ABSTRACTThe Civil Engineering department has set up a roof testing facility for simulatinghurricane-level winds. This facility employs 32 large 3-phase 208-Volt magnets toachieve the high levels of uplift force required. Individual magnets weighapproximately 250 pounds and draw up to 5KW. Each magnet has a dedicatedcontrol board, with a PIC microcontroller for management, and a serial eeprom forstoring the desired force response. Operator commands are communicated througha hierarchy of devices. A central command board sends operator commands tobeam control boards (magnets are suspended from large I-beams), which drive thecommand lines to the magnet control boards that control the magnet force. All threeboard types have a microcontroller and communicate though an optical-isolatornetwork, which allows only one-way communication. Presently, the four controllines only serve to regulate the magnet control board. For each magnet controlboard the eeprom has to be removed, programmed and reinstalled to tailor a newforce response. By adapting the existing command bus for loading magnet responsedata to memory (via the PIC microcontroller ), the danger of getting on the roofingstructure for updating the eeprom would be eliminated and the loading processwould be greatly simplified.

In this design project software must be developed for writing to the eeprom fromthe microcontroller and also must be developed for assuring correct data transferthough the optical isolation network. A hardware interface between the computerand the control circuitry must also be fabricated in compliance with the selectedsoftware for the transmission of the data, the selected data transfer method, and thechosen addressing scheme for the microcontroller and eeprom on each magnetcontrol board.

PROJECT GOAL

• Develop Hardware and Software for transmitting to EEPROM on MCB from PC

–Before Simulation–Existing One-way Comm.Bus

OBJECTIVES

• 1. BAUD RATE

• THE SYSTEM WILL OPERATE AT A MINIMUM OF 1200 BAUD.

• 2. SYSTEM CONTROL

• THE DATA TRANSMISSION SYSTEM WILL BE CONTROL VIA A PERSONAL COMPUTER.

• 3. SYSTEM OUTPUT• WIND RESPONSE DATA WILL BE TRANSMITTED TO THE EEPROM ON

THE MAGNET CONTROL BOARD

OBJECTIVES

• 4. HARD WARE• HARDWARE WILL BE DESIGNED FOR MAKING THE CONNECTION

FROM THE PC TO THE CONTROL CIRCUITRY

• 5. SOFTWARE• SOFTWARE WILL BE DEVELOPED TO INSURE PROPER DATA TRANSFER

AND THE ABILITY TO TRANSIT BETWEEN TRANSMIT AND WIND SIMULATION MODE.

• 6. POWER• THE SYSTEM WILL BE POWERED WITH PRESENT 208 3-PHASE POWER.

• 7. COST• INCREMENTSL HARDWARE COST WILL BE LESS THAN $600

Hardware Development

•CONTROL CIRCUITRY MODIFICATION

•INITIAL DATA TRANSFER TEST

Data Table 1.FREQ. P1 (uS) P2 (uS) P3 P4 P1-P2 (S)302HZ 0.0017 0.0014 24uS 240uS 2.20E-04

536.5HZ 940 716 24uS 240uS 2.24E+02709.7HZ 708 488 24uS 240uS 2.20E+02841.8HZ 592 380 24uS 240uS 2.12E+021004HZ 500 284 24uS 240uS 2.16E+021212HZ 412 192 24uS 240uS 2.20E+021502HZ 334 120 24uS 240uS 2.14E+021701HZ 294 78 24uS 240uS 2.16E+02

