Moving Message Display System

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Moving Message Display

INTRODUCTION

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1. INTRODUCTION

Todays publicity trends are involving with novel methods. The presentation part plays

vital role for publicity. So there are different methods to display the presentations are developing

like direct printing of images on hoardings using cloth, neon display systems, rolling screens

electronic display systems etc. out of all, electronic display systems are dominating in

presentation of advertisements.

or small message presentations this rolling display sign boards are very effective than

any other display systems. These are compact and economical for general applications. !olling

Displays are ideal for all type of commercial establishments like "otels, !estaurants, #anks,

$irports, and other such places to get ma%imum attention of people where vast amounts of

information need to be conveyed to large audiences both &uickly and efficiently, also in the

world of indoor and outdoor displays.

These displays attract customers to watch the display with curiosity and your scrolling

Message also is conveyed simultaneously. 'ery good advertising results are obtained from these

(ni&ue displays with latest technology.

This )ro*ect +) #ased !olling Display Sign #oard using Micro ontroller- basically

depends upon the micro controller and its software. There should be standard ) eyboard to

input to the message to be displayed. /ou can change the message as often as you want your self

with ordinary computer keyboard without any prior e%perience of any kind.

The display unit should be able to display at least 0 characters at a time. The total

message may be taken as ma%imum 0 characters. There should be provision for shifting of data

from !ight to 2eft. 3ach character re&uires 4 % 4 matri% display. So 50 23Ds are re&uired for the

displaying one character. Therefore total 675 23Ds are re&uired for displaying 0 characters at a

time.

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INTRODUCTION TO

EMBEDDED SYSTEMS

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2. INTRODUCTION TO EMBEDDED SYSTEMS

2.1 Definition

$ combination of hardware and software, which together form a component of a larger

machine. $n e%ample of an embedded system is a microprocessor that controls an moving

message display. $n embedded system is designed to run its own without human intervention,

and may be re&uired to respond to events in real time.

$ speciali9ed computer system that is part of a large system or machines typically, an

embedded system is housed on a single microprocessor board with the program stored in !:M.

'irtually all appliances that have a digital interface ;watches, microwaves and '!s utili9e

embedded systems. Some embedded systems include an operating system, but many are so

speciali9ed that the entire logic can be implemented as a single program.

3ach day, our lives become more dependent on !:M, loppy Disk.

3mbedded systems have to operate in e%treme environmental conditions such as very

high temperatures and humidity.

2." #pp$i%ation #reas of Embee S!stems

onsumer $ppliances

:ffice $utomation

Medical 3lectronics

$dvertisement

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&OR'IN( )RINCI)*E

OF MO+IN( MESS#(E

DIS)*#Y

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". &OR'IN( )RINCI)*E OF MO+IN( MESS#(E

DIS)*#Y

The )rinciple of :peration of the +) #$S3D !:22?@= D?S)2$/ S?=@ #:$!D (S?@=

M?!: :@T!:223!- is mainly depends upon the following two functions.

AiB Serial interface between the 15 decoders.

AiB Chat ever the message is to be displayed is given to the ) through standard )

keyboard. The message to displayed is only of 3nglish capital letters and numerical

from to . This message is transferred to the micro controller from the ) by using

!S>686 serial communication in the form of $S?? code for the corresponding letter

typed in pc. The message typed in the pc with the keyboard is converted to $S??

with the help of program. The #aud !ate used for the serial communication here is

,5 bps.

,ii- The corresponding $S?? code for the character typed is transferred to micro>

controller through the level converter AM$E>686B. The micro>controller reads the

corresponding letter typed with the help of !ED pin. The program for selecting the

rows and columns is written in the assembly language is stored in micro>controller

itself.

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DESI(N )ROCEDURE

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. DESI(N )ROCEDURE

The design of any pro*ect is a step by step method. The design involves some basic steps

They are

ircuit design

)# design

hecking the components

?nstalling the components into )#

Testing

.1 Cir%uit Desi/n

The circuit design is the main step in design of the any pro*ect. ?n designing of the circuit

we should have to know the characteristic of the each and every component. The circuit design

can be done in the chart or in any circuit editor. ?n this pro*ect first D# female is connected to

the Transmitter through M$E686. "ere M$E686 is the voltage level converter from TT2 toM:S levels. "ere totally the components re&uire at the transmitter side are D# female,

M$E686 and the transmitter.

The receiver is connected to the microcontroller. The microcontroller is connected to the

decoders and latches for driving the columns and rows of the display to represent the character.

.2 )CB Desi/n)# design is done in G(3@ $DST$!. G(3@ $DST$! is the software used for

designing of the )#. ?n this software first we design the circuit diagram. $fter words

corresponding )# layout is designed. The )# layout is compiled in that software if any

errors are came that errors are display in the dialog bo% that errors shows any short circuits in

the )#. $fter designing the )# layout the layout is printed on the circuit board. The

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dimensions of board and printing level decide the cost of )#. $fter designing the )# we

should have to check out all connections in the )#.

The )# layouts of the transmitter and receiver are given as bellow

Transmitter

ig 0.1 )# layout for transmitter section


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Re%ei0er

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ig 0.6 )# layout of receiver section

." Ce%in/ te Components

Different components are checked in different ways. Transistors are checked by

checking the hfeof transistor. The hfe value should be above of 67. The capacitors are

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checked by the multimeter. !esistors and connections in the )# are also checked by

multimeter. ?S are checked out by the ? tester.

. Insta$$in/ te Components Into )CB

?n installing the components we should have to take care about the soldering. Temperature is

the main thing in soldering. ?S, capacitors, regulators and resistors are very sensitive to the

temperature. So ? bases are used for the ?s. ?n soldering of ad*acent pins of ? or connectors

are not to be shorted.

.3 Testin/

Testing of the designed )# is the crucial thing. The testing can be done in different

ways. The testing of power supply can be done in first step. Testing of the transmitter and

receiver is done in second step by connecting the function generators output to transmitter and

checking the out put of the receiver in !:. $fter that the whole circuit is tested by giving the

input to M and checking the output at the display. or checking the display, multimeter is kept

in supply mode. #y placing positive terminal at row AanodeB pins and negative terminal at

columns AcathodeB corresponding 23Ds are tested.

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B*OC' DI#(R#M

3. B*OC' DI#(R#M

3.1 Transmitter B$o% Dia/ram

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ig 7.1

3.2 Re%ei0er B$o% Dia/ram

ig 7.6

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CIRCUIT DI#(R#M

#NDO)ER#TION

4. CIRCUIT DI#(R#M #ND O)ER#TION

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4.1 Transmitter Dia/ram an its Operation

ig 5.1

To display message in the display board we need to compile the above c program in

standard compilers. $fter the compilation the program asks to input the data that is to be

displayed. The input data to be started with star AHB and ends with the same. The ) transmits the

data through the !S686 to transmitter. $s we have to convert the !S686 logic levels to M:S

logics we use M$E686 in middle of them. The data to be transmitted is modulated by ::

modulation at 088 M"G fre&uency and transmitted as analog signal by the transmitter.

4.2 Re%ei0er Dia/ram an its Operation

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The 088 M"G fre&uency analog signal is received by the receiver. The receiver demodulates and

converts it to obtain the original data. The output from the receiver is connected to the pin1

A!EDB of microcontroller A$T471B.$ reset circuit is connected to pin A!STB of M. The

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11.76M"G crystal is connected to pin14 AET$26B and pin1 AET$21B of M as shown in the

above figure.

The port A). to ).FB is connected to latch AF02S7F8B input pins 6 to . The pin1 of

latch is connected to ground and pin 11 to pin 6F A3$B of M to enable the latch. The pin61 to

60 A)6. to )6.8B of M is connected to decoder input pins A68 to 6B respectively to 6 decoders

AF0"170B. )in 67 of M is connected to decoder A1B and )in 65 of M is connected to decoder

A6B to pin 14 to enable the decoder. The pin1 A31B and pin16 A=@DB of decoder are grounded,

for the operation of decoder pin 1 should be always low.

