Project report

WIRELESS NOTICE BOARD USING ZIGBEE
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1. INTRODUCTION
1.1EMBEDDEDSYSTEMS
An Embedded System is a combination of computer hardware and software, and
perhaps additional mechanical or other parts, designed to perform a specific function.
An embedded system is a microcontroller-based, software driven, reliable, real-time
control system, autonomous, or human or network interactive, operating on diverse
physical variables and in diverse environments and sold into a competitive and cost
conscious market.
An embedded system is not a computer system that is used primarily for processing,
not a software system on PC or UNIX, not a traditional business or scientific
application. High-end embedded & lower end embedded systems. High-end
embedded system - Generally 32, 64 Bit Controllers used with OS. Examples Personal
Digital Assistant and Mobile phones etc. Lower end embedded systems - Generally 8,
16 Bit Controllers used with a minimal operating systems and hardware layout
designed for the specific purpose. Examples Small controllers and devices in our
everyday life like Washing Machine, Microwave Ovens, where they are embedded in.
1.2 CHARACTERISTICS OF EMBEDDED SYSTEMS
 An embedded system is any computer system hidden inside a product other than a
 They will encounter a number of difficulties when writing embedded system
softwar
 Throughput – Our system may need to handle a lot of data in a short period of
 Response–
 Testability–Setting up equipment to test e
 Debug ability–Without a screen or a keyboard, finding out what the software is
 Reliability – embedded systems must be able to handle any situation without
 Memory space – Memory is limited on embedded systems, and you must make
 Program installation – you will need special tools to get your software into

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 Power consumption – Portable systems must run on battery power, and the
 Processor hogs – computing that requires large amounts of CPU time can
 Cost – Reducing the cost of the hardware is a concern in many embedded system
projects; software often operates on hardware that is barely adequate for the job.
 Embedded systems have a microprocessor/ microcontroller and a memory. Some
have a serial port or a network connection. They usually do not have keyboards,
screens or disk drives.
1.3 APPLICATIONS
 Military and aerospace embedded software appl




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 Intelligent, autonomous sensors.
1.4 CLASSIFICATION


 A right answer after the dead line is a wrong answer.
1.4.1 RTS CLASSIFICATION

 Soft Real Time System.
1.4.1.1 HARD REAL TIME SYSTEM
 "Hard" real-
 Example: Nuclear power system, Cardiac pacemaker.
1.4.1.2 SOFT REAL TIME SYSTEM
 "Soft" real-time systems have reduced constrains on "lateness" but still must
 Example: Railway reservation system – takes a few extra seconds the data
remains valid.

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2. LITERATURE SURVEY
2.1 PROBLEM STATEMENT
In practice, many educational institute uses paper notice board and they appoint
particular person to maintain such board. Some other commercial offices and institute
also use GSM based notice board but in that system there is no provision to retrieve
message after power failure and those system can display garbage message on notice
board when SIM receive company’s offer or wrong person’s message. Everyone who
knows that SIM no. can access that notice board.
In Existing GSM based system the system don’t have provision to retrieve message.
And whenever message from company or other person come on that SIM card, system
display garbage message on notice board. All this drawback of existing system
overcome in proposed system
2.2 SOLUTION
In our proposed system, we proposed model of wireless notice board which uses Zig
Bee modules for transmit and receive notice message from PC to display board.
Notice message from PC is send to ARM board serially through terminal software and
message is saved in EEPROM of the ARM. And this messaged is display on notice
board which is serially connected to ARM.
The message is transmitted to serial display of SUNROM which is rolling character
display. This can show up to 256 characters. After sending the message the user can
disconnect the keyboard or transmitter section. At any time the user can add or
remove or alter the notice message according to his requirement. As the message is
stored in EEPROM it can retrieved from EEPROM. Previously transmitted message
can be display on notice board after power failure.
2.3 DESCRIPTION
Notice boards play a vital role mostly in educational institutions. The events,
occasions or any news, which has to be passed to the students, will be written on the
notice boards present in every floor in the colleges or schools. The present system is
like, a person will be told the news and he has to update this news on all the notice
boards present in the college or school. This will be seen mostly during the
examination seasons.
The time table or the schedule of the exams has to be given to the students. This will
be done by writing the details on the notice boards. But this process consumes a lot
time to update the news on all the notice boards and there may be chances that the
person responsible may commit some mistakes or he may be absent sometimes. So,
this may create disturbances and the entire schedule may be disturbed. To avoid all

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these, Wireless Notice Board have been designed which completely eliminates the
manual work.
This project uses the wireless communication, Zig bee. The Zigbee transmitter will be
present at the Principal or the person related to the issues to be displayed on the notice
board. PC keyboard is used as the input device here in this project. Whenever the user
wants to send the news updated to the notice board, he types that particular message
using keyboard and the same data will be transmitted through Zigbee transmitter.
At the receiving end, the Zigbee receiver and the decoder will be fixed to the display
panel. The receiver receives the data coming from the transmitter and the same data
will be received by the microcontroller at the receiver end. The microcontroller sends
this data to the display unit and thus the message given by the user at the transmitter
Nr end will be displayed.

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3. WIRELESS NOTICE BOARD USING ZIGBEE
AIM
The main aim of this project is to implement wireless data communication in
notice board using Zigbee.
ABSTRACT
The Data Transfer or Receive in wired communication. Now the data transfer or
receive in Wireless communication. This project is used to Transfer the data Using
Wireless Communication. Wireless communication is best communication compare to
wired communication.
In early days, the speed of the Data is controlled only through Wired
Communication. But it is possible to the Data transfer or Receiver of the data from the
Wireless Communication.
In this proposed system, the Transmit or Receive data can be controlled
through Zig-BEE communication from the remote place. The Zig-BEE transmitter
transfers the encoded signal to Zig-BEE receiver. The Zig-BEE receiver receives the
data from and decodes the incoming data that data is fed to microcontroller. The data
transfer to transmitter Zig-BEE to receiver Zig-BEE received data store to
Microcontroller. The receiver data send to LCD display. The LCD display displays
the receiving Message.
3.1 BLOCK DIAGRAM
Transmitter Section:
Fig3.1: Transmitter section
AT89S52LCD
Display
ZIG-BEE
Transceiver
Power Supply

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Fig 3.2: Receiver section
3.2 Description
The system required for this purpose is nothing but, a Microcontroller
based message box. The main components of the kit includes Microcontroller,
Zigbee module. These components are integrated with the display board and thus
incorporate the wireless features. The user sends the information to the zig bee
transmitter through keyboard. The AT commands are serially transferred to the
module. In return the transmitter transmits the stored information to the receiver.
The microcontroller in the receiver section validates the information and then
displays the message in the LCD display board. Various time division
multiplexing techniques have been suggested to make the display boards function
efficiently. The microcontroller used in this case is AT89s52, is used as the Zig
bee module. In this prototype model, LCD display is used for simulation purpose.
During the process of implementation this can be replaced by actual display
boards. In addition to address matching, data can be received by number of
dedicated receivers, and this data is displayed on LCD. It displays the same
message until it’s receives another verified message.

