Universal RF Communication System

Project Plan

Submitted: September 25, 2001 Revised: October 9, 2001

Client: ECPE Senior Design Faculty Advisors: John Lamont Ralph Patterson Team May02-06 Members: Tony Poon - Leader Daniel Fox Usman Tariq John Kenkel Daniel Dobson – Reporter

Table of Contents

TABLE OF CONTENTS ..................................................................................................I

LIST OF TABLES ........................................................................................................... II

LIST OF FIGURES ........................................................................................................III

ABSTRACT....................................................................................................................... 1

DEFINITION OF TERMS............................................................................................... 1 GENERAL BACKGROUND ................................................................................................. 2 TECHNICAL PROBLEM...................................................................................................... 2 OPERATING ENVIRONMENT ............................................................................................. 2 INTENDED USERS AND USES ............................................................................................ 2 ASSUMPTIONS AND LIMITATIONS..................................................................................... 3

DESIGN REQUIREMENTS ........................................................................................... 3 DESIGN OBJECTIVES ........................................................................................................ 3 THE DESIGN OBJECTIVES ARE THE GUIDELINES THAT WILL DIRECT THE PROJECT. THESE OBJECTIVES ARE LISTED BELOW. ...................................................................................... 3 FUNCTIONAL REQUIREMENTS .......................................................................................... 4 THE FUNCTIONAL REQUIREMENTS DEFINE THE REQUIRED FUNCTIONS THAT THE END PRODUCT WILL PERFORM. ................................................................................................ 4 DESIGN CONSTRAINTS ..................................................................................................... 4 MEASURABLE MILESTONES ............................................................................................. 5

END PRODUCT DESCRIPTION................................................................................... 6

APPROACH AND DESIGN............................................................................................ 6 TECHNICAL APPROACHES ................................................................................................ 6 TECHNICAL DESIGN ......................................................................................................... 6 TESTING DESCRIPTION..................................................................................................... 7 RISKS AND RISK MANAGEMENT ...................................................................................... 8

FINANCIAL BUDGET.................................................................................................... 9

PERSONNEL EFFORT BUDGET................................................................................. 9

PROJECT SCHEDULE................................................................................................. 10

PROJECT TEAM INFORMATION ............................................................................ 11

SUMMARY ..................................................................................................................... 11

REFERENCES................................................................................................................ 12

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List of Tables Table 1 – Estimated Project Cost........................................................................................ 9 Table 2 - Estimated Project Time in Hours ........................................................................ 9

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List of Figures Figure 1 – Design Block Diagram ...................................................................................... 6 Figure 1 - Project Schedule............................................................................................... 10

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Abstract Past projects in senior design have required the use of wireless communication systems which were either too expensive to buy commercially or too time consuming to develop internally. To alleviate both problems, a wireless communication system could be developed by a design team to be incorporated in future senior design projects. To this end, a radio frequency communication link will be developed using inexpensive components available commercially. The design will be of a form that will be easy to integrate and accommodate a broad range of applications with minimal modifications. The units built as a result of this project team will accommodate the senior design department’s wireless needs for years to come. Definition of Terms Transceiver Wireless component incorporating both transmit and receive functionality FM Frequency modulation – protocol for analog transmission over the air FSK Frequency shift keying – protocol for digital transmission over the air PCB Printed circuit board Glue logic Analog or digital circuitry supporting any given component

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Introduction General Background The universal RF communication system project is to design a wireless information exchange system for general applications. The design will be ultra-low power consuming and compact in physical size in the order of cm2. The end product should be easy to use and incorporate into senior design projects requiring wireless communication. Technical Problem The preliminary technical approaches are as follow:

1. Microcontroller-based design with minimal supporting components. The

microcontroller will be programmed using assembly. 2. Physical RF information exchange will be done using an RF transceiver. 3. User interface such as LCD output, keyboard, and speaker are all being evaluated. 4. Compact ultra-low noise power supply will be integrated into the end product. 5. PCB design will be implemented using OrCad schematic software. 6. An antenna will be used in combination with the RF transceiver.

Operating Environment The operating environment of this device can be both indoors and outdoors depending on the nature of the application and distance between communicating modules. It is assumed that the operating environment is clean, at room temperature, and has low humidity. Radio traffic density in the close proximity should be minimum. Intended Users and Uses This project primarily serves an academic purpose. Future senior design teams and researchers, involving use of RF communication links to employ wireless control and data transmission into their projects are the intended users of this device.

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Assumptions and Limitations Important assumptions are:

1. User interface will be designed assuming that users have basic knowledge of

computer programming. 2. RF transceiver will be chosen based on the assumption that the design will be

using a low speed transfer rate. 3. Final product will be functional assuming it is being used under the operating

environment previously mentioned. 4. All of the basic requirements will be identified up front and can be implemented.