INPUT TRANSMIT TIMETESTING

P1

OUTPUT

P3P4 P2

Hardware Development

•Control Circuitry Modifications

•Testing

H 1 1 L 1 O PTO -C O UPL ER

PI C

P4

+ 1 5 V O L TS FR O MD C /D C C O NV ER TERO N B C B M A G N E T C O N T R O L B O A R D

T O R E L A Y S

TO M E M O R Y C H IPT-2 1

T -2 2 S IG N A L G O IN G T O M E M O R Y C H IP

F R O M P 3 O N B C B

Infra re dE m ittingD io de

+ 5

R 1

R 2

C E N T R A L C O N T R O L B O A R D

2 N2 2 2 2 A

+ 1 5 V O L TS FR O MD C /D C C O NV ER TER

4 N2 5 O PTO -C O UPL ER

O UTPUT FR O MPI C O N C C B

PI C

P1

TO P2 O N B C BR 3

T-1T-2

T-4

T-3

T-5 . . .G R D

Infra re dE m ittingD io de

P ho to -T ra ns is to rnpn

B E A M C O N T R O L B O A R D

H 1 1 L 1 O PTO -C O UPL ER

PI C

+ 5

R 4

R 5

+ 1 5 V O L TS FR O MD C /D C C O NV ER TER

4 N2 5 O PTO -C O UPL ER

R 6

P2

+ 1 5 V O L TS FR O MD C /D C C O NV ER TERO N C C B

P3

T-1 1T-1 2

T-1 3T-1 7 . .G R D

T-1 6

Infra re dE m ittingD io de

P ho to -T ra ns is to rnpn

Data Table 1.FREQ. P1 (uS) P2 (uS) P3 P4 P1-P2 (S)302HZ 0.0017 0.0014 24uS 240uS 2.20E-04

536.5HZ 940 716 24uS 240uS 2.24E+02709.7HZ 708 488 24uS 240uS 2.20E+02841.8HZ 592 380 24uS 240uS 2.12E+021004HZ 500 284 24uS 240uS 2.16E+021212HZ 412 192 24uS 240uS 2.20E+021502HZ 334 120 24uS 240uS 2.14E+021701HZ 294 78 24uS 240uS 2.16E+02