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3.3 SCHEMATIC DIAGRAM
Fig 3.3: Schematic Diagram

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3.4 ADVANTAGES, DISADVANTAGES &APPLICATIONS
3.4.1 APPLICATIONS
 Educational institutions & organizations
 Managing traffic
 Advertisement Conference hall
 Bus/Railway station
 Any Public utility place
3.4.2 ADVANTAGES
 Paper free notice board
 Self-Forming and Self-Healing Network: The ZigBee standard allows nodes
in a network to adjust their communication paths on the fly to increase
robustness. As new nodes are installed they automatically connect to existing
networks. This reduces the effort required to set up a new network or add extra
nodes to a new network. This also means that if a node becomes damaged or
otherwise unable to communicate, links to that node can be rerouted so that
other nodes on the network do not lose connectivity. This happens
automatically without the network needing to be reconfigured.
 Non-Interfering: ZigBee adheres to the IEE 802.15.4 standard and uses the
recognized 2.4GHz industrial, scientific and medical (ISM) band. ISM bands
are reserved and used for license-free communications. Because the bands are
expected to have other signals in nearby channels any communications
protocols using them,
including ZigBee, are designed to be tolerant of interference. Some other bands
are only reserved for general use in certain countries and can be used elsewhere
for more regulated use.
 Standard Signal Equipment: Because ZigBee operates within the standard
2.4GHz band it uses easily available boosters and antennas. This reduces the
final cost of the product and also increases the overall performance of the entire
network.
 Security: While neither IEEE 802.15.4 nor the ZigBee standard specifies a
particular encryption method they both support implementation specific
encryption.
3.4.3 DISADVANTAGES
 The data may be received by another ZigBee having same PAN-ID. The range is
small. Low transmission rate: As seen in the table above, the transmission rate of
ZigBee is very small as compared to the other wireless technologies. ZigBee compliant
manufacturers slow to make an appearance in the market. ZigBee compliance
certification for appliance manufacturers mandates lithium battery use.
 Replacement of existing appliances with ZigBee compliant appliances can be cost.

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4. HARDWARE REQUIREMENTS
HARDWARE COMPONENTS
 Power supply
 Microcontroller
 LCD
 Keyboard interface with microcontroller
 Buzzer
 Zigbee trans receiver
4.1 POWER SUPPLY
Fig 4.1 Power supply
 Transformer
 Rectifier
 Capacitor(Smoothing)
 Voltage Regulator
4.1.1 Step down Transformer
When AC is applied to the primary winding of the power transformer it can either be
stepped downor up depending on the value of DC needed. In our circuit the transformer
of 230v/15-0-15v is used to perform the step downoperation where a 230V AC appears
as 15V AC across the secondary winding. One alteration of input causes the top of the
transformer to be positive and the bottom negative. The next alteration will temporarily
cause the reverse. The current rating of the transformer used in our project is 2A. Apart
from stepping down AC voltages, it gives isolation between the power source and
power supply circuitries

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Fig4.1.1 Step down transformer
4.1.2 Rectifier
In the power supply unit, rectification is normally achieved using a solid state diode.
Diode has the property that will let the electron flow easily in one direction at proper
biasing condition. As AC is applied to the diode, electrons only flow when the anode
and cathode is negative. Reversing the polarity of voltage will not permit electron flow.
A commonly used circuit for supplying large amounts of DC power is the bridge
rectifier. A bridge rectifier of four diodes (4*IN4007) are used to achieve full wave
rectification. Two diodes will conduct during the negative cycle and the other two will
conduct during the positive half cycle. The DC voltage appearing across the output
terminals of the bridge rectifier will be somewhat less than 90% of the applied rms
value. Normally one alteration of the input voltage will reverse the polarities. Opposite
ends of the transformer will therefore always be 180 degree out of phase with each
other.
For a positive cycle, two diodes are connected to the positive voltage at the top
winding and only one diode conducts. At the same time one of the other two diodes
conducts for the negative voltage that is applied from the bottom winding due to the
forward bias for that diode. In this circuit due to positive half cycleD1 & D2 will
conduct to give 10.8v pulsating DC. The DC output has a ripple frequency of 100Hz.

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Since each altercation produces a resulting output pulse, frequency = 2*50 Hz. The
output obtained is not a pure DC and therefore filtration has to be done.
Fig 4.1.2 Rectifier
4.1.3 Capacitor
Filter circuits which are usually a capacitor acting as a surge arrester always follow the
rectifier unit. This capacitor is also called as a decoupling capacitor or a bypassing
capacitor, is used not only to ‘short’ the ripple with frequency of 120Hz to ground but
also to leave the frequency of the DC to appear at the output. A load resistor R1 is
connected so that a reference to the ground is maintained. C1R1 is for bypassing
ripples. C2R2 is used as a low pass filter, i.e. it passes only low frequency signals and
bypasses high frequency signals. The load resistor should be 1% to 2.5% of the load.

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Fig 4.1.3 Smoothing
4.1.4 Voltage Regulator
The voltage regulators play an important role in any power supply unit. The primary
purpose of a regulator is to aid the rectifier and filter circuit in providing a constant DC
voltage to the device. Power supplies without regulators have an inherent problem of
changing DC voltage values due to variations in the load or due to fluctuations in the
AC liner voltage. With a regulator connected to the DC output, the voltage can be
maintained within a close tolerant regionof the desired output. IC7812 and 7805 is used
in this project for providing +12V and +5V supply.
Fig 4.1.4 Voltage Regulator