The latch outputs are connected to the rows of the display. The decoder outputs are

connected to columns of display. The bits corresponding to the given character is transmitted to

the latch and it transfers to the corresponding rows. The columns are refreshed by the decoders at

17Is so that the data appears to be moving from right to left.

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)O&ER SU))*Y

5. )O&ER SU))*Y

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Most digital logic circuits and processors need a 7 volt power supply. To use these parts

we need to build a regulated 7 volt source. To make a 7 volt power supply, we use a 2MF47

voltage regulator ?. The ? is shown below.

The 2MF47 is simple to use. /ou simply connect the positive lead of your unregulated

D power supply Aanything from 'D to 60'DB to the ?nput pin, connect the negative lead to

the ommon pin and then when you turn on the power, you get a 7 volt supply from the :utput

pin.

Sometimes the input supply line may be noisy. To help smooth out this noise and get a

better 7 volt output, a capacitor is usually added to the circuit, going between the 7 volt outputand ground A=@DB. Ce use a 66 u capacitor.

5.1 +O*T#(E RE(U*#TORS6

$ 'oltage !egulator has only three legs and appears to be a comparatively simple device

but it is actually a very comple% integrated circuit. $ regulator converts varying input voltage and

produces a constant JregulatedJ output voltage. 'oltage regulators are available in a variety of

outputs, typically > 7 volts, volts and 16 volts. The last two digits in the name indicate theoutput voltage.

The J2MF4EEJ series of voltage regulators are designed for positive input. or

applications re&uiring negative input the J2MFEEJ series is used.

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ig F.1

The circuit diagram below represents a typical use of a voltage regulator.

ig F.6

The transformer drops 60 volt KmainsK voltage to volts. The diode KbridgeK changes the

4.7 volts $ into D. The 1u capacitor helps to maintain a constant input into the regulator.

$s a general guide this capacitor should be rated at a minimum of 1u for each amp of

current drawn and at least TC?3 the input voltage. The .1u capacitor eliminates any high

fre&uency pulses that could otherwise interfere with the operation of the regulator.

'oltage regulators are very robust. They can withstand over>current draw due to short

circuits and also over>heating. ?n both cases the regulator will shut down before damage occurs.

The only way to destroy a regulator is to apply reverse voltage to its input. !everse polarity

destroys the regulator almost instantly. To avoid this possibility you should always use diode

protection of the power supply. This is especially important when using nine volt battery supplies

as it is common for people to KtestK the battery by connecting it one way and then the other. 3ven

this short KtestK would destroy the regulator if a protection diode were not used.

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$ll of the interfaces described on this site have protection diodes for this reason. (sually

a 1@0F, 1 amp power diode is connected in series with the power supply.

F.6 ?nput voltageL

$s a general rule the input voltage should be limited to 6 to 8 volts above the output

voltage. The 2MF4EE series can handle up to 8 volts input, but the power difference between

the input voltagecurrent ratio and output voltagecurrent ratio appears as heat. ?f the input

voltage is unnecessarily high the regulator will get very hot. (nless sufficient heat>sinking is

provided the regulator will shut down.

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SERI#*

COMMUNIC#TION

7. SERI#* COMMUNIC#TION

7.1 )ersona$ Computer6

)ersonal computer is a general purpose computer. This is having the D# male port to

connect to the e%ternal devices. ?n this pro*ect compiler is necessary for transmitting the data

through the D# port. $ key board is re&uired to input the data in to ). The eyboard must

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accommodate all 65 3nglish $lphabets along with numerical keys and a space bar. or editing

purpose two cursor control keys namely left A B and right AB are re&uired along with a

control key. inally andH key would be re&uired to initiate the rolling the mechanism of the

display. or all above functions we have used the standard keyboard of 14 keys, i.e. normally

used for the computer.

7.2 RS2"2 )ort6

The most common serial interface used today by computer manufacturers is the !S>686.

This serial interface found on practically every ) and e%ternal modem Aand many other

devicesB. !S>686 is simple, universal, well understood and supported everywhere. The original

!S>686 standard only specified the data speeds up to 16 bps. The output signal level usually

swings between N16v and >16v. ?n this anything higher than N8' is considered to be logic and

anything lower than >8' is considered to be logic 1. The Jdead areaJ between N8v and >8v is

designed to absorb line noise.

ig 4.1

The above shown connector known as >pin, D>type male connector is used for !S686

connections. The pin description is given in the following table.

)in number ommon

@ame

!S686 nameDescription Signal direction

1 D !eceived line signal detector ?@

6 !ED ## !eceived data ?@

1

12

3

4

56

7

8

9

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8 TED #$ Transmitted data :(T

0 DT! D Data terminal ready :(T

7 =@D $# Signal ground >>

5 DS! Data set ready ?@

F !TS $ !e&uest to send :(T

4 TS # lear to send ?@ >> 3 !ing indicator ?@

Table 4.1.

ig 4.6

Ce cannot simply connect our system to this terminal with out providing proper hand

shaking signal. or communicating with !S>686 type e&uipment, the !TS of the connector is

simply looped into the TS, so TS will automatically be asserted when !TS is asserted

internally. Similarly the DT! is looped into DS! and D, so when ) asserts its DT! output

the DS! and D inputs are automatically be asserted. These connections do not provide for any

hardware hand shaking. They are necessary to get the ) and our system talk each other.

7." M#8 2"26

The $T471 microcontroller is based on M:S logic. M:S logic levels are logic

for .1 to 1' and logic 1 for 8.7 to 7'. #ut as mentioned above in !S686 the logic levels are &uit

reverse to M:S levels. So to convert the !S686 logic levels to M:S levels we have use

M$E686.

1

12

3

4

56

7

8

9

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The original M$E686 is a 15 pin ? with dual in line package and it includes two drivers

that convert TT2 inputs to !S>686 outputs, and two receivers that accept !S>686 inputs and

translate them to M:S>compatible outputs.

The difference between TT2 and M:S logic levels as fallows

)arameter TT2 logic AvoltsB M:S logicAvoltsB F0"T AvoltsB

2ogic>low output

Ama%imumB

.0 .1 .1

2ogic>high output

AminimumB

6.0 8.7 8.7

2ogic>low input

Ama%imumB

.4 1 .4

2ogic>high input

AminimumB

6. 8.7 6.

Table 7.6

The pin description and internal blocks of the M$E686is given below as diagram

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ig 4.8 ig 4.0

our e%ternal capacitors store energy for the supplies. The recommended value for the

capacitors is 1 or larger.

The capacitors in M$E686 are connected as fallows

The 0 e%ternal 1u capacitors are used by the internal charge pump to create N1' and >1'

or the first capacitor, the negative leg goes to pin 8 and the positive leg goes to pin 1.

or the second capacitor, the negative leg goes to pin 7 and the positive leg goes to pin 0.

or the third capacitor, the negative leg goes to 7 volts and the positive leg goes to pin 6.

or the fourth capacitor, the negative leg goes to pin 5 and the positive leg goes to ground.

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RF *IN'

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9. RF *IN'

or different application we are using different fre&uency for transmitting the data. #ut in this

pro*ect we are using 088 M"9 fre&uency because it is the license free 9one.

The ! link consists of

! Transmitter ASTT 088B

! !eceiver AST! 088B

9.1 RF TR#NSMITTER6

The transmitter used is STT>088 ASunrom Technologies TransmitterB. The STT>

088 is ideal for remote control applications where low cost and longer range is re&uired.

The transmitter operates from a 1.7>16' supply, making it ideal for battery>powered

applications. The transmitter employs a S$C>stabili9ed oscillator, ensuring accurate

fre&uency control for best range performance. :utput power and harmonic emissions areeasy to control, making and 3TS? compliance easy. The manufacturing>friendly S?)

style package and low>cost make the STT>088 suitable for high volume applications.

