Device Interface Board for Wireless LAN Testing Team May Client ECpE Department Faculty Advisor Dr. Weber Team Members Nathan Gibbs – EE Adnan Kapadia – EE Daniel Holmes – EE/CprE Kyle Peters – CprE April 27, 2005

Presentation Outline Project Overview –Introduction –Problem statement –Operating environment –Intended user(s) and use(s) –Assumptions and limitations –End product Project Activities –Present accomplishments –Future goals –Approaches considered and one used –Project definition activities –Research activities –Design –Test and implementation Resources and Schedule –Resource requirements –Schedule Closure Materials

Definitions DUT – Device under test (positive edge D flip-flop) Header – Preamble bits sent prior to the sending of information in a data packet Data packet – Group of bits sent through a communication channel sequentially FPGA – Field programmable gate array Tx/Rx – Transmitter/reciever time D3 D2 D1 D0 Data Packet Header voltage Figure 1 – Data Packet and Header

Project Overview

Acknowledgement Teradyne Dr. Weber –Advice –Carver Lab

Introduction Teradyne Integra J750 –Digital Tester –Donated to Iowa State Desire to test wireless chips using J750 Project is first step toward that goal Project created wireless interface to test digital device remotely Figure 2 – Teradyne Integra J750

Project Overview Problem Statement –Problem Prove J750 can perform wireless test on a device –Solution Develop wireless interface to J750 Develop test for DUT Solve latency and data transmission issues ? Figure 3 – Project Problem

Project Overview Operating Environment –27°C - 33°C –ESD wristbands –IG-XL for Windows Figure 4 – ESD Wristband

Project Overview Intended Users –ISU ECpE Faculty and Students Intended Uses –Functional test of a digital device –(Future) Wireless chipset test

Project Overview Assumptions –System Teradyne J750 can capture output despite delay introduced by wireless network –User Manual, or experience with J750 Experience with an FPGA and Verilog Understand the DUT operation Figure 5 – FPGAFigure 6 – D flip-flop circuit schematic

Project Overview Limitations –27°C - 33°C –Digital I/O only –Wireless components limit data rate –J750 cannot be moved –Rx/Tx range ~50 feet

Project Overview End Product and Other Deliverables –Wireless interface –Demonstration of wireless test –Manual for wireless test operation Figure 8 – Cover page of wireless manual

Project Activities

Project Definition –Initially wanted to test wireless chipset –Redefined project as “proof-of-concept” that J750 can wirelessly test a device

Project Activities Research Activities –Feasibility of testing wireless components with J750 –Researched J750 setup and test creation –Researched wireless system implementations

Project Activities Figure 9 – System Design Design

Project Activities Design Constraints –Limited choice of frequency channels –Lose speed from J750 – data rate of TX/RX at 115kbps –Limited to one FPGA

Project Activities Present Accomplishments –Wireless interface complete and tested –Demonstration complete –Manual of operation complete Figure 10 – Final Setup Figure 11 – Complete manual

Project Activities Approaches Considered –System Design 1.2 FPGA’s, 2 wireless transceivers 2.4 FPGA’s, 2 wireless transmitters, 2 receivers 3.1 FPGA’s, 2 wireless transmitters, 2 receivers, parallel to serial shift registers –Advantages/Disadvantages –Chose #3 Only 1 FPGA available Simple, but effective implementation Simple to recognize wireless packetsDedicated input and output data channels #1X #2XX #3X

Project Activities Implementation –Shift Register test on J750 –Milled and soldered Tx/Rx –Simulataed FPGA code –Implemented wired FPGA –Integrated subsystems Figure 12 – Mill used to create Tx/Rx

Project Activities Testing and Implementation –Tested each subsystem –Integrated subsystems into final setup –Testing form

Project Activities Figure 13 – Testing form Testing and Implementation

Resources and Schedule

Actual Resources Figure 14 -

Resources and Schedule ItemCost Project Poster$65.00 D Flip-Flop (TI- SN74LVC2G74)$ x 8-Bit Shift Registers (Fairchild 74F676)$ x Hex Schmitt Trigger (Fairchild MM74C14N )$1.80 Supplementary Circuit Components$45.00 Teradyne Integra J750 Test System$ Transmitter (RF Monolithics TX6000)$14.00 Transmitter (RF Monolithics TX6004)$14.00 Receiver (RF Monolithics RX6000)$20.00 Receiver (RF Monolithics RX6004)$ x 50 Ohm Antennas$2.00 PCB Milling$ FPGA$ Total Cost$502, Donated $ Other Resources Figure 15 - Resource Requirements {

Resources and Schedule ItemCost Parts$ Labor ($11/hour)$ Total$ Figure 16 – Project Costs with Labor

Resources and Schedule Figure 17 – Major project tasks schedule Figure 18 – Project Deliverables

Closing Material

Project Evaluation –SUCCESS –All subsystems work as planned –Final integrated system works Commercialization –Unlikely Cost Speed Immobile –Price - $200 to $1500 –RF companies

Closing Material Recommendations for Additional Work –Clock recovery circuit –Improve wireless data rate –Test wireless chips

Closing Material Lessons Learned –What technical knowledge was gained? Learned how to build and use wireless Tx/Rx FPGA implementation Teradyne Integra J750 usage Parallel ⇔ Serial conversion System integration

Closing Material Lessons Learned –What went well? System works! –What did not go well? Project definition Initial Teradyne J750 setup and test Improper daughterboard wiring Rx amplitude FPGA inputs

Closing Materials Anticipated Potential Risks –Teradyne Integra J750 and signal latency Encountered Risks –Internships –Receiver/Transmitter delivery delays –ESD to transmitter

Closing Materials Closing Summary –Problem –Solution –Successful implementation of solution

Figure 19 – Final System Setup

Output – Shift Register Figure 20 – Shift Register output

Output - Q Figure 21 – DUT output, Q

Output - Qbar Figure 22 – DUT output, Qbar

Output – Serialized Output Figure 23 – Reserialized output, 100 Q Qbar 001

Questions?

Thank You