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4.2 MICROCONTROLLER AT89S52
The AT89C52 is a low-power, high-performance CMOS 8-bit microcomputer
with 4 Kbytes of Flash Programmable and Erasable Read Only Memory (PEROM).
The device is manufactured using Atmel’s high density nonvolatile memorytechnology
and is compatible with the industry standard MCS-51 instruction set and pin out. The
on-chip Flash allows the program memory to be reprogrammed in-system or by a
conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU
with Flash on a monolithic chip, the Atmel AT89C52 is a powerful microcomputer
which provides a highly flexible and cost effective solution to many embedded control
applications.
The AT89C52 provides the following standard features:
 8 Kbytes of In-System Reprogrammable Flash Memory
 Endurance: 1,000 Write/Erase Cycles
 Fully Static Operation: 0 Hz to 24 MHz
 Three-Level Program Memory Lock
 256 x 8-Bit Internal RAM
 32 Programmable I/O Lines
 Three 16-Bit Timer/Counters
 Eight Interrupt Sources
 Programmable Serial Channel

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Fig 4.2.1 Pin Diagram of 89C52
 Port0: Bidirectional, both address and data.
 Port1: Bidirectional, data stored in 5 6 7 pins of port1.
 Port2: Bidirectional, data is sent to p1 continuously, used along with p0 to
provide the 16 bit address for external program memory.
 Port3: It is having some special functions like serial communication, external
interrupts, timers, write, read strobes.
 RST: Reset input
 ALE: Address Latch Enable (ALE) is an output pulse for latching the low byte
of the address during accesses to external memory. This pin is also the program
pulse input (PROG) during Flash programming.
 PSEN: Program Store Enable (PSEN) is the read strobe to external program
memory. When the AT89S52 is executing code from external program
memory, PSEN is activated twice each machine cycle, except that two
PSEN activations are skipped during each access to external data memory.

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 EA/VPP: External Access Enable. EA must be strapped to GND in order
to enable the device to fetch code from external program memory locations
starting at 0000H up to FFFFH.
 XTAL1: Input to the inverting oscillator amplifier and input to the internal
clock operating circuit.
 XTAL2: Output from the inverting oscillator amplifier.
Fig4.2.2: Internal Architecture of AT89C52
Oscillator Characteristics
XTAL1 and XTAL2 are the input and output, respectively, of an
inverting amplifier that can be configured for use as an on-chip oscillator, as
shown in Figure 1. Either a quartz crystal or ceramic resonator may be used. To
drive the device from an External clock source, XTAL2 should be left
unconnected while XTAL1 is driven, as shown in Figure 2.

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Oscillator Connections
Special Function Register(SFR) Memory: -
Special Function Registers (SFR s) are areas of memory that control
specific functionality of the 8051 processor. For example, four SFRs permit
access to the 8051’s 32 input/output lines.
The Accumulator: The Accumulator, as its name suggests is used as a
general register to accumulate the results of a large number of instructions. It
can hold 8-bit (1-byte) value and is the most versatile register.
The “R” registers: The “R” registers are a set of eight registers that are
named R0, R1. Etc. up to R7. These registers are used as auxiliary registers in
many operations.
The “B” registers: The “B” register is very similar to the accumulator in
the sense that it may hold an 8-bit (1-byte) value. Two only uses the “B” register
8051 instructions: MUL AB and DIV AB.
The Data Pointer: The Data pointer (DPTR) is the 8051’s only user
accessible 16-bit (2Bytes) register. The accumulator, “R” registers are all
1-Byte values. DPTR, as the name suggests, is used to point to data. It is used by
a number of commands, which allow the 8051 to access external memory.

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THE PROGRAM COUNTER AND STACK POINTER:
The program counter (PC) is a 2-byte address, which tells the 8051 where the
next instruction to execute is found in memory. The stack pointer like all
registers except DPTR and PC may hold an 8-bit (1-Byte) value
ADDRESSING MODES:
An “addressing mode” refers that you are addressing a given memory location.
In summary, the addressing modes are as follows, with an example of each of
these addressing modes provides important flexibility.
Immediate Addressing MOV A, #20 H
Direct Addressing MOV A, 30 H
Indirect Addressing MOV A, @R0
Indexed Addressing
a. External Direct MOVX A, @DPTR
b. Code Indirect MOVC A, @A+DPTR
Timer 2 Registers:
Control and status bits are contained in registers T2CON and
T2MOD for Timer 2. The register pair (RCAP2H , RCAP2L) are the
Capture / Reload registers for Timer 2 in 16-bit capture mode or
16-bit auto-reload mode .
Interrupt Registers:
The individual interrupt enable bits are in the IE register .
Two priorities can be set for each of the six interrupt sources
in the IP .

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Table.4.2.3 Interrupt registers
Timer 2
Timer 2 is a 16-bit Timer / Counter that can operate as either a
timer or an event counter. The type of operation is selected by bit C/T2 in
the SFR T2CON. Timer 2 has three operating Modes : capture ,
auto-reload ( up or down Counting ) , and baud rate generator . The
modes are selected by bits in T2CON. Timer 2 consists of two 8-bit registers,
TH2 and TL2.
Capture Mode
In the capture mode , two options are selected by bit EXEN2 in
T2CON . If EXEN2 = 0, Timer 2 is a 16-bit timer or counter which
upon overflow sets bit TF2 in T2CON . This bit can then be used to
generate an interrupt. If EXEN2 = 1 , Timer 2 performs the same
operation , but a 1-to-0 transition at external input T2EX also
causes the current value in TH2 and TL2 to be captured into
RCAP2H and RCAP2L , respectively
Auto-reload (Up or Down Counter)

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Timer 2 can be programmed to count up or down when
configured in its 16-bit auto-reload mode. This feature is invoked
by the DCEN (Down Counter Enable) bit located in the SFR
T2MOD . Upon reset , the DCEN bit is set to 0 so that timer 2
will default to count up.
Timer 0
Timer 0 functions as either a timer or event counter in four
modes of operation . Timer 0 is controlled by the four lower bits
of the TMOD register and bits 0, 1, 4 and 5 of the TCON
register.
Mode 0 (13-bit Timer)
Mode 0 configures timer 0 as a 13-bit timer which is set
up as an 8-bit timer (TH0 register) with a modulo 32 presale
implemented with the lower five bits of the TL0 register . The
upper three bits of TL0 register are indeterminate and should be
ignored. Pre scalar overflow increments the TH0 register.
Mode 1 (16-bit Timer)
Mode 1 is the same as Mode 0, except that the Timer
register is being run with all 16 bits. Mode 1 configures timer
0 as a 16-bit timer with the TH0 and TL0 registers
connected in cascade. The selected input increments the TL0
register.
Mode 2 (8-bit Timer with Auto-Reload)
Mode 2 configures timer 0 as an 8-bit timer (TL0 register) that
automatically reloads from the TH0 register. TL0 overflow sets
TF0 flag in the TCON register and reloads TL0 with the
contents of TH0, which is preset by software.
Mode 3 (Two 8-bit Timers)
Mode 3 configures timer 0 so that registers TL0 and TH0
operate as separate 8-bit timers. This mode is provided for
applications requiring an additional 8-bit timer or counter.
4.3 LCD
A liquid crystal display (LCD) is a thin, flat display device made up of any number of
color or monochrome pixels arrayed in front of a light source or reflector. Each pixel
consists of a column of liquid crystal molecules suspended between two transparent