INPUT TRANSMIT TIMETESTING

P1

OUTPUT

P3P4 P2

TEST RESULTST-1 TO T-13 14uST-1 TO T-21 20uST-1 TO T-22 28us

PIC DELAY ~8us

FINAL SPEC.R1 (CCB) 22KR2 ( CCB) 15KR4 (BCB) POT.R5 (BCB) 15K

Hardware Development

•DATA Control Board Simulation

INITIAL DATA CONTROL BOARD

•Time Response–Optical Isolators

•Data Transfer Method–Software Dependant–One-Way Communication

•Protocol for Addressing–EEPROM

p in 1 2

p in 9

P in 8

P in 5

P in 6

P in s 1 0 ,1 3 ,1 8 - 2 5

2 5 P in S u b DC o n n ec to r P in s

S C L lin e

S D L lin e

+ 5 v o lts

1 3 1 2

1 0 1 1

6

1 21 3S C L _ O u t

S C L _ I n

S D L _ O u t

S D L _ I N

R 1 R 2R 3

R 4 R 5 R 6

R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 & R 8 = 1 0 K o h m s

R 7

R 8

R 9 = 2 2 0 o h m s

p in 1 2

p in 1 7

P in 1 5

P in 9

P in 1 1

P in s 1 0 ,1 3 ,1 8 - 2 5

2 5 P in S u b DC o n n ec to r P in s

S C L lin e

S D L lin e

+ 5 v o lts

1 3 1 2

1 0 11

6

2S C L_ O u t

S C L_ I n

S D L _ O u t

S D L _ I N

R 1 R 2R 3

R 4 R 5 R 6

R 1 , R 2 , R 3 , R 4 , R 5 , R 6 = 1 0 K o h m s

R 7 = 1 0 0 k

R 8 = 1 0 0 k

R 9 = 1 5 0 0 o h m s

R 1 0 = 1 5 0 0 o h m s

p in 1 2

p in 2

P in 3

P in 4

P in 5

P in s 1 0 ,1 3 ,1 8 - 2 5

C o n tr o l 1 lin e

C o n tr o l 2 lin e

+ 5 v o lts

C o n tr o l 1

F eed - b ac k 1

C o n tr o l 2

F eed - b ac k 2

R 1 1 R 1 2R 1 3

R 1 4 R 1 5 R 1 6

R 1 1 , R 1 2 , R 1 3 , R 1 4 , R 1 5 , R 1 6 = 1 0 K o h m s

R 1 7 = 1 0 0 k

R 1 8 = 1 0 0 k

R 1 9 = 1 5 0 0 o h m s

R 2 0 = 1 5 0 0 o h m s

1 2

1

1 3 1 2

6 7

1 0 11

34

9 8

N C

5

1

34

89N C

1 0 0 n F

1 0 0 n F

F inal D ata T ransmission B oard

Software Development

•Writing to EEPROM–I2C Data Transmission

– “DATA”

Software Development

• LABVIEW TO PIC MICROCONTOLER

• MIMICKED DATA TRANSFER TO EEPROM’S

• INTERFACE BETWEEN LABVIEW AND PIC

CONCLUSIONS• ALL HARDWARE DESIGN IS COMPLETE

• DATA TRANSMISION SOFTWARE FROM MICROCONTROLLER TO MEMORY CHIP IS COMPLETELY FUNCTIONAL

• MODE CONTROL AND ADDRESSING– TWO EXTRA CONTROL LINES

CONCLUSIONS• INTERFACE BETWEEN LABVIEW WILL BE COMPLETED POSSIBLE WITH ONLY SOME TIMING CHANGES

• OVERALL- DESIGN PROJECT WILL BE SUCCESFUL, WAS LIMITED ONLY BY TIME CONSTRAINS.

PROJECT COST• Hardware

– New Hardware ~$100

• Software

• ( $0) - Labview / C++

REFERENCES• [1] P. Horowitz, W. Windfield, The Art of Electronics, 2nd Ed,

Cambridge University Press, New York, New York, USA, 1971.

• [2] Texas Instruments, “Optoelectronics Data Book”, Texas Instruments Optoelectronics Data book, Texas Instruments Inc., Texas, USA, 1983

• [3] Microchip Technology, “MPLAB, IDE, SIMULATOR, EDITOR USER’S GUIDE”, Microchip Technology Inc., Arizona, USA, 1998

• [4] National Instruments, “Labview User Manuel”, National Instruments Corp. Texas, USA, 1992

REFERENCES• [5] Barry Press, PC Upgrade and Repair Bible, Professional

Edition, IDT Books Worldwide Inc., Foster CA, 1998

• [6] Microchip Technology Inc., “18-pin Enhanced Flash/EEprom 8-bit Microcontroller”, PIC16F84A Data Sheet, http://www.microchip.com/Download/Lit/PICmicro/16F8X/35007a.pdf, Arizona, USA, 1998

• [7] Microchip Technology Inc., “256 I^2C CMOS Serial EEPROM” 24AA256 Data Sheet, http://www.microchip.com/Download/Lit/Memory/ IC/64to128 /21203f.pdf, Arizona, USA, 2000

REFERENCES• [8] QT Optoelectronics, “Phototransistor Optocoupler,”

4N25 Optocoupler Data Sheet, http://www.webserver.qtopto.com/oi/4n2x.pdf, Sunnyvale,CA, USA, 2000

• [9] QT Optoelectronics, “Microprocessor Compatible GaAs Schmitt Trigger Optocouplers,” H11L1 Optocoupler Data Sheet, http://www.webserver.qtopto.com/ oi/h11l1.pdf,

Sunnyvale, CA, USA, 2000

REFERENCES• [10] Philips, “Application Notes and Development Tools

for 80C51 Microcontrollers,” Philips Semiconductors, Sunnyvale, CA, USA,1986

• [11] Business Direct Services, “what is I^2C,” I^2C Data Sheet,http://www.bdsltd.co.uk/teletext/i2c.htm, business Direct Services Limited,1999

EE4512 SENIOR DESIGN

MISSISSIPPI

STATE

UNIVERSITY ECE 4522 Tim Stults