Important limitations are: 1. RF communication channels will be limited to unlicensed radio frequencies. 2. Design implementation will be limited to total cost of all chosen parts. 3. Parts selection will be limited to availability. 4. Design complexity will be limited to a two-semester turn-around time.

Design Requirements Design Objectives The design objectives are the guidelines that will direct the project. These objectives are listed below.

1. Design a wireless solution for applications needed frequently in senior design projects. The design includes:

o Power supply o Microprocessor o RF components for transmitting and receiving o User interface o Antenna

2. Fabricate a compact and low cost solution that can be easily assembled.

o Low cost, off-the-shelf RF transceiver with suitable functionalities o Low cost, off-the-shelf microcontroller with adequate computing power o Minimal count of passive components

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3. Design should be compatible with a broad range of applications with minimal modifications.

4. The link should be a frequency-agile medium for a bi-directional RF link.

Functional Requirements The functional requirements define the required functions that the end product will perform.

1. The communication system should be able to transmit and receive frequencies in an unlicensed frequency band.

2. Two modes of operation must be available: FM for analog and FSK for digital. 3. The communication system will be capable of converting analog to digital before

sending and converting digital back to analog when receiving. 4. The project will incorporate a compact design, low power consumption, and a

sleep mode when not being used. Design Constraints An initial examination of the design requirements led to a compilation of constraints that will limit the form and function of the design. These constraints are listed below.

1. Parts: Components including the transceiver chip, microcontroller, antenna, and power supply must be interoperable for reliable communication.

2. Time:

Shipping and availability of parts will constrain the time period for this project. Care will be taken to ensure parts are acquired in a timely fashion.

3. Operating frequency:

The operation frequency must fall within the allowable RF range for the transceiver chip.

4. Operational modes:

At least three modes need to be implemented: FM for analog, FSK for digital, and sleep mode for low power consumption.

5. Resolution frequency:

The output frequency resolution will be limited based on the transceiver chip.

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6. Programming: The micro-controller will need to be programmed in assembly language for the different operating modes.

7. Interface:

The interface to the chip should be limited to an industry standard.

8. Portability: The product will have to fit on a small PCB while being able to contain all the components as modules or as one unit. Also, all components must be portable so they can be taken to on-site locations.

Measurable Milestones The success of this project will be based upon the timely completion of key events the project team sees as fundamental to completing the design. These milestones are listed and discussed below.

1. Project definition: The requirements of the product will be decided. All necessary functions and applications will be analyzed and satisfied. A market analysis of commercially available components will be conducted.

2. Project design:

A project design will be completed including schematics with complete build-of-material and hardware/software functional diagrams.

3. Working prototype:

A functional prototype will be built and operational. Component, software, and integration testing will be completed.

4. Product completed:

Fully operational product will be released including all supporting documentation.

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End Product Description The end product will be an inexpensive, off-the-shelf RF link capable of different modes of operation. This will allow other senior design teams to quickly incorporate a wireless communication link into their projects. The finished product will be a compact, high-speed, analog and digital wireless communication link complete with user documentation. Approach and Design Technical Approaches The approach to this project is to design a system that takes a user input, modulates the input data into appropriate schemes to be transmitted over a high carrier frequency. Glue logic will be implemented to accommodate for various interferences. Different implementations are being considered depending on the complexity of the applications to be included. Some possibilities are:

1. Single integrated design with all necessary functions 2. Modular design with separate function-specific blocks

Technical Design

A/D &D/A

EPROM User/Application

Transceiver Chip with glue-logic

Power Antenna

Microcontroller with glue-logic Interface

Figure 1 – Design Block Diagram

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1. User / application: Depending on the application, a generic user interface will have to be designed in order for the user to interact with the microcontroller.

2 Interface:

The interface should be an industry standard protocol for user robustness. Several methods of I/O will be considered including RS232, USB, a generic on/off, and analog.

3. Microcontroller:

An ultra-low power digital or analog microcontroller will be needed for data and control processing. This will determine the logic to both transmit and receive based on the inputs from the user and the mode settings.

4. EPROM:

Depending on the microcontroller requirements, an EPROM could be needed for boot-code storage.

5. Antenna:

A low cost antenna will be selected to transmit and receive signals. 6. Power supply:

The power supply will need to be small enough to fit in a compact size, yet will need to have the appropriate specs to operate the system. Noise in the supplied power will play an important role in the quality of the analog signal.

7. Transceiver chip with glue-logic:

The transceiver chip will be the main component in the design. It will be able to transmit and receive analog and digital, but only one at a time.

8. A/D and D/A converter:

A/D and D/A converters are needed for modulating and demodulating signals over the air. This may be integrated in the transceiver chip so no extra components are needed.