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electrodes, and two polarizing filters, the axes of polarity of which are perpendicular to
each other. Without the liquid crystals between them, light passing throughone would
be blocked by the other. The liquid crystal twists the polarization of light entering one
filter to allow it to pass through the other.
Some of the most common LCDs connected to the controllers are 16X1, 16x2 and 20x2
displays. This means 16 characters per line by 1 line 16 characters per line by 2 lines
and 20 characters per line by 2 lines, respectively.
Data can be placed at any location on the LCD. For 16×1 LCD, the address
locations are:
Table 4.3.1: Address locations for a 1x16 line LCD
Fig 4.3.1 Pin Diagram of LCD
4.4 KEYBOARD INTERFACE
Most microcontrollers require some kind of a human interface. This tutorial describes
one way of doing this i.e. interfacing a standard PS2 keyboard withAt mega
(microcontroller) to display text ona LCD. Two connector types are available, the 5-pin
DIN connector of “5D” type, and the smaller six-pin mini-DIN. The pin assignments

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are shown in the figure. The signal lines are open connector, with pull-up resistors
(internal) located in the keyboard.
CONNECTIONS
Fig 4.4.1 connections
Keyboard connector pin arrangement
Table 4.4.1: Pin arrangement
PS/2 ALGORITHM
TIMING
the protocol is: one start bit (always 0), eight data bits, one odd parity bit and one stop
bit (always 1). The data is valid during the low period (falling edge) of the clock pulse.
The keyboard is generating the clock signal, and the clock pulses are typically 30-50 is
low and 30-50 is high.

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Fig 4.4.2 Timing Diagram
The host system can send commands to the keyboard by forcing the clock line low. It
then pulls the data line low (the start bit). Now, the clock line must be released. The
keyboard will count 10 clock pulses. The data line must be set up to the right level by
the host before the trailing edge of the clock pulse. After the tenth bit, thekeyboard
checks for a high level on the data line (the stop bit), and if it is high, it forces it
low. This tells the host that the data is received by the keyboard. The software in this
design note will not send any commands to the keyboard.
SCAN CODES
The AT keyboard has a scan code associated with each key. When a key is pressed, this
code is transmitted. If a key is held down for a while, it starts repeating. The repeat rate
is typically 10 per second. When a key is released, a “break” code ($F0) is transmitted
followed by the key scan code. For most of the keys, the scan code is one byte. Some
keys like the Home, Insert and Delete keys have an extended scan code, from two to
five bytes. The first byte is always $E0. This is also true for the “break” sequence, e.g.,
E0 F0 xx…
The code supplied with this tutorial is a simple keyboard to RS-232 interface. The scan
codes received from the keyboard are translated into appropriate ASCII characters and
transmitted by the UART. The source code iswritten in C. Keyboard reception is
handled by the interrupt function INT0_interrupt. The reception will operate
independent of the rest of the program. The algorithm is quite simple: Store the value of
the data line at the leading edge of the clock pulse. This is easily handled if the clock
line is connected to the INT0 or INT1 pin. The interrupt function will be executed at
every edge of the clock cycle, and data will be stored at the falling edge. After all bits
are received, the data can be decoded. This is done by calling the decode function. For
character keys, this function will store an ASCII character in a buffer. It will take into
account if the shift key is held down when a key is pressed. Other keys like function
keys, navigation keys (arrow keys, page up/down keys etc.) and modifier keys like Ctrl
and Alt are ignored.
4.5 BUZZER
A buzzer or beeper is a signaling device, usually electronic, typically used in
automobiles, household appliances such as a microwave oven, or game shows.

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It most commonly consists of a number of switches or sensors connected to a control
unit that determines if and which button was pushed or a preset time has lapsed, and
usually illuminates a light on the appropriate button or control panel, and sounds a
warning in the form of a continuous or intermittent buzzing or beeping sound. Initially
this device was based on anelectromechanical system which was identical to anelectric
bell without the metal gong. Often these units were anchored to a wall or ceiling and
used the ceiling or wall as a sounding board. Another implementation with some
AC-connected devices was to implement a circuit to make the AC current into a noise
loud enough to drive a loudspeaker and hook this circuit up to a cheap 8-ohm speaker.
Nowadays, it is more popular to use a ceramic-based piezoelectric sounder like a Son
alert which makes a high-pitched tone. Usually these were hooked up to "driver"
circuits which varied the pitch of the sound or pulsed the sound on and off.
In game shows it is also known as a "lockout system," because when one person signals
("buzzes in"), all others are locked out from signaling. Several game shows have large
buzzer buttons which are identified as "plungers".
The word "buzzer" comes from the rasping noise that buzzers made when they were
electromechanical devices, operated from stepped-down AC line voltage at 50 or 60
cycles. Other sounds commonly used to indicate that a button has been pressed are a
ring or a beep.
4.6 ZIGBEE TRANSRECEIVER
ZigBee is the name of a specification for a suite of high level communication protocols
using small, low-power digital radios based on the IEEE 802.15.4-2006 standard for
wireless personal area networks (WPANs), such as wireless headphones connecting
with cell phones via short-range radio.
It Operates in 868 MHz in Europe, 915 MHz in USA & Australia, and 2.4 GHz
Elsewhere.
LOW POWER CONSUMPTION:
 Consumes < 50 Mill watts when Active and <1 Micro watt when in Sleep mode
 Attained: Low duty Cycle(0.1%) & Sleep mode which consumes very less
power

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MESH NETWORK:
 Forms a Mesh Network between nodes, meshing a chain from one device to
another.
TRANSMISSIONRANGE:
 Transmission Range is 10-100 meters. And this could be extended using Mesh
Network
4.6.1 ZIGBEE FEATURES
LOW COST:
 System simplicity and flexibility make Zig Bee cost-effective
 Low battery storage, absence of memory helps
HIGH RELIABILIY AND AUTOMATION:
 Since more nodes, ZigBee’s are easy to deploy, operate reliably without
Human Intervention.
 Failure in single node will not affect the entire network.
HIGH SECURITY:
 Uses 128 bit AES encryption algorithms for highly secure network.
 Very Difficulty to Hack as it’s used for Control and Sensitive Applications
SELF HEALING:
 As it is mesh topology, a failure in one node, automatically reroutes the path
through other nodes in the network.
SIZE OF ZIGBEE NETWORK:
 Could connect 264 Devices
 64 bit IEEE address,
DISADVANTAGE:
 Low Data rate(Compared to Other Wireless Protocols)
 250 kbps @2.4 GHz, 40 kbps @ 915 MHz, and 20 kbps @868 MHz
4.6.2 Architecture:
Though WPAN implies a reach of only a few meters, 30 feet in the case of Zig Bee, the
network will have several layers, so designed as to enable intrapersonal communication