9.1.1 Features

088.6 M"9 re&uency

2ow ost

1.7>16' operation

11m$ current consumption at 8'

Small si9e

0 d#m output power at 8'

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9.1.2 #pp$i%ations ig .1

!emote eyless 3ntry A!3B

!emote 2ighting ontrols

:n>Site )aging

$sset Tracking

Cireless $larm and Security Systems

2ong !ange !?D

$utomated !esource Management

9.1." )in Des%ription

)in @ame Description

$@T

7 ohm antenna output. The antenna port impedance affects output power

and harmonic emissions. $n 2> low>pass filter may be needed to

sufficiently filter harmonic emissions. $ntenna can be single core wire of

appro%imately 1Fcm length or )# trace antenna

'

:perating voltage for the transmitter. ' should be bypassed with a .

1u ceramic capacitor and filtered with a 0.Fu tantalum capacitor. @oise

on the power supply will degrade transmitter noise performance.

D$T$

Digital data input. This input is M:S compatible and should be driven

with M:S level inputs.

=@D Transmitter ground. onnect to ground plane.

Table 9.1Pin Name Description

9.1. O)ER#TION

:: A:n :ff eyingB modulation is a binary form of amplitude modulation.

Chen a logical Adata line lowB is being sent, the transmitter is off, fully suppressing thecarrier. ?n this state, the transmitter current is very low, less than 1m$. Chen a logical 1

is being sent, the carrier is fully on. ?n this state, the module current consumption is at its

highest, about 11m$ with a 8' power supply.

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:: is the modulation method of choice for remote control applications where

power consumption and cost are the primary factors. #ecause :: transmitters draw no

power when they transmit a , they e%hibit significantly better power consumption than

S transmitters. :: data rate is limited by the start>up time of the oscillator. "igh>O

oscillators which have very stable center fre&uencies take longer to start>up than low>O

oscillators. The start>up time of the oscillator determines the ma%imum data rate that the

transmitter can send.

9.1.3 Data Rate

The oscillator start>up time is on the order of 0uSec, which limits the ma%imum

data rate to 0.4 bitsec.

9.1.4 Sa: Stabi$i;e Os%i$$ator

The transmitter is basically a negative resistance 2 oscillator whose center

fre&uency is tightly controlled by a S$C resonator. S$C ASurface $coustic CaveB

resonators are fundamental fre&uency devices that resonate at fre&uencies much higher

than crystals.

9.2 RF RECEI+ER

The ST!>088ASunrom Technologies !eceiverB is ideal for short>range remote

control applications where cost is a primary concern. The receiver module re&uires no

e%ternal ! components e%cept for the antenna. ?t generates virtually no emissions,

making and 3TS? approvals easy. The

Super>regenerative design e%hibits e%ceptional sensitivity at a very low cost. The

manufacturing>friendly S?) style package and low>cost make the ST!>088 suitable forhigh volume applications.

9.2.1 Features

2ow ost

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7' operation

8.7m$ current drain

@o 3%ternal )arts are re&uired

!eceiver re&uencyL 088.6 M"G Typical sensitivityL >17d#m

? re&uencyL 1M"9

9.2.2 #pp$i%ations

ar security system

Sensor reporting

$utomation system ig 5.6

!emote eyless 3ntry A!3B

!emote 2ighting ontrols

:n>Site )aging

$sset Tracking

Cireless $larm and Security Systems

2ong !ange !?D

$utomated !esource Management

9."." )in Des%ription6

)in Name Description

$@T $ntenna input.

=@D =@D !eceiver =round. onnect to ground plane

'A7'B

' pins are electrically connected and provide operating voltage for

the receiver. ' can be applied to either or both. ' should be

bypassed with a .1I ceramic capacitor. @oise on the power supply willdegrade receiver sensitivity.

D$T$Digital data output. This output is capable of driving one TT2 or

M:S load. ?t is a M:S compatible output.

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Table 6.2

9.2. Operation of te Re%ei0er

9.2..1 Super088 uses a super>regenerative $M detector to demodulate the incoming

$M carrier. $ super regenerative detector is a gain stage with positive feedback greater

than unity so that it oscillates. $n !>time constant is included in the gain stage so that

when the gain stage oscillates, the gain will be lowered over time proportional to the !

time constant until the oscillation eventually dies. Chen the oscillation dies, the current

draw of the gain stage decreases, charging the ! circuit, increasing the gain, and

ultimately the oscillation starts again.

?n this way, the oscillation of the gain stage is turned on and off at a rate set by

the ! time constant. This rate is chosen to be super>audible but much lower than the

main oscillation rate. Detection is accomplished by measuring the emitter current of the

gain stage. $ny ! input signal at the fre&uency of the main oscillation will aid the mainoscillation in restarting. ?f the amplitude of the ! input increases, the main oscillation

will stay on for a longer period of time, and the emitter current will be higher. Therefore,

we can detect the original base>band signal by simply low>pass filtering the emitter

current. The average emitter current is not very linear as a function of the ! input level.

?t e%hibits a 1ln response because of the e%ponentially rising nature of oscillator start>up.

The steep slope of a logarithm near 9ero results in high sensitivity to small input signals.

9.2..2 Data S$i%er

The data slicer converts the base>band analog signal from the super>regenerative

detector to a M:STT2 compatible output. #ecause the data slicer is $ coupled to the

audio output, there is a minimum data rate. $ coupling also limits the minimum and

ma%imum pulse width. Typically, data is encoded on the transmit side using pulse>width

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modulation A)CMB or non>return>to>9ero A@!GB. The most common source for @!G data

is from a ($!T embedded in a micro>controller. $pplications that use @!G data

encoding typically involve microcontrollers.

The most common source for )CM data is from a remote control ? such as the

">163 from "oltek or ST10 :D3 from Sunrom Technologies. Data is sent as a

constant rate s&uare>wave. The duty cycle of that s&uare wave will generally be either

88P Aa 9eroB or 55P Aa oneB. The data slicer on the ST!>088 is optimi9ed for use with

)CM encoded data, though it will work with @!G data if certain encoding rules are

followed.

9.2.." )o:er Supp$!

The ST!>088 is designed to operate from a 7' power supply. ?t is crucial that this

power supply be very &uiet. The power supply should be bypassed using a .1u low>

3S! ceramic capacitor and a 0.Fu tantalum capacitor. These capacitors should be placed

as close to the power pins as possible. The ST!> 088 is designed for continuous duty

operation. rom the time power is applied, it can take up to F7mSec for the data output

to become valid.

9.2..#ntenna Input

?t will support most antenna types, including printed antennas integrated directly

onto the )# and simple single core wire of about 1Fcm. The performance of the

different antennas varies. $ny time a trace is longer than 14th the wavelength of the

fre&uency it is carrying, it should be a 7 ohm microstrip.

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MICROCONTRO**ER

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1=. MICROCONTRO**ER

1=.1 INTRODUCTION

2ooking back into the history of microcomputers, one would at first come across the

development of microprocessor, but the stand alone microprocessor is not self>sufficient.

?t re&uires other components like memory and ?: devices to form a workable system

configuration. The device which contains a microprocessor and the above mentioned

components is a microcontroller. The introduction of microcontrollers drastically changed the

microprocessor based system design. The earlier versions of ?ntels microcontrollers 481 and

471 do not have on>chip 3)!:M and lock bit protection modes. So we are using $T471

microcontroller in our pro*ect.

The $T471 is a low>power, high>performance M:S 4>bit microcomputer with 0

bytes of lash programmable and erasable read only memory A)3!:MB. The device is

manufactured using $tmels high>density nonvolatile memory technology and is compatible with

the industry>standard MS>71 instruction set and pin out. The on>chip lash allows the programmemory to be reprogrammed to the ?. #y combining a versatile 4>bit )( with lash on a

monolithic chip, the $tmel $T471 is a powerful microcomputer which provides a highly>

fle%ible and cost>effective solution to many embedded control applications.

