mini project seminar

8/2/2019 Mini Project Seminar

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E QUIZ TABLEE QUIZ TABLE

Mini project seminar on


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Why should we go to electronic quiz table??????

Manual buzzers create a lot of confusion in identifying the first

respondent.

when two teams press the buzzer within a very small time gap,manualbuzzers cannot find the first respondent.

In manual buzzers, decision can be biased due to human intervention.

The circuits are also limited to only a few number of players.


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Microcontroller 89S51

LED display

Seven segment display


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AT89C51 is an 8-bit microcontrollerand belongs to Atmel's 8051 family.

AT89C51 has 4KB of Flash programmable and erasable read only memory

(PEROM) and 128 bytes of RAM.

It can be erased and program to a maximum of 1000 times.

In this project, port 1 is assigned as input port and port 0 and port2 are

assigned as output port.
http://www.engineersgarage.com/microcontrollerhttp://www.engineersgarage.com/8051-microcontrollerhttp://www.engineersgarage.com/8051-microcontrollerhttp://www.engineersgarage.com/microcontrollerhttp://www.engineersgarage.com/microcontroller


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A seven segment display is the most basic electronic display device

that can display digits from 0-9.

A seven segment is generally available in ten pin package.

While eight pins correspond to the eight LEDs, the remaining two pins

(at middle) are common and internally shorted.

Seven LEDs 'a' to 'g' are used to display the numerals while eighth LED

'h' is used to display the dot/decimal.


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LEDS LEDs are formed from various doped semiconductor materials in theform of a P-N diode junction.

When electrical current passes through the junction in the forwarddirection, the electrical carriers give up energy proportional to theforward voltage drop across the diode junction, which is emitted in theform of light.

ADVANTAGES:low power consumption

low self- heating

high reliability

They can be switched on and offquickly

They are resistant to shock andvibration


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Transistor BC548

BC548 is general purpose silicon, NPN, bipolar junction transistor.

It is used for amplification and switching purposes.

The current gain may vary between 110 and 800.

The maximum DC current gain is 800.

BC548 is used in common emitter configuration for amplifiers.


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7805 voltage regulator:

The 7805 voltage regulators employ built-in current

limiting, thermal shutdown, and safe-operating area

protection which make them virtually immune to

damage from output overloads.

7805 is a three-terminal positive voltage regulator.

With adequate heat sinking, it can deliver in excess of

0.5A output current.

It looks like a transistor but it is actually anintegrated circuit with legs.

It can take a higher, crappy DC voltage and turn it

into a nice, smooth 5 volts DC.


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This quiz buzzer system has eight input pins corresponding to eight teams.

The output is displayed on a seven segment display, which shows the

number corresponding to the team which has pressed the button first.

A buzzer is also sounded for a small duration to give an acoustic alarm.
http://engineersgarage.com/content/seven-segment-displayhttp://engineersgarage.com/content/seven-segment-display


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SOURCE CODE

p2.0 RLY1

p2.1 RLY2p2.2 RLY3

p2.3 RLY4

p2.4 RLY5

p2.3 RLY6

p2.3 RLY7

p2.3 RLY8

p1.0 SW1

p1.1 SW2

p1.2 SW3

p1.3 SW4

p1.4 SW5p1.5 SW6

p1.6 SW7

p1.7 SW8

p3.1 RESET

P0.0-0.3=DISP247


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org 0000h

nop

ajmp begin

org 000bhljmp int

org 0050h

begin: mov sp,#60h

mov tcon,#00h

mov ie,#00h

mov p0,#00h

mov p2,#00h

mov psw,#00h

mov p1,#0ffh

setb p3.1

mov 30h,#00h


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start:

mov a,30h

cjne a,#00h,res

setb p1.0jb p1.0,go1

mov p2,#01h

clr p3.7

mov p0,#01h

ljmp last

res: ljmp reset1go1: setb p1.1

jb p1.1,go2

mov p2,#02h

mov p0,#02h

clr p3.7

ljmp last


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go2: setb p1.2

jb p1.2,go3

mov p2,#04h

clr p3.7mov p0,#03h

ljmp last

go3: setb p1.3

jb p1.3,go4

mov p2,#08h

clr p3.7mov p0,#04h

ljmp last

go4: setb p1.4

jb p1.4,go5

mov p2,#10h

clr p3.7

mov p0,#05h

ljmp last


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go5: setb p1.5

jb p1.5,go6

mov p2,#20h

clr p3.7

mov p0,#06h

ljmp last

go6: setb p1.6

jb p1.6,go7

mov p2,#40h

clr p3.7

mov p0,#07h

ljmp last

go7: setb p1.7

jb p1.7,go8

mov p2,#80hclr p3.7

mov p0,#08h

ljmp last


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go8: mov p2,#00h

setb p3.7

mov p0,#09h

ljmp lastlast: mov 30h,#55h

reset1: setb p3.1

jb p3.1,reset1

lcall dly

setb p3.1

jb p3.1,reset1

mov 0,#00h

mov p2,#00h

clr p3.7

mov 30h,#00h

ljmp startdly: mov psw,#00h

mov r0,#90h

dly1: djnz r0,dly1

ret

end


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