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within the network, connection to a network of higher level and ultimately an uplink to
the Web.
The Zig Bee Standard has evolved standardized sets of solutions, called ‘layers'. These
layers facilitate the features that make Zig Bee very attractive: low cost, easy
implementation, reliable data transfer, short-range operations, very low power
consumption and adequate security features.
1. Network and Application Support layer: The network layer permits growth of
network sans high power transmitters. This layer can handle huge numbers of nodes.
This level in the Zig Bee architecture includes the Zig Bee Device Object (ZDO),
user-defined application profile(s) and the Application Support (APS) sub-layer.
The APS sub-layer's responsibilities include maintenance of tables that enable
matching between two devices and communication among them, and also discovery,
the aspect that identifies other devices that operate in the operating space of any device.
The responsibility of determining the nature of the device (Coordinator / FFD or RFD)
in the network, commencing and replying to binding requests and ensuring a secure
relationship between devices rests with the ZDO (Zigbee Define Object). The
user-defined application refers to the end device that conforms to the Zig Bee Standard.
2. Physical (PHY) layer: The IEEE802.15.4 PHY physical layer accommodates high
levels of integration by using direct sequence to permit simplicity in the analog circuitry
and enable cheaper implementations.
3. Media access control (MAC) layer: The IEEE802.15.4 MAC media access control
layer permits use of several topologies without introducing complexity and is meant to
work with large numbers of devices.
Figure4.6.2. 1: IEEE 802.15.4 / Zig Bee Stack Architecture

26
DEVICE TYPES:
There are four different types of Zig Bee devices:
 Zig Bee coordinator (ZC): Forms the root of the network .There is exactly one
Zig Bee coordinator ineach.Canstore informationabout the network, including
acting as the Trust Centre & repository for security keys.
 Zig Bee Router (ZR): As well as running an application function a router can
act as an intermediate router, passing data from other devices.
 Zig Bee End Device (ZED): Contains just enough functionality to talk to the
parent node only. This relationship allows the node to be asleep a significant
amount of the time thereby giving long battery life.
 ZigBee's Device Object (ZDO): A special device in a Zig Bee network responsible for a
number of tasks, which include keeping of device roles, management of requests to join a
network, device discovery and security.
Fig 4.6.2.2 Mesh network

27
5. SOFTWARE REQUIREMENTS
5.1 INTRODUCTIONTO KEIL
KeilMicroVision is an integrated development environment used to create software to
be run on embedded systems (like a microcontroller). It allows for such software to be
written either in assembly or C programming languages and for that software to be
simulated on a computer before being loaded onto the microcontroller.
μVision3 is an IDE (Integrated Development Environment) that helps write,
compile, and debug embedded programs. It encapsulates the following components:
 A project manager.
 A make facility.
 Tool configuration.
 Editor.
 A powerful debugger.
To create a new project in uVision3:
1. Select Project - New Project.
2. Select a directory and enter the name of the project file.
3. Select Project –Select Device and select a device from Device Database.
4. Create source files to add to the project
5. Select Project - Targets, Groups, and Files. Add/Files, select Source Group1,
and add the source files to the project.
6. Select Project - Options and set the tool options. Note that when the target
device is selected from the Device Database all-special options are set
automatically. Default memory model settings are optimal for most
applications.
7. Select Project - Rebuild all target files or Build target.
To create a new project, simply start MicroVision and select “Project”=>”New
Project” from the pull–down menus. In the file dialog that appears, choose a name
and directory for the project. It is recommended that a new directory be created for
each project, as several files will be generated. Once the project has been named, the

28
dialog shown in the figure below will appear, prompting the user to select a target
device. In this lab, the chip being used is the “AT89C52,” which is listed under the
heading “Atmel”.
Fig 5.1: Window for choosing target device.
Next, Micro Vision must be instructed to generate a HEX file upon program
compilation. A HEX file is a standard file format for storing executable code that is to
be loaded onto the microcontroller. In the “Project Workspace” pane at the left,
right–click on “Target 1” and select “Options for ‘Target 1’ ”.Under the “Output” tab of
the resulting options dialog, ensure that both the “Create Executable” and “Create HEX
File” options are checked. Then click “OK”.

29
Fig 5.2: Project Options Dialog
Next, a file must be added to the project that will contain the project code. To do
this, expand the “Target 1” heading, right–click on the “Source Group 1” folder, and
select “Add files…”Create a new blank file (the file name should end in “.asm”), select
it, and click “Add.” The new file should now appear in the “Project Workspace” pane
under the “Source Group 1” folder. Double-click on the newly created file to open it in
the editor. All code for this lab will go in this file. To compile the program, first save all
source files by clicking on the “Save All” button, and then click on the “Rebuild All
Target Files” to compile the program as shown in the figure below. If any errors or
warnings occur during compilation, they will be displayed in the output window at the
bottom of the screen. All errors and warnings will reference the line and column
number in which they occur along with a description of the problem so that they can be
easily located. Note that only errors indicate that the compilation failed, warnings do
not (though it is generally a good idea to look into them anyway).
Fig 5.3: Project Workspace Pan

30
Fig 5.4: “Save All” and “Build All Target Files” Buttons
When the program has beensuccessfully compiled, it can be simulated using the
integrated debugger in KeilMicroVision. To start the debugger, select
“Debug”=>”Start/Stop Debug Session” from the pull–down menus.
At the left side of the debugger window, a table is displayed containing several
key parameters about the simulated microcontroller, most notably the elapsed time
(circled in the figure below). Just above that, there are several buttons that control code
execution. The “Run” button will cause the program to run continuously until a
breakpoint is reached, whereas the “Step Into” button will execute the next line of code
and thenpause (the current position in the program is indicated bya yellow arrow to the
left of the code).
Fig 5.5: μVision3 Debugger window