The $T471 provides for 0k 3)!:M!:M, 164 byte !$M and 86 ?: lines. ?t also

includes a universal asynchronous receive>transmit A($!TB device, two 15>bit timercounters

and elaborate interrupt logic. 2ack of multiply and divide instructions which had been always

felt in 4>bit microprocessorsmicro controllers, has also been taken care of in the 471> Thus

the 471 may be called nearly e&uivalent of the following devices on a single chipL 447 N

4677 N 4671 N 4678 N 6F50 N 5115.

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1=.2 FE#TURES

?n short, the $T471 has the following on>chip facilitiesL

0k !:M A3)!:M on 4F71B

164 byte !$M

($!T

86 input>output port lines

Two, 15>bit timercounters

Si% interrupt sources and

:n>chip clock oscillator and power on reset circuitry

1=." )IN DI#(R#M

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ig 1.1

1=. #RC>ITECTURE

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ig 1.6

1=.3 SI*ENT FE#TURES

The 471 can be configured to bypass, the internal 0k !:M and run solely with

e%ternal program memory. or this its e%ternal access A3$B pin has to be grounded. The program

store enable A)S3@B signal acts as read pulse for program memory. The data memory is e%ternal

only and a separate !DH signal is available for reading its contents.

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(se of e%ternal memory re&uires that three of its 4>bit ports Aout of fourB are configured

to provide dataaddress multiple%ed bus. "i address bus and control signals related to e%ternal

memory use. The !ED and TED ports of ($!T also appear on pins 1 and 11 of 471 and

481, respectively. :ne 4 bit port, which is bit addressable and, e%tremely useful for control

applications.

The ($!T utilises one of the internal timers for generation of baud rate. The crystal used

for generation of )( clock has therefore to be chosen carefully. The 11.75 M"9 crystalsQ

available abundantly, can provide a baud rate of 5.

1=.4 CENTR#* )ROCESSIN( UNIT

2et add 8 more memory locations to a specific block that will have a built in capability to

multiply, divide, subtract, and move its contents from one memory location onto another. The

part we *ust added in is called +central processing unit- A)(B. ?ts memory locations are called

registers.

!egisters are therefore memory locations whose role is to help with performing various

mathematical operations or any other operations with data wherever data can be found. 2ook at

the current situation. Ce have two independent entities Amemory and )(B, which areinterconnected, and thus any e%change of data is hindered, as well as its functionality. ?f, for

e%ample, we wish to add the contents of two memory locations and return the result again back

to memory, we would need a connection between memory and )(. Simply stated, we must

have some +way- through data goes from one block to another.

The term used in micro controller isL

1=.5 MEMORY UNIT

Memory is part of the micro controller whose function is to store data. The easiest way

to e%plain it is to describe it as one big closet with lots of drawers. ?f we suppose that we marked

the drawers in such a way that they can not be confused, any of their contents will then be easily

0


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accessible. ?t is enough to know the designation of the drawer and so its contents will be known

to us for sure.

Memory components are e%actly like that. or a certain input we get the contents of a

certain addressed memory location and thats all. Two new concepts are brought to usL

addressing and memory location. Memory consists of all memory locations, and addressing is

nothing but selecting one of them. This means that we need to select the desired memory location

on one hand, and on the other hand we need to wait for the contents of that location. #esides

reading from a memory location, memory must also provide for writing onto it. This is done by

supplying an additional line, called control line. Ce will designate this line as !C AreadwriteB.

ontrol line is used in the following wayL if rwR1, reading is done, and if opposite is true then

writing is done on the memory location. Memory is the first element, and we need a

few operation of our micro controller.

The 675 byte address space is utili9ed by the internal !$M and special function registers

AS!sB array which is separate from e%ternal data !$M space of 50k. The >F space is

occupied by the !$M and the 4 > space by the S!s. The 164 byte internal !$M has been

utili9ed in the following fashionL

>?L (sed for four banks of eight registers of 4>bit each. The four banks may be selected by

software any time during the program.

6>6L The 15 bytes may be used as 164 bits of individually addressable locations. These are

e%tremely useful for bit oriented programs.

127 b!tes

R#M

"2 B!tes

Re/ister Se$e%tor

Ban

14 B!tes

#ressin/

#rea

7= B!tes

(enera$ )urpose

RB= RB1 RB2 RB"

01


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8> FL This area is used for temporary storage, pointers and stack. :n reset, the stack starts at 4

and gets incremented during use.

1=.5.1 Basi% Re/isters6

#%%umu$atorL

06


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The accumulator, as its name suggests, is used as a general register to accumulate the

results of a large no of instructions. ?t can hold an 4>bit A1>byteB value and is the most versatile

register.

?R@ re/ister6

The ! registers are a set of 4 registers that are !, !1.!F. These registers are used as

au%iliary registers in many operations.

?B@ re/isters6

The # register is very similar to the accumulator in the sense that it may hold an 4>bit

value. The # register is only used by two 471 instructionsL M(2 $# and D?' $#. Thus, if u

want to &uickly and easily multiply or divide $ by another number, u may store the number in #

register and make use of these two instructions.

)ro/ram Counter ,)C-6

The program counter is a 6>byte addressQ it tells the 471 where the ne%t instruction

e%ecutes is found in memory. Chen the 471 is initiali9ed ) always starts at " and is

incremented each time an instruction is e%ecuted.

Data )ointer ,D)TR-6

The data pointer is the 471s only user accessible 15>bit register. The accumulator, !

register and # register are all 1byte registers. D)T!, as the name suggests, is used to point to

data. ?t is used by a no of commands, which allows the 471 to access e%ternal memory. Chen

the 471 access e%ternal memory it will access e%ternal memory at the address indicated by

D)T!.

Sta% )ointer ,S)-6

The stack pointer, like all registers e%cept D)T! and ), may hold an 4>bit value. The S)

is used to indicate where the ne%t value to be removed from the stack. Chen you push a value

on to the stack, the 471 first increments the value of stack pointer and then stores the value at

the resulting memory location. Chen you pop a value of the stack, the 471 returns the value

from the memory location indicated by S), and then decrements the value of S). The S) is

modified directly by the 471 by 5 instructionsL )(S", ):), $$22, 2$22, !3S3T and

!3T?.

1=.5.2 Spe%ia$ Fun%tion Re/isters6

08


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The 471 is a fle%ible microcontroller with a relative large no of modes of operations.

S!s are accessed as if they were normal internal !$M. 3ach S! has an address A4" through

"B and a name. The following table provides 471s S!s, their names and their address.

#r. )ortARe/ister

4 ) A)ort B

41 S) Astack pointerB

46 D)" Adata pointer "ighB

48 D)2 Adata pointer 2owB

44 T:@ Atimer controlB

4 TM:D Atimer modeB

4$ T2: Atimer low byteB

4# T21 Atimer 1 low byteB

4 T" Atimer high byteB

4D T"1 Atimer 1 high byteB

)1 Aport 1B4 S:@ Aserial controlB

S#( Aserial bufferB

$ )6 Aport 6B

$4 ?nterrupt enable A?3B

# )8 Aport 8B

#4 ?nterrupt priority A?)B

D )rocessor status word A)SCB

3 $ccumulator A$B

# register

Table 1.1

Des%ription6

)= ,)ort = #ress 7= Bit-6

This is the stack pointer of the microcontroller. This S! indicates where the ne%t value

to be taken from the stack will read from in internal !$M. ?f you push a value on to stack, the

value will be written to the address of S)N1. That is to say, if S) holds the value F", a push

instruction will push the value on to the stack at the address 4". This S! is modified by all

00


45/109


instructions, which modify the stack, such a )(S", ):), 2$22, !3T, !3T? and whenever

interrupts are provoked by the microcontroller.