Testing Description Testing will begin on the component level. Each individual component will perform its required tasks separately before any integration is considered. Once all components are functional, different levels of integration tests will be performed. A prototype will be constructed to test the overall design for functionality. Once the prototype is functional, an assembled PCB will be fabricated and tested with all supported functions. A reliability test will also be performed in the RF layer to determine signal integrity. Finally, potential users will have a chance to evaluate our design. User feedbacks will then be employed towards the final optimization procedures.

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Risks and Risk Management In any endeavor there exist obstructions to success, some visible from the start and some not. Below is a list of problem areas seen by the team from the outset as risks to successful project completion.

1. Team member loss: Talent and knowledge are evenly distributed within the group, so a loss of any member will not tremendously affect productivity. However, this will reduce the number of hours planned for product completion.

2. Part unavailability:

Unavailability of chosen parts can greatly affect project progress, but in the highly competitive semiconductor market, a substitute can easily serve as a backup.

3. Design problem: Technical problems with implementing the functions could arise. In this instance,

additional help will be sought and alternative solutions created.

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Financial Budget The financial budget shows the expected costs for all project items. These figures are estimates and reflect the availability of free samples and student discounts. The project team members will fund all spending exceeding $100. Table 1 – Estimated Project Cost

Item Name: Amount: Project Poster $55.00 Components $60.00 PCB Fabrication $200.00 Mechanical / Packaging $20.00 Batteries $10.00 Miscellaneous Printing $10.00 Project Total: $355.00 Personnel Effort Budget The personnel effort budget shows the division of labor by both project area and person-hours. These figures are estimates and reflect the total project time required for each item including meetings, individual work, and group work. Table 2 - Estimated Project Time in Hours

Task Name: Dan Fox: Tony Poon: Daniel Dobson: John Kenkel: Usman Tariq: Total:Product Definition 20 20 16 20 18 94Research 8 8 7 10 8 41Pre-Design 11 12 11 14 12 60Design 8 8 9 13 14 52Software Design 5 5 3 3 3 19Procure Parts 2 4 2 2 2 12Functional Prototyping 37 38 32 36 30 143Revision A 27 28 25 26 25 131Revision B 10 11 8 10 7 46Documentation 8 9 8 8 8 41Final Verification 14 15 12 14 15 70 Class Deliverables 14 14 22 14 12 76 Total Per Person: 164 172 155 170 154 815

Team Total: 815

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Project Schedule The project schedule indicates the separate areas of work and their required time. Each area of work is broken into its specific components to more clearly show the work being completed. By following these guidelines the project can be completed on time.

Figure 1 - Project Schedule

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Project Team Information Team Members Dan Fox, CprE Daniel Dobson, EE John Kenkel, EE 1122 Hawthorn Ct. 919 6th St. # 21 5322 Hawthorn Ct Ames, IA 50010 Nevada, IA 50201 Ames, IA 50010 (515) 572-7808 (515) 382-5385 (515) 572_8040 foxy@iastate.edu dadobson@iastate.edu jkenkel@iastate.edu Tony Poon, CprE Usman Tariq, EE 4709 Steinbeck St. #14 4317 Lincoln Swing # 21 Ames, IA 50014 Ames, IA 50014 (515) 268-5015 (515) 292-1694 poony@iastate.edu utariq@iastate.edu Faculty Advisors John Lamont Ralph Patterson III 2215 Coover 2215 Coover Ames, IA 50011-3060 Ames, IA 50011-3060 Phone: (515) 294-3600 Phone: (515) 294-2428 Fax: (515) 294-6760 Fax: (515) 294-6760 jwlamont@iastate.edu repiii@iastate.edu

Summary The inspiration for this project stems from past senior design teams being unable to acquire a suitable wireless communication system due either to lack of money to buy a commercial unit or lack of time to design one. The solution proposed in this document solves both problems by bypassing both cost and time. The project is to design and fabricate a well-documented, easily integrated, application agile RF solution from commercially available components. Implementing this proposal will ensure future design teams will not be set back by incorporating wireless technology.

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References

1. “TRF6900A, Single-Chip RF Transceiver Datasheet.” Texas Instruments Mix Signal Processing Group. May. 2001. Texas Instruments Incorporated. <http://www-s.ti.com/sc/psheets/slas213g/slas213g.pdf>

2. “TRF6900/MSP430 EVK Application Report.” Texas

Instruments Wireless Communication Business Unit. May. 2001. Texas Instruments Incorporated. < http://www-s.ti.com/sc/psheets/swra032/swra032.pdf>

3. “MSP430x11x Mixed Signal Microcontrollers Datasheet.” Texas Instruments Mix Processing Signal Group. April 2000. Texas Instruments Incorporated. < http://www-s.ti.com/sc/psheets/slas196b/slas196b.pdf>

4. “Implementing a Bi-directional, Half-Duplex FSX RF Link.” Texas

Instruments Mix Processing Signal Group. March 2001. Texas Instruments Incorporated. < http://www-s.ti.com/sc/psheets/slaa121/slaa121.pdf>

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