31
6. PROJECT CODE
6.1 SOURCE CODE
TRANSMITTER SECTION
;--Port PIN assignment....
;--Part of this project PC AT Keyboard is accessing--09/05/05
/*=========================================================*/
;-AT key board Key value is displayed on LCD Display..........
; - Checked Final Testing is Ok....21/05/2005..Ok...
;-25/10/2005 &
; This routine is tested all keyboard data entry mode, It displays properly in Row buy Row
; Tested OK....25/10/2005 10:57 PM
/***********************************************************/
LCD_DPort equ P0
LCD_Rs equ P1.5
LCD_RW equ P1.6
LCD_CS equ P1.7
TstLED1 equ P3.2
PKP_Clk equ P3.3
PKP_Dat equ P3.4
/*-----------------------------*/
BSTDdata equ 0300
BSTDBranch equ 0350
BSTDRemarks equ 0400
/*-------------------------------------------*/
; Internal RAM variables
TempKey Data 30h ; key Pressed Temp value
DlayC1 Data 31h
DlayC2 Data 32h
DlayC3 Data 33h
V50mSec Data 34h
V100mSec Data 35h
VSec Data 36h
rxcnt Data 37h
txcnt Data 38h
IntCount equ r3
IntBCnt equ r4
ScrCount equ r5
/*---------------------------------*/
;-RAM bit addressable memory assignment
FKeyPress Bit 01h

32
FCaps bit 02h
FSmall bit 03h
VStack Data 50h
/*--------------------------------*/
ORG 0000h
ljmp Power_On
ORG 000Bh
ljmp Timer0_ISR ; Interrupt 4every 250uSec
ORG 0013h
ljmp ExInt1_ISR ;External Interrupt for AT Keyboard service
ORG 0023h
ljmp Serial_ISR
ORG 0100h
Power_On:
mov r0,#00h
mov a,#00h
Lclear_Nxt:
mov @r0,a
inc r0
cjne r0,#7fh,Lclear_Nxt
mov r0,#00h
mov 8Eh,#00h
mov SP,#VStack
mov P3,#0ffh
mov R0,#00h
mov R1,#00h
clr FCaps ;default Lower case
call LCD_PInialise ; Power ON LCD Initialisation
/*-------------------------------------*/
; Interrupt Services Enable
clr EA
mov TH0, #3Ch ;Count for 50mSec Interrupt.
mov TL0, #0AFh
mov TH1, #0FDh ;for Baud rate of 9600bps
mov TL1, #0FDh
mov TMOD,#21h ;T1=8-bit auto reload mode for baud rate generation
mov SCON,#50h ;T0=16-bit timer for 50mSec.
mov TCON,#55h ;Serial TxRx enable
mov IE, #96h ;Global Interrupt enable, Serial ISR,T1,T0,Ex1 services Enable
/*---------------------------------------*/
call Displine1
mov Dptr,#WelCome
call DispTitle
call Displine2
mov Dptr,#My_Name
call DispTitle

33
call Delay1Sec
call Delay1Sec
call Delay1Sec
call ClearDisp
call Displine1
mov IntCount,#00 ;for Clock Interupt Counter
mov IntBCnt, #00h ;for Byte count
mov P2,#00h
mov R1,#40h
mov R0,#70h
/*************************************/
Main_Loop:
jb FKeyPress,DispChar
ljmp Main_Loop
/*************************************/
;-Routine for display the Charecters on LCD
DispChar:
clr FkeyPress
mov a,TempKey
mov @R0,a
cjne a,#'Z',exitstore
call ClearDisp
call DispLine2
mov R0,#70h
loop:
mov a,@R0
cjne a,#'Z',loopdisp
mov SBUF,#','
call Delay20mSec
mov R0,#70h
call DispLine1
jmp Main_Loop
loopdisp:
mov SBUF,a
call Delay20mSec
call LCD_Data_out
inc R0
jmp loop
exitstore:
call LCD_Data_out
inc R0
jmp exit
exit:
ljmp Main_Loop
/*-----------------------------------*/
ExInt1_ISR:
inc IntCount

34
mov A,TempKey
cjne IntCount,#10,IntLP1;1st r3=1 ==>IntLp1
IntLP1:
jnc IntLP2
setb PKP_Dat ; always set the port b4 reading
mov c,PKP_Dat
rrc a
mov TempKey,A
IntLP2:
cjne IntCount,#11,IntLP3
mov IntCount,#00
inc IntBCnt
cjne IntBCnt,#03,IntLP3
mov IntBCnt,#00
mov a,TempKey
cjne a,#0F0h,DispLp
jmp IntLP3
DispLp:
cjne a,#58h,ChType
cpl FCaps
jmp IntLP3
ChType: jnb FCaps,GetSmall
mov DPTR,#ScanCodeATcap ;move Dptr=Scan Code Lookup Table address
jmp GetCha
GetSmall:
mov DPTR,#ScanCodeATsmall ;move Dptr=Scan Code Lookup Table address
GetCha:
movc a,@a+Dptr
mov TempKey,A
setb FKeyPress
IntLP3:
reti
/*-----------------------------------*/
Serial_ISR:
push PSW
jbc RI,RX_Service
jbc TI,TX_Service
reti
RX_Service:
POP PSW
mov A,sbuf
mov @R1,a
cjne a,#',',rxst
call ClearDisp
call DispLine1
mov R1,#40h
loopr:
mov a,@R1

35
cjne a,#',',exitr
jmp exitlp
rxst:
inc R1
reti
exitr:
call LCD_Data_out
inc R1
jmp loopr
exitlp:
mov R1,#40h
reti
TX_Service:
clr TI
POP PSW
reti
/*-====----------------------------------------*/
; Timer0 for Every 50mSec Interrupt service routine
Timer0_ISR:
push acc
mov TH0,#3Ch ;Count for 50mSec Interrupt.
mov TL0,#0AFh
inc V50mSec
mov a,V50mSec
cjne a,#04h,End_ISR0
mov V50mSec,#04h
inc V100mSec
mov a,V100mSec
cjne a,#5,End_ISR0
mov V100mSec,#05h
inc VSec
End_ISR0:
pop Acc
reti
/*------------------------------------------*/
;Lcd write command to RS Register
LCD_Cmnd_Out:
call LCD_Busy_Chk
mov LCD_DPort,a
clr LCD_Rs
clr LCD_Rw
setb LCD_CS
NOP
NOP
clr LCD_CS
ret
;LCD write data in to data register
LCD_Data_Out:
call LCD_Busy_Chk