D)*A D)> ,Data )ointer *o:A>i/ #resses 72A7"-6

The S!s D)2 and D)" work together to represent a15>bit value called the Data )ointer.

The D)T! is used in operations regarding e%ternal !$M and some instructions involving code

memory. Since it is an unsigned 6 byte integer value, it can represent values from h to

h A through 57,787 DecimalB.

)CON ,)o:er Contro$ #ress 75-6

The ):@ S! is used to control the 471s power control modes. ertain operation

modes of 471 allow the 471 to go in to a type of +sleep- mode, which re&uires much less

power.

SM:D >> >> >> =1 = )D ?D2 F

SM:DL Double baud rate bit. ?f Timer 1 is used to generate baud rate and SM:D

R 1, the baud rate is doubled when the Serial )ort is used in modes 1, 6,

or 8

@ot implemented, reserved for future use.



=1 =eneral )urpose flag bit.

= =eneral )urpose flag bit.

)D )ower Down bit. Setting this bit activates )ower Down operation.

?D2 ?dle Mode bit. Setting this bit activates ?dle Mode operation.

TCON ,Timer Contro$ #ress 77 Bit


46/109


T1L Timer 1 overflow flag. Set by hardware when the Timerounter 1 overflows.

leared by hardware as the processor vectors to the interrupt service routine.

T!1L Timer 1 run control bit. Setcleared by software to turn Timerounter 1 :@:.

TL Timer overflow flag. Set by hardware when the Timerounter overflows.

leared by hardware as the processor vectors to the service routine.

T!L Timer run control bit. Setcleared by software to turn Timerounter :@:.

?31L 3%ternal ?nterrupt 1 edge flag. Set by hardware when the 3%ternal ?nterrupt edge

is detected. leared by hardware when the interrupt is processed.

?T1L ?nterrupt 1 type control bit. Setcleared by software to specify falling edgelow

level triggered e%ternal ?nterrupt.

?3L 3%ternal ?nterrupt edge flag. Set by hardware when 3%ternal ?nterrupt edge

detected. leared by hardware when interrupt is processed.

?TL ?nterrupt type control bit. Setcleared by software to specify falling edgelow

level triggered e%ternal ?nterrupt.

TMOD ,Timer Moe #ress 79-6

The timer mode S! is used to configure the mode of operation of each of the two

timers. (sing this S! your program may configure each timer to be a 15>bit timer, an 4>bit auto

reload timer, a18>bit timer, are two separate timers.

=$T3 T M1 M =$T3 T M1 M F

=$T3L Chen T!% Ain T:@B is set and =$T3 R 1, T?M3!:(@T3!% runs only

while the ?@T% pin is high Ahardware controlB. Chen =$T3 R ,

T?M3!:(@T3!% will run only while T!% R 1 Asoftware controlB.

TL Timer or ounter selector. leared for Timer operation Ainput from internal

system clockB. Set for ounter operation Ainput from T% input pinB.

M1 Mode selector bit.

M Mode selector bit.

M1 M2 MODE DESCRI)TION

18 #it counter

1 1 15 #it counter

1 6 4 #it counter with auto reload

1 1 8 Split timer into 4bit counters or

05


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timer

T*=AT>= ,Timer = *o:A>i/ #resses 7#A7B-6

These two S!s, taken together represent timer . Their e%act behavior depends on how

the timer is configured in the TM:D S!. "owever, these timers always count up.

T*1AT>1 ,Timer 1 *o:A>i/ #resses 7CA7D-6

These two S!s, taken together represent timer 1. Their e%act behavior depends on how

the timer is configured in the TM:D S!. "owever, these timers always count up.

)1 ,)ort 1 #ress 9= Bitbit ($!TQ baudRvariable

1 6 >bit ($!TQ baudRf86 or f50

1 1 8 >bit ($!TQ baudRvariable

SBUF ,Seria$ Buffer #ress 99-6

0F


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The S#( is used to send and receive data via on>board serial port. S#( serves as the

output port when written to and as an input port when read from.

)2 ,)ort 2 #ress #= Bit


49/109


interrupt will be able to interrupt the serial interrupt routine since serial interrupt routine has the

high priority.

>>>> >>>>> )T6 )S )T1 )E1 )T )E F

?).F @ot implemented, reserved for future use.

?).5 @ot implemented, reserved for future use.

)T6 ?).7 Defines the Timer 6 interrupt priority level A$T476 onlyB.

)S ?).0 Defines the Serial )ort interrupt priority level.

)T1 ?).8 Defines the Timer 1 interrupt priority level.

)E1 ?).6 Defines 3%ternal ?nterrupt 1 priority level.

)T ?).1 Defines the Timer interrupt priority level.

)E ?). Defines the 3%ternal ?nterrupt priority level.

)S& ,)ro/ram Status &or #ress D= Bitar:are etai$s6

The on chip oscillator of 471 can be used to generate system clock. Depending upon

version of the device, crystals from 8.7 to 16 M"9 may be used for this purpose. The system

clock is internally divided by 5 and the resultant time period becomes one processor cycle. The

0


50/109


instructions take mostly one or two processor cycles to e%ecute, and very occasionally three

processor cycles. The $23 Aaddress latch enableB pulse rate is 15th of the system clock, e%cept

during access of internal program memory, and thus can be used for timing purposes.

1=.7.1 #T79C31 Seria$ port pins

)IN #*TERN#TE USE SFR

)8.:!ED Serial data input S#(

)8.?TED Serial data output S#(

)8.6?@T: 3%ternal interrupt T:@>1

)8.8?@T1 3%ternal interrupt 1 T:@> 6

)8.0T: 3%ternal timer input TM:D

)8.7T1 3%ternal timer 1 input TM:D

)8.5C! 3%ternal memory write pulse >>>>>>>>>)8.F!D 3%ternal memory read pulse >>>>

Table F.6

The two internal timers are wired to the system clock and prescaling factor is decided by the

software, apart from the count stored in the two bytes of the timer control registers. :ne of the

counters, as mentioned earlier, is used for generation of baud rate clock for the ($!T. ?t would

be of interest to know that the 476 has a third timer which is usually used for generation of baud

rate.

The reset input is normally low and taking it high resets the micro controller, ?n the

present hardware, a separate M:S circuit has been used for generation of reset signal so that it

could be used to drive e%ternal devices as well.

1=.9 &ritin/ te soft:are6

The 471 has been specifically developed for control applications. $s mentioned

earlier, out of the 164 bytes of internal !$M, 15 bytes have been organi9ed in such a way that all

the 164 bits associated with this group may be accessed bit wise to facilitate their use for bitsetresettest applications. These are therefore e%tremely useful for programs involving individual

logical operations.. The 471 has short branch instructions for Kwithin pageK and conditional

*umps, short *umps and calls within 6k memory space which are very convenient, and as such the

controller seems to favor programs which are less than 6k byte long. Some versions of 4F71

7


51/109


3)!:M device have a security bit which can be programmed to lock the device and then the

contents of internal program 3)!:M cannot be read.

The device has to be erased in full for further alteration, and thus it can only be reused

but not copied. 33)!:M and 2$S" memory versions of the device are also available now.

1=.9.1 Inputdirectional ports. Chen working with ports, first of all it is necessary to

choose which port we need to work with, and then to send data to, or take it from the port. Chen

working with it the port acts like a memory location. Something is simply being written into or

read from it, and it could be noticed on the pins of the micro>controller.

71


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DIS)*#Y DRI+ERS

11. DIS)*#Y DRI+ERS

The devices that are used to drive the rows and columns in the display are latches and

decoders. 2atch is used as row selector and decoder is used as column selector.

11.1 *#TC> ,5*S35"-6

The F0$2S7F8# is an octal transparent latch coupled to eight 8>State output devices. Thetwo sections of the device are controlled independently by enable A3B and output enable A:3B

control gates. The F0$2S7F8# has a broadside pin out configuration to facilitate ) board

layout and allow easy interface with microprocessors. The data on the D inputs is transferred to

the latch outputs when the enable A3B input is high. The latch remains transparent to the data

76


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input while 3 is high, and stores the data that is present one setup time before the "igh>to>2ow

enable transition.

