electronic Components: Product Research 9/18/2011 14 10/1/2011 Lance, JamalSimulation Programming in MATLAB 9/18/2011 14 10/1/2011 JamalReview Wireless Networking Theory 9/18/2011 14 10/1/2011 Lance, Jamal

Meet with Brian Wells 9/30/2011 1 9/30/2011 Anthony, PeterMeet 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 AllReverse Engineer Previous Drifter 9/30/2011 1 9/30/2011 All

Preliminary Housing Design 10/3/2011 8 10/10/2011 Anthony, PeterFinalize 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

GPS signal testing 10/21/2011 1 10/21/2011 All

Transmission Range Testing 10/21/2011 1 10/21/2011 All

Housing impact testing 2/3/2012 1 2/3/2012 AllPrototype Housing Fabrication 2/4/2012 1 2/4/2012 Anthony, Peter

Prototype Housing Waterproof Testing 2/5/2012 1 2/5/2012 Anthony, Peter

Electronic Components: Product ResearchReview Wireless Networking Theory

Meet with High Performance Materials InstituteReverse Engineer Previous Drifter

Finalize Electronic Component selectionFinalize Housing Design

GPS signal testingHousing impact testing

Prototype Housing Waterproof Testing

9/18/2011

9/23/2011

9/28/2011

10/3/2011

10/8/2011

10/13/2011

10/18/2011

10/23/2011

10/28/2011

11/2/2011

11/7/2011

11/12/2011

11/17/2011

11/22/2011

141414 1111 811 451 11

Milestones:

1. September 1, 2011: Start Project

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2. September 29, 2011: Needs Analysis & Specifications3. October 3, 2011: Finalize Component Design4. October 10, 2011: Finalize Hull Design5. October 17, 2011: Sample microcontrollers ordered to be tested6. October 20, 2011: Project Proposal Completed

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7 Budget Estimate

Personnel CostPersonnel Effort(Hours) Base Pay (per hour) TotalLance Ellerbe 252 $ 30.00 $ 7,560.00 Jamal Maduro 252 $ 30.00 $ 7,560.00 Peter Rivera 252 $ 30.00 $ 7,560.00 Anthony Sabido 252 $ 30.00 $ 7,560.00 Subtotal     $ 30,240.00 Fringe Benefits (29%)     $ 8,769.60 Personnel Total     $ 39,009.60

ExpensesExpenses Quantity Unit Price TotalMicrocontroller 8 $ 2.17 $ 17.36 Development Board 1 $ 4.35 $ 4.35 Radio Transceiver 5 $ 39.00 $ 195.00 Radio Antenna 5 $ 8.00 $ 40.00 Printed Board 5 $ 15.10 $ 75.50 GPS Module 5 $ 22.95 $ 114.75 GPS Antenna 5 $ 39.95 $ 199.75 Thermistor 5 $ 10.00 $ 50.00 Battery 15 $ 3.00 $ 45.00 Fiberglass 50 sq ft $ 4.74/sq ft $ 237.00 Fiberglass Resin 1 gal $ 96.99 $ 96.99 Fiberglass Hardener 0.86 qt $ 42.99 $ 42.99 Expenses Total   $ 1,118.69

Total BudgetPersonnel Total     $ 39,009.60 Expenses Total     $ 1,118.69 Overhead(45%)     $ 18,057.73 Total Estimated Cost     $ 58,186.02

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8 Deliverables

Throughout the course of our project, our team will have designed and fabricated four drifters capable of recording currents over the period of 2-3 weeks. Further advances in the number of GPS fixes recorded, minimizing costs, and improving the recoverability of the drifters will have been made by creating a meshed network with the four new drifters. The completion of this project will consist of the finalization of multiple deliverables for the FSU Marine Lab and the FAMU-FSU College of Engineering.

Needs Analysis and Requirements:

A report detailing the needs and requirements set forth by the FSU Marine Lab and the FAMU-FSU College of Engineering. Along with these needs and requirements, the constraints that exist for this project and the various tests needed must be explicitly described. This document must allow everyone who reads it to have a clear and concise understanding of the project and all that it entails.

Project Proposal:

A document outlining the purpose of the coastal drifter, the justification for the project, the means and methods that are going to be used to fulfill project needs and requirements, and more importantly a more detailed explanation of how the drifter system works that was omitted in the Needs Analysis and Requirements report. The document will include tables that compare different components, pros and cons between different components, and figures illustrating basic ideas and concepts of the drifter system.

Design Reviews:

Following the completion of the project proposal, multiple design reviews must be completed and presented to the FSU Marine Lab and the FAMU-FSU College of Engineering. These design reviews will allow the sponsor and college to know the status of our project at various times. These reviews also help reduce the possibility of our project reaching completion only to find we did not meet the exact goals of the college and our sponsor.

Engineering Drawings:

Multiple engineering drawings must be completed and presented to the FSU Marine Lab. These drawings include component specifications, schematics of the circuitry, dimensioned drawings of the hull, and technical directions for the fabrication and assembly of the drifter. Although it is not explicitly stated that specific engineering drawings must be completed, these drawings will allow for others to analyze our design and replicate our work. This is especially important for the FSU Marine Lab due to their need to make duplicates of our drifters at a later time.

Drifters:

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Four complete drifters must be completed and presented to the FSU Marine Lab and the FAMU-FSU College of Engineering. These drifters must meet the needs and requirements specified by the sponsor, with well documented test results to verify the drifter’s performance. The drifters must be able to take and record GPS fixes and specified intervals and be able to transmit and receive their information to nearby drifters. These drifters must be ready for immediate field work at the time of presentation to the FSU Marine Lab.

Molds:

Due to composite materials being used for the fabrication of the drifter’s hull, the molds used for the composite lay-ups must be given to the FSU Marine Lab. This is necessary for the sponsor to be able to accurately duplicate our drifters. Once the drifters are presented to the sponsor, all molds and materials used for the fabrication of the drifters must also be handed over. It is important that this project does not end with the initial four drifters being designed, but that multiple more drifters can be fabricated for continuous field research.

Software:

In order for the power consumption in each drifter to be kept to a minimum, the data that each drifter stores and transmits must be compressed to take up as little memory as possible. Software will be provided that will allow users to uncompress the current data that the drifters collect. This will allow the users to plot and measure the current data in a user-friendly manner.

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9 References

[1] Ellerbe, Lance, Jamal Maduro, Peter Rivera, and Anthony Sabido. Drifters –

Specifications and Requirements. FSU Marine Lab. Web. 29 Sept. 2011.

[2] Federal Communications Commission (FCC) Home Page. Web. 18 Oct. 2011.

<http://FCC.gov>.

[3] Lazarevich, Peter, and Kevin Speer. Surface Drifters for Coastal and Estuarine Systems.

Web. 9 Sept. 2011.

[4] Lazarevich, Peter. Technical Report: Surface Circulation Study of Waters Near

Ochlockonee Bay, Florida. Tech. 2007. Print.

[5] National Marine Electronics Association - NMEA. Web. 18 Oct. 2011.

<http://nmea.org>.

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Appendix

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