36
mov LCD_DPort,a
setb LCD_Rs
clr LCD_Rw
setb LCD_CS
NOP
NOP
clr LCD_CS
ret
LCD_Busy_Chk:
clr LCD_CS
mov LCD_DPort,#0ffh
clr LCD_Rs
setb LCD_Rw
Wait: clr LCD_CS
setb LCD_CS
jb P0.7,Wait
clr LCD_CS
ret
/*--------------------------------------------------*/
;Power ON LCD Initialisation programe
LCD_PInialise:
mov a,#38h
call LCD_Cmnd_Out
mov a,#06h
call LCD_Cmnd_Out
mov a,#01h
call LCD_Cmnd_Out
mov a,#0ch
call LCD_Cmnd_Out
ret
/*..............................................*/
; This routine displays the LCD Tittles on display
DispTitle:
clr a
Get_Dat:
movc a,@a+dptr
jz Next1
mov SBUF,a
call Delay20mSec
call LCD_Data_Out
inc dptr
clr a
jmp Get_Dat
Next1: ret
/*-------------------------------------------*/
ClearDisp:
mov a,#01h

37
call LCD_Cmnd_Out
ret
DispLine1:
mov a,#80h
call LCD_Cmnd_Out
ret
DispLine2:
mov a,#0C0h
call LCD_Cmnd_Out
ret
DispLine3:
mov a,#94h
call LCD_Cmnd_Out
ret
DispLine4:
mov a,#0D4h
call LCD_Cmnd_Out
ret
/*-------------------------------------------*/
;Deay routine
Delay1sec:
mov DlayC1,#8
mov DlayC2,#155
mov DlayC3,#00h
Here1S: djnz DlayC3,Here1S
djnz DlayC2,Here1S
djnz DlayC1,Here1S
ret
Delay500mSec:
mov DlayC1,#4
mov DlayC2,#155
mov DlayC3,#00h
D500ms: djnz DlayC3,D500ms
djnz DlayC2,D500ms
djnz DlayC1,D500ms
ret
Dlay200mSec:
mov DlayC1,#200
mov DlayC2,#00
here_D2:djnz DlayC2,$
djnz dlayC1,here_D2
ret
Delay20mSec:
mov DlayC1,#40
mov DlayC2,#00
here_Dl:djnz DlayC2,$

38
djnz dlayC1,here_Dl
ret
Delay5uSec:
nop
nop
nop
nop
ret
/*-----------------------------------------------------*/
ScanCodeATcap: ; F3 F1 F2
;0 1 2 3 4 5 6 7 8 9 a b c d e f
DB ' ',' ',' ',' ',04h,05h,06h,',',',',',',',',',',',',',',',','~' ;00-0f
DB ' ',' ',' ',' ',' ','Q','1',' ',' ',' ','Z','S','A','W','2',' ' ;10-1f
DB ' ','C','X','D','E','4','3',' ',' ',' ','V','F','T','R','5',' ' ;20-2f
DB ' ','N','B','H','G','Y','6',' ',' ',' ','M','J','U','7','8',' ' ;30-3f
DB ' ','<','K','I','O','0','9',' ',' ','>','?','L',':','P','_',' ' ;40-4f
DB ' ',' ','"',' ','[','+',' ',' ',' ',' ',5Ah,']',' ','',' ',' ' ;50-5f
DB ' ',' ',' ',' ',' ',' ',' ',' ',' ','1',' ','4','7',' ',' ',' ' ;60-6f
DB '0',' ','2','5','6','8',76h,77h,' ',' ','3',' ',' ','9',' ',' ' ;70-7f
DB ' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ' ;80-8f
DB ' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ' ;90-9f
DB ' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ' ;a0-af
DB ' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '
DB ' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '
DB ' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '
DB ' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '
DB ' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '
DB ' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '
/*====================================================================
======*/
/*-----------------------------------------------------*/
ScanCodeATsmall: ; F3 F1 F2
;0 1 2 3 4 5 6 7 8 9 a b c d e f
DB ' ',' ',' ',' ',04h,05h,06h,',',',',',',',',',',',',',',',','~' ;00-0f
DB ' ',' ',' ',' ',' ','q','1',' ',' ',' ','z','s','a','w','2',' ' ;10-1f
DB ' ','c','x','d','e','4','3',' ',' ',' ','v','f','t','r','5',' ' ;20-2f
DB ' ','n','b','h','g','y','6',' ',' ',' ','m','j','u','7','8',' ' ;30-3f
DB ' ','<','k','i','o','0','9',' ',' ','>','?','l',':','p','_',' ' ;40-4f
DB ' ',' ','"',' ','[','+',' ',' ',' ',' ',5Ah,']',' ','',' ',' ' ;50-5f
DB ' ',' ',' ',' ',' ',' ',' ',' ',' ','1',' ','4','7',' ',' ',' ' ;60-6f
DB '0',' ','2','5','6','8',76h,77h,' ',' ','3',' ',' ','9',' ',' ' ;70-7f
DB ' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ' ;80-8f
DB ' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ' ;90-9f
DB ' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ' ;a0-af
DB ' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '
DB ' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '
DB ' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '
DB ' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '

39
DB ' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '
DB ' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '
/*====================================================================
======*/
WelCome: DB " WIRELESS ",0
My_Name: DB " NOTICE BOARD ",0
END
RECEIVER SECTION
/*....GSM Short Message Service............................*/
/*....Using:Fargo Maestro 20 GSM/GPRS Modem Dual band......*/
/*....Philips 89C51 RD2nb Micro Controller.................*/
/*....Author:G.Satyanarayana...04-05-2005..................*/
/***********************************************************/
;--Port PIN assignment....
;--Part of this project PC AT Keyboard is accessing--09/05/05
/*=========================================================*/
;-AT key board Key value is displayed on LCD Display..........
;- Checked Final Testing is Ok....21/05/2005..Ok...
;-25/10/2005
; this routine is tested all keyboard data entry mode ,It displays properly in Row buy Row
; Tested OK....25/10/2005 10:57 PM
/***********************************************************/
LCD_DPort equ P0
LCD_Rs equ P1.5
LCD_RW equ P1.6
LCD_CS equ P1.7
TstLED1 equ P3.2
PKP_Clk equ P3.3
PKP_Dat equ P3.4
/*-----------------------------*/
BSTDdata equ 0300
BSTDBranch equ 0350
BSTDRemarks equ 0400
/*-------------------------------------------*/
; Internal RAM variables
TempKey Data 30h ; key Pressed Temp value
DlayC1 Data 31h
DlayC2 Data 32h
DlayC3 Data 33h
V50mSec Data 34h
V100mSec Data 35h
VSec Data 36h
IntCount equ r3
IntBCnt equ r4
ScrCount equ r5
/*---------------------------------*/