11.1.1 )in Dia/ram Trut Tab$e6

ig 11.1 Table 11.1

11.1.2 *o/i% Dia/ram6

ig 11.6

Chen the 2$T" 3@$#23 A23B input is "?=", the O outputs will follow the D inputs.

Chen the 2$T" 3@$#23 goes 2:C, data at the D inputs will be retained at the outputs until

2$T" 3@$#23 returns "?=" again. Chen a "?=" logic level is applied to the :(T)(T

78


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:@T!:2 : input, all outputs go to a "?=" impedance state, regardless the F0" logic

family is speed, function and pin out compatible with the standard F02S logic family. $ll inputs

are protected from damage due to static discharge by internal diode clamps to ' and ground.

11.1." Features6

Typical propagation delayL 14 ns

Cide operating voltage rangeL 6 to 5 volts

2ow input currentL 1 V$ ma%imum

2ow &uiescent currentL 4 V$ ma%imum AF0" SeriesB

ompatible with bus>oriented systems

:utput drive capabilityL 17 2S>TT2 loads

11.2 DECODERS ,5>C13-6

The decoder used is F0"170. ?t is a 60>pin dual in line package. The F0""T170 arehigh>speed Si>gate M:S devices and are pin compatible with low power Schottky TT2A2STT2B.

The F0""T170 decoders accept four active "?=" binary address inputs and provide15 mutually e%clusive active 2:C outputs. The 6>input enable gate can be used to strobe thedecoder to eliminate the normal decoding +glitches- on the outputs, or it can be used for the

e%pansion of the decoder. The enable gate has two $@Ded inputs which must be 2:C to enablethe outputs. The +170- can be used as a 1>to>15 demultiple%er by using one of the enable inputsas the multiple%ed data input. Chen the other enable is 2:C, the addressed output will followthe state of the applied data.

11.2.1 )in Dia/ram Trut Tab$e6

70


55/109


ig 11.8 Table 11.6

11.2.2 Features6

Typical propagation delayL 61 ns

)ower supply &uiescent currentL 4 V$

Cide power supply voltage rangeL 6;5'

2ow input currentL 1 V$ ma%imum

7.2." *o/i% Dia/ram6

77


56/109


ig 4.0

75


57/109


DIS)*#YS

12. DIS)*#YS

12.1 Introu%tion

There are so many types of displays which are generally classified into 6 ways.

7F


58/109


1B =aseous Type Display

6B Semi onductor Display

12.1.1 (#SEOUS TY)E DIS)*#Y CONSISTS OF6

1B @eon gas displays.

6B Discrete number gaseous displays.

The =aseous type of displays are not used because of higher voltage involved in it and

moreover they are not versatile i.e. they cannot be used to display any other character other than

number.

12.1.2 SEMI CONDUCTOR DIS)*#YS #RE6

1. Seven Segment Display

6. 2D Display

8. 23D Dot Matri% Display

Seven Segment Display cannot be used as they cannot display the character other than

numbers.

2D displays are not used for big display applications, because it is small in si9e and it

will not give illumination as much as compared to that of 23D.

23D Dot Matri% displays are used for this purpose

12.2 *i/t Emittin/ Dioe

The most common and simplest display device used with ? logic is the light emitting

diode A23DB. 23DS are solid state devices, )>@ *unctions which emit light energy when

stimulated by a low voltage direct current. The most efficient 23D is in the visible spectrum and

emits red light, it is most commonly used for 23D displays. $mber and =reen 23Ds are also

available.

23DS are popular for many reasons. #ecause they can be operated from low voltages,

they are compatible with systems that use integrated circuits. They are small 2ightweight, and

mechanically rugged. $s solid state device, they are highly reliable and have typical operation

life of more than 1, , "ours.

74


59/109


The 23D emits light when forward biased, and the intensity of light is a function of the

forward current through the 23D. The voltage drop of a forward biased 23D is essentially fi%ed,

1.5 or 6.0 '. or D operation, the nominal operation current is typically 6ma for red 23Ds.

$ Wunction Diode can emit light or e%hibit electro luminescence Athe emission light from

a solid with the e%citation provided by an electrostatic fieldB. The emitted light in this case

comes from hole ; electron recombination. This becomes clear that when a free electron

recombines, it may fall the way from an unbound as higher energy level to its ground state

releasing a photon of a wavelength corresponding to the energy level difference associated with

this transition.

?n solid state light>emitting diodes A23DsB the supply of higher energy electron is

provided by forward biasing the diode, thus in*ecting electrons into n>region Aand holes into the

p>regionB. The in*ected electrons and holes then recombine with the ma*ority carrier near the

*unction. The recombination radiation is emitted in all directions, with most of light observed at

the top surface, since the amount of material between the *unction and the surface is the least.

!adiative and non>radiative transitions are e%perienced in any semi>conductor under forward

bias, but in many cases the non radiative transition predominate or the photon losses are to

e%cessive for observation of any e%ternal radiation.

12.2.1 #0anta/es of *EDs61

QZ ST$!T3D L F>0>60

QZ ?@2(D3S L

M:D71

QZ 2$=S L

QZ '$!?$#23S L

@T1 D$T$ 6"

@T6 D$T$ 61"

?@?TU$DD! D$T$ 66"

M3MU)T! D$T$ 8"

QZ '3T:! $DD!3S3SSL

:!= "

l*mp ?@?T?$2?S$T?:@

:!= #"

push $

push )SC

lcall D?S)2$/

pop )SC

pop $

reti

:!= 1#"

reti

5F


68/109


:!= 68"

push $

push )SC

*bc !?, !33?'3UD$T$

a*mp S?)U"S

!33?'3UD$T$L

mov $, S#(

c*ne $, X$", ST:!3UD$T$

mov !7, X1"

l*mp S?)U"S

ST:!3UD$T$L

c*ne !7, X1", S?)U"S

c*ne $, X7#", ST:!3UD$T$1

ST:!3UD$T$1L

*nc S?)U"S

mov !7, X"

mov !1, $

inc !1

c*ne $, XKHK, S?)U"S

dec !1

mov !1, XK K

inc !1

mov !1, XK K

inc !1

mov !1, XK K

54


69/109


inc !1

mov !1, XKHK

call 2::)U!ST

mov !1, XM3MU)T!

S?)U"SL

pop )SC

pop $

reti

QZ?@?T?$2?S$T?:@L

mov ), X"

mov )1, X"

mov )6, X"

mov )8, X"

mov S), X57"

mov D)T!, X0"

mov TM:D, X61"

anl pcon, XFfh Q set smod

mov th1, Xf0h Q set T"1 for 60 rate.

mov scon, X76h Q set M:D3 1, !3@.

mov ?3, X6"

setb T!

setb T!1

mov !7, X"

mov !6, X"

5


70/109


mov !8, X"

mov !0, X"

mov !1, XM3MU)T!

call 2::)U!ST

mov !, XM3MU)T!

mov !1, XM3MU)T!

mov ?@?TU$DD!, !

setb !3@

mov !1, XK$K

inc !1

mov !1, XK#K

inc !1

mov !1, XKK

inc !1

mov !1, XKDK

inc !1

mov !1, XK3K

inc !1

mov !1, XKK

inc !1

mov !1, XK=K

inc !1

mov !1, XK"K

inc !1

QZM$?@L

F


71/109


lmp M$?@

QZD?S)2$/L

c*ne !,XKHK, =:U:!UD?S)

mov !, XM3MU)T!

mov ?@?TU$DD!, !

=:U:!UD?S)L

call 2:$DU"$!

mov $, !8

movc $, $ N D)T!

mov ), $

clr )6.F

clr )6.5

nop

setb )6.F

setb )6.5

nop

mov )6, !6

mov $, !6

*b $.0, S323T1

clr )6.0

setb )6.7

S323T1L

*nb $.0, S323T6

clr )6.7

setb )6.0

F1


72/109


S323T6L

inc !8

c*ne !8, X4", S?)U"$!

mov !8, X"

inc !

c*ne !, X58", ST:)U:'

dec !

ST:)U:'L

inc @T1

mov $, @T1

c*ne $, X4", S?)U"$!

mov @T1, Xh

inc ?@?TU$DD!

S?)U"$!L

inc !6

c*ne !6, X6", S?)U!32:$D

mov !6, X"

mov !, ?@?TU$DD!

S?)U!32:$DL

mov T", XD" Q > D R 0.7mS

mov T2, X"

!3T

2::)U!STL

F6


73/109


mov !1, XKHK

inc !1

c*ne !1, X56", 2::)U!ST

!3T

2:$DU"$!L

c*ne !,XK$K, @:TU:!U$

mov D)T!, X23TU$

ret

@:TU:!U$L

c*ne !,XK#K, @:TU:!U#

mov D)T!, X23TU#

ret

@:TU:!U#L

c*ne !,XKK, @:TU:!U

mov D)T!, X23TU

ret

@:TU:!UL

c*ne !,XKDK, @:TU:!UD

mov D)T!, X23TUD

ret

@:TU:!UDL

c*ne !,XK3K, @:TU:!U3

mov D)T!, X23TU3

ret

@:TU:!U3L

F8


74/109


c*ne !,XKK, @:TU:!U

mov D)T!, X23TU

ret

@:TU:!UL

c*ne !,XK=K, @:TU:!U=

mov D)T!, X23TU=

ret

@:TU:!U=L

c*ne !,XK"K, @:TU:!U"

mov D)T!, X23TU"

ret

@:TU:!U"L

c*ne !,XK?K, @:TU:!U?

mov D)T!, X23TU?

ret

@:TU:!U?L

c*ne !,XKWK, @:TU:!UW

mov D)T!, X23TUW

ret

@:TU:!UWL

c*ne !,XKK, @:TU:!U

mov D)T!, X23TU

ret

@:TU:!UL


F0


75/109


mov D)T!, X23TU2

ret

@:TU:!U2L

c*ne !,XKMK, @:TU:!UM

mov D)T!, X23TUM

ret

@:TU:!UML

c*ne !,XK@K, @:TU:!U@

mov D)T!, X23TU@

ret

@:TU:!U@L

c*ne !,XK:K, @:TU:!U:

mov D)T!, X23TU:

ret

@:TU:!U:L

c*ne !,XK)K, @:TU:!U)

mov D)T!, X23TU)

ret

@:TU:!U)L

c*ne !,XKOK, @:TU:!UO

mov D)T!, X23TUO

ret

@:TU:!UOL

c*ne !,XK!K, @:TU:!U!

mov D)T!, X23TU!

F7


76/109


ret

@:TU:!U!L

c*ne !,XKSK, @:TU:!US

mov D)T!, X23TUS

ret

@:TU:!USL

c*ne !,XKTK, @:TU:!UT

mov D)T!, X23TUT

ret

@:TU:!UTL

c*ne !,XK(K, @:TU:!U(

mov D)T!, X23TU(

ret

@:TU:!U(L

c*ne !,XK'K, @:TU:!U'

mov D)T!, X23TU'

ret

@:TU:!U'L

c*ne !,XKCK, @:TU:!UC

mov D)T!, X23TUC

ret

@:TU:!UCL

c*ne !,XKEK, @:TU:!UE

mov D)T!, X23TUE

ret

F5


77/109


@:TU:!UEL

c*ne !,XK/K, @:TU:!U/

mov D)T!, X23TU/

ret

@:TU:!U/L

c*ne !,XKGK, @:TU:!UG

mov D)T!, X23TUG

ret

@:TU:!UGL

c*ne !,XKK, @:TU:!U

mov D)T!, X23TU

ret

@:TU:!UL


mov D)T!, X23TU1

ret

@:TU:!U1L


mov D)T!, X23TU6

ret

@:TU:!U6L


mov D)T!, X23TU8

ret

@:TU:!U8L

FF


78/109



mov D)T!, X23TU0

ret

@:TU:!U0L


mov D)T!, X23TU7

ret

@:TU:!U7L


mov D)T!, X23TU5

ret

@:TU:!U5L

c*ne !,XKFK, @:TU:!UF

mov D)T!, X23TUF

ret

@:TU:!UFL


mov D)T!, X23TU4

ret

@:TU:!U4L

c*ne !,XKK, @:TU:!U

mov D)T!, X23TU

ret

@:TU:!UL

c*ne !,XK.K, @:TU:!UD:T

F4


79/109


mov D)T!, X23TUD:T

ret

@:TU:!UD:TL

c*ne !,XKXK, @:TU:!U$$

mov D)T!, X23TU$$

ret

@:TU:!US)$3L

mov D)T!, X23TUST$!

ret

:!= 0"

23TU$L

db " Q K$K

db F"

db 16"

db 11"

db 16"

db F"

db "

db "

23TU#L

db " Q K#K

db F"

db 0"

db 0"

db 0"

F


80/109


db 85"

db "

db "

23TUL

db " Q KK

db 83"

db 01"

db 01"

db 01"

db 66"

db "

db "

23TUDL

db " Q KDK

db F"

db 01"

db 01"

db 01"

db 83"

db "

db "

23TU3L

db " Q K3K

db F"

db 0"

4


81/109


db 0"

db 01"

db 01"

db "

db "

23TUL

db " Q KK

db F"

db "

db "

db 1"

db 1"

db "

db "

23TU=L

db " Q K=K

db 83"

db 01"

db 0"

db 0"

db 8$"

db "

db "

23TU"L

db " Q K"K

41


82/109


db F"

db 4"

db 4"

db 4"

db F"

db "

db "

23TU?L

db " Q K?K

db "

db 01"

db F"

db 01"

db "

db "

db "

23TUWL

db " Q KWK

db 8"

db 0"

db 0"

db 0"

db 8"

db "

db "

46


83/109


23TUL

db " Q KK

db F"

db 4"

db 10"

db 66"

db 01"

db "

db "

23TU2L

db " Q K2K

db F"

db 0"

db 0"

db 0"

db 0"

db "

db "

23TUML

db " Q KMK

db F"

db 6"

db 0"

db 6"

db F"

48


84/109


db "

db "

23TU@L

db " Q K@K

db F"

db 6"

db 0"

db 4"

db F"

db "

db "

23TU:L

db " Q K:K

db 83"

db 01"

db 01"

db 01"

db 83"

db "

db "

23TU)L

db " Q K)K

db F"

db "

db "

40


85/109


db "

db 5"

db "

db "

23TUOL

db " Q KOK

db 83"

db 01"

db 71"

db 51"

db F3"

db "

db "

23TU!L

db " Q K!K

db F"

db "

db 1"

db 6"

db 05"

db "

db "

23TUSL

db " Q KSK

db 65"

47


86/109


db 0"

db 0"

db 0"

db 86"

db "

db "

23TUTL

db " Q KTK

db 1"

db 1"

db F"

db 1"

db 1"

db "

db "

23TU(L

db " Q K(K

db 8"

db 0"

db 0"

db 0"

db 8"

db "

db "

23TU'L

45


87/109


db " Q K'K

db 1"

db 6"

db 0"

db 6"

db 1"

db "

db "

23TUCL

db " Q KCK

db 8"

db 0"

db 8"

db 0"

db 8"

db "

db "

23TUEL

db " Q KEK

db 58"

db 10"

db 4"

db 10"

db 58"

db "

4F


88/109


db "

23TU/L

db " Q K/K

db 1"

db 6"

db F"

db 6"

db 1"

db "

db "