40
;-RAM bit addressable memory assignment
FKeyPress Bit 01h
FCaps bit 02h
FSmall bit 03h
VStack Data 50h
/*--------------------------------*/
ORG 0000h
ljmp Power_On
ORG 0023h
ljmp Serial_ISR
ORG 0100h
Power_On:
mov r0,#00h
mov a,#00h
Lclear_Nxt:
mov @r0,a
inc r0
cjne r0,#7fh,Lclear_Nxt
mov r0,#00h
mov 8Eh,#00h
mov SP,#VStack
mov P3,#0ffh
SETB P2.0
call LCD_PInialise ;Power ON LCD Initialisation
/*-------------------------------------*/
; Interrupt Services Enable
clr EA
mov TH1, #0FDh ;for Baud rate of 9600bps
mov TL1, #0FDh
mov TMOD,#21h ;T1=8-bit auto reload mode for baud rate generation
mov SCON,#50h ;T0=16-bit timer for 50mSec.
setb TR1 ;Serial TxRx enable
mov IE, #90h ;Global Interrupt enable, Serial ISR,T1,T0,Ex1 services Enable
/*---------------------------------------*/
call Displine1
mov Dptr,#WelCome
call DispTitle
call Displine2
mov Dptr,#My_Name

41
call DispTitle
call Delay1Sec
call Delay1Sec
call Delay1Sec
call ClearDisp
call Displine1
mov R0,#70h
/*----------------------------------*/
Main_Loop:
SETB P2.0
ljmp Main_Loop
/*-----------------------------------*/
Serial_ISR:
push PSW
jbc RI,RX_Service
jbc TI,TX_Service
reti
RX_Service:
CLR P2.0
POP PSW
mov A,sbuf
mov @R0,a
cjne a,#',',rxst
call ClearDisp
call DispLine1
mov R0,#70h
loopr:
mov a,@R0
cjne a,#',',exitr
jmp exitlp
rxst:
inc R0
reti
exitr:
call LCD_Data_out
inc R0
jmp loopr
exitlp:
CALL Delay1sec
mov R0,#70h
reti
TX_Service:

42
clr TI
POP PSW
reti
/*------------------------------------------*/
;Lcd write command to RS Register
LCD_Cmnd_Out:
call LCD_Busy_Chk
mov LCD_DPort,a
clr LCD_Rs
clr LCD_Rw
setb LCD_CS
NOP
NOP
clr LCD_CS
ret
; LCD write data in to data register
LCD_Data_Out:
call LCD_Busy_Chk
mov LCD_DPort,a
setb LCD_Rs
clr LCD_Rw
setb LCD_CS
NOP
NOP
clr LCD_CS
ret
LCD_Busy_Chk:
clr LCD_CS
mov LCD_DPort,#0ffh
clr LCD_Rs
setb LCD_Rw
Wait: clr LCD_CS
setb LCD_CS
jb P0.7,Wait
clr LCD_CS
ret
/*--------------------------------------------------*/
; Power ON LCD Initialisation programe
LCD_PInialise:
mov a,#38h
call LCD_Cmnd_Out
mov a,#06h
call LCD_Cmnd_Out
mov a,#01h
call LCD_Cmnd_Out
mov a,#0ch
call LCD_Cmnd_Out
ret

43
/*..............................................*/
; This routine displays the LCD Tittles on display
DispTitle:
clr a
Get_Dat:
movc a,@a+dptr
jz Next1
call LCD_Data_Out
inc dptr
clr a
jmp Get_Dat
Next1: ret
/*-------------------------------------------*/
ClearDisp:
mov a,#01h
call LCD_Cmnd_Out
ret
DispLine1:
mov a,#80h
call LCD_Cmnd_Out
ret
DispLine2:
mov a,#0C0h
call LCD_Cmnd_Out
ret
DispLine3:
mov a,#94h
call LCD_Cmnd_Out
ret
DispLine4:
mov a,#0D4h
call LCD_Cmnd_Out
ret
/*-------------------------------------------*/
;Deay routine
Delay1sec:
mov DlayC1,#8
mov DlayC2,#155
mov DlayC3,#00h
Here1S: djnz DlayC3,Here1S
djnz DlayC2,Here1S
djnz DlayC1,Here1S
ret
Delay500mSec:
mov DlayC1,#4
mov DlayC2,#155
mov DlayC3,#00h

44
D500ms: djnz DlayC3,D500ms
djnz DlayC2,D500ms
djnz DlayC1,D500ms
ret
Dlay200mSec:
mov DlayC1,#200
mov DlayC2,#00
here_D2:djnz DlayC2,$
djnz dlayC1,here_D2
ret
Delay20mSec:
mov DlayC1,#40
mov DlayC2,#00
here_Dl:djnz DlayC2,$
djnz dlayC1,here_Dl
ret
Delay5uSec:
nop
nop
nop
nop
ret
WelCome: DB " WELCOME TO ",0
My_Name: DB " SPEC ",0
END

45
7. CONCLUSION & FUTURE SCOPE
CONCLUSION
The project ―Wireless Notice Board using Zig Bee has been successfully completed and
tested with integration of the features of every hardware component for its development. We
believe that our step is towards complete automation for notice board application which can
be used in colleges, finally we can conclude that this project application gives a very good
feature and there is huge scope for further research and development for using the same with
the help of advanced technology.
FUTURE ASPECTS
 Could install Multi Point Receivers as Mesh Network so the all the displays could be
controlled using one coordinator
 One more is the use of LED Display Boards instead of and LCD display, which would
be the further improvement in the display and also delimit the number of characters
displayed on the screen.
 Multi lingual display can be one of the added variations of the project. The display
boards are one of the single most important media for information transfer to the
maximum number of end users
 Only used by authenticated users.

46
8. BIBLIOGRAPHY
REFERENCES
 Zig Bee for wireless networking
 Johan Lon Jonas Olsson
 The 8051 Micro controller and Embedded Systems
 Muhammad Ali Mazidi Janice Gillispie Mazidi
 Fundamentals of Microprocessors and Micro computers
B.Ram
 Microprocessor Architecture, Programming & Applications
Ramesh S.Gaonkar
 Electronic Components
D.V.Prasad
 References on the Web:
 www.national.com
 www.atmel.com
 www.microsoftsearch.com
 www.geocities.com
 www.zilog.com –For Data Sheets of various Components
 www.wikepedia.com
 www.keil.com/forum/docs/
 Texas Instruments data sheets

SPEC 47 ECE Dept.

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