23TUGL

db " Q KGK

db 51"

db 71"

db 0"

db 07"

db 08"

db "

db "

23TUL

db " Q KK

db 83"

db 71"

db 0"

db 07"

44


89/109


db 83"

db "

db "

23TU1L

db " Q K1K

db "

db 06"

db F"

db 0"

db "

db "

db "

23TU6L

db " Q K6K

db 05"

db 51"

db 71"

db 0"

db 05"

db "

db "

23TU8L

db " Q K8K

db 66"

db 01"

4


90/109


db 0"

db 0"

db 85"

db "

db "

23TU0L

db " Q K0K

db 8"

db 64"

db 60"

db 66"

db F"

db "

db "

23TU7L

db " Q K7K

db 6"

db 0"

db 0"

db 0"

db 81"

db "

db "

23TU5L

db " Q K5K


91/109


db 83"

db 71"

db 0"

db 0"

db 86"

db "

db "

23TUFL

db " Q KFK

db 01"

db 61"

db 11"

db "

db F"

db "

db "

23TU4L

db " Q K4K

db 85"

db 0"

db 0"

db 0"

db 85"

db "

db "

1


92/109


23TUL

db " Q KK

db 65"

db 0"

db 0"

db 0"

db 83"

db "

db "

23TUST$!L

db " Q KHK

db 5#"

db 1"

db F"

db 1"

db 5#"

db "

db "

23TUS)$3L

db " Q K K

db "

db "

db "

db "

db "

6


93/109


db "

db "

23TUD:TL

db " Q K.K

db 5"

db 5"

db "

db "

db "

db "

db "

db K.K

db K,K

db KGK

3@D

8


94/109


*IST OF COM)ONENTS

13. *IST OF COM)ONENTS

0


95/109


TY)E N#ME U#NTITY

? $T471 1

? F0"170 6

? F02S7F8 1? M$E 686 1

? 2MF47 6

)ort !S686 1

Transistor #704 1

Transistor # 70F 15

Transistor # 77F 50

Diodes 1@0F 7

23D !3D 6

4%423D Matri% Display Segments 0

apacitors 1 uf67v 1

apacitors 1 uf67v 6

apacitors 88 pf 6

apacitors 1 uf 0

Transformer >68>>' A1$B 1

rystal 11.75 M"G 1

Transmitter STT088 1

!eceiver ST!088 1

Sip !egister A1 pinB 1 k 1

!esistor 1 k 1

!esistor 1 k 0

!esistor 66 k 1

!esistor 1 ohms 86

7


96/109


RESU*TS

14. Resu$ts

5


97/109


Chen we entered the message in ) it displayed in display board, scrolling from right toleft. #elow figure shows how the characters are displayed and scrolled in the displayboard.

ig 15.1

ig 15.6

ig 15.8

#y default if there is no input to the microcontroller, it displays $#D3=". ?f we needto display any message we have to enter it in ) starting and ending with star. The

distance between the transmitter and receiver should be ma%imum of 7m in noise freearea.

F


98/109


#))*IC#TIONS

#D+#NT#(ES #ND

DIS#D+#NT#(ES

4


99/109


15. #))*IC#TIONS #D+#NT#(ES #ND

DIS#D+#NT#(ES

#pp$i%ations

Moving Message Displays are ideal for all type of commercial establishments

like "otels, !estaurants, !etail Shops, #anks, $irports, linics, "ospitals and other such

places to get ma%imum attention of people.

?n "otels to display welcome notes and costs of all items

?n #anks to display special offers, new plans and various services of them

?n $irports to display arrival and departure timings of planes, and special

attention messages

?n !ailway stations to display platform numbers, arrival and departure

timings of trains, and special attention messages and

?n crowd areas or road sides to display messages and ads of =ovt.

services, !etail shops and industries.

#0anta/es

The message to be displayed can be changed as often we need, by using ).

The cable is not necessary in between transmitter and receiver. So the receiver can

be placed anywhere in the particular range from the transmitter.

Multiple receivers can be used for a single transmitter.

apital alphabets A$>GB, numbers A>B, dot A.B and space can be displayed

Disa0anta/es6

There should be a power supply board at the location of receiver.

The receiver may be affected by the noise in noisy areas. ?f noise e%ists in

received signal the display displays star AHB symbol instead of that character.

This can not be used for longer distances.


100/109


Small Aa>9B and some special characters like ^, , P,etc. are not displayed

due to the lack of memory.

FUTURE SCO)E

1


101/109


17. FUTURE SCO)E

$s there is a rapid growth in electronics, moving message displays replaces the presentdays advertising methods like banners, wall postersetc.

#y using batteries of 7v dc or solar energy systems we can overcome lack of

power supply at the location of receiver.

#y increasing the transmitter power we can increase the coverage for the receivers

so that we can place receivers at very far distances also.

#y using e%ternal memory we can display more characters by writing code for

more no. of characters.

#y using noise filters we can eliminate the noise completely.

no. of characters that are displayed can be increased by using more no. of 23D

matri% and decoders

11


102/109


DESI(NIN( COST

16


103/109


19. DESI(NIN( COST

TY)E N#ME U#NTITY COST

? $T471 1 07.

? F0"170 6 60.

? F02S7F8 1 1.

? M$E 686 1 5.

? 2MF47 6 7.

)ort !S686 1 F.

Transistor #704 1 1.

Transistor # 70F 15 15.

Transistor # 77F 50 50.

Diodes 1@0F 7 F.7

23D !3D 6 0.

4%423D Matri% Display Segments 0 5.

apacitors 1 uf67v 1 6.

apacitors 1 uf67v 6 6.

apacitors 88 pf 6 6.

apacitors 1 uf 0 1.

Transformer >68>>' A1$B 6 16.

rystal 11.75 M"G 1 17.

Transmitter STT088 1 67.

!eceiver ST!088 1 8.

Sip !egister A1 pinB 1 k 1 8.

!esistor 1 k 1 1.

!esistor 1 k 0 0.

!esistor 66 k 1 1.

!esistor 1 ohms 86 86.

18


104/109


>>>>>>>>>>>>>>>>>>>>

Total R 1,074.7

Tota$ Cost of te )roGe%t it6

or )# design >> F7.

omponents >> 1,074.7

Miscellaneous >> 6.


105/109


2=. IM#(ES OF 'IT

Fi/ 2=.1Transmitter se%tion top 0ie:

17


106/109


Fi/ 2=.2 Re%ei0er se%tion top 0ie:

Fi/ 2=." isp$a! front 0ie:

15


107/109


Fi/ 2=. isp$a! :it isp$a!in/ %ara%ters

1F


108/109


BIB*IO(R#)>Y

21. BIB*IO(R#)>Y

Referen%e Boos

$dvanced Microprocessors and )eripherals

> $ !ay ^ M #hurchandi

3lectronic ircuit $nalysis

> . 2al ishore

Switching Theory and 2ogic Design

14


109/109


> Marrius Mano

Microprocessor and its ?nterfacing

> =odsey

Referen%e :ebsites

httpLwww.atmel.com

httpLwww.datasheetcatalog.com

httpLdatasheets.ma%im>ic.com

httpLen.wikipedia.org

httpLwww.electro>tech>online.com

httpLwww.best>microcontroller>pro*ects.com

httpLwww.nu%ie1.com

httpLwww.cadstarworld.com

h di hi
http://www.atmel.com/http://www.datasheetcatalog.com/http://datasheets.maxim-ic.com/http://en.wikipedia.org/http://www.electro-tech-online.com/http://www.best-microcontroller-projects.com/http://www.nuxie1.com/http://www.cadstarworld.com/http://www.atmel.com/http://www.datasheetcatalog.com/http://datasheets.maxim-ic.com/http://en.wikipedia.org/http://www.electro-tech-online.com/http://www.best-microcontroller-projects.com/http://www.nuxie1.com/http://www.cadstarworld.com/

Date post:	02-Mar-2018
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Moving Message Display System

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