16-08-2012, 11:49 AM
PIC Microcontroller based Wireless Notice Board
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ABSTRACT
Wireless systems are gaining popularity rapidly, as people attempt to do
away with complicate and confusing wiring operations. Using existing radio wave
frequencies, battery operated control panels allow for easier operation and
maintenance of the display system.
Wireless Notice Board
Wireless notice board is an enhanced technology used in order to same
time and convey the message with no delay. It provides a wireless data transfer
capability between the PC and the notice board without the need of wiring on
through a radio frequency link.
This is a microcontroller based Embedded System which achieves
wireless interface between a PC and a Notice board. Here a 16x2 alphanumeric
display can be used as the notice board .The user can type the messages to be
displayed in the remote LCD using the hyper terminal of the PC and can be sent
to the notice board using the RF link. The z8 microcontroller (F6423) based
embedded system connected to the serial port of the PC receives the data send
from the PC at the set baud rate and modulates it (ASK Modulation) and sends it
to the display system through the wireless link. At the display side another z8
microcontroller (F6423) based embedded system receives the data through the
RF receiver, demodulates it and sends to the display side.
INTRODUCTION
The project aims at providing wireless (point to multi-point) data transfer
capability between the PC and the notice board without the need of wiring. This
is a microcontroller based Embedded System which achieves wireless interface
between a PC and a Notice board.
Here any display can be used as the notice board .The user can type the
messages to be displayed on the remote display board using the hyper terminal
of the PC and can be sent to the notice board using the RF link. The PIC
microcontroller based Embedded System connected to the serial port of the PC
receives the data sent from the PC at the baud rate set and modulates it (ASK
Modulation) and sends it to the display system through the wireless link.
At the display side another PIC microcontroller based Embedded System
receives the data through the RF receiver, demodulates it and sends to the
display side. Using existing radio wave frequencies, battery operated control
panels allow for easier operation and maintenance of the display system.
This project finds application in Educational Institutions and Offices,
Display boards for advertisement, In Railway stations and Airports to intimate the
passengers. Provides many advantages over the already existing display
boards, as it avoids avoids the need of wiring, as and when needed information
can be displayed, avoids the use of printer, time consumption is less and its user
friendly.
Alphanumeric Display (LCD):
LCD stands for Liquid Crystal Displays. "Liquid crystal" is neither solid nor
liquid (an example is soapy water).Liquid crystals when stimulated by an external
electrical charge will change the properties of light passing through the crystals.
There are two ways to produce a liquid-crystal image with such cells: the
segment driving method and the matrix driving method. The segment driving
method displays characters and pictures with cells defined by patterned
electrodes. The matrix driving method displays characters and pictures in sets of
dots.
In our project we are using 16x2 line matrix driven method display to
display our messages.
Arithmetic Logic Unit (ALU):
The ALU includes electronic circuits (such as adder, comparator and
flags) that are designed to perform logical & arithmetic operations such as
addition, subtraction, logical AND, OR, EXOR.
The register that is used to perform these functions is generally called the
ACCUMULATOR. In this microcontroller this is called the working register (W
Reg) and it is 8-bits wide.
Registers:
The register segment of the microcontroller includes various types of
registers that are used to hold memory addresses. A few important registers are
status register, file select register (FSR) and program counter.
The program counter (PC) is a 13-bit register that holds that program
memory address of the instruction that is to be read next. The MC uses the
program counter as a memory pointer to fetch an instruction. FSR’s are 8-bit
registers that are used in indirect addressing.
Control Unit:
Control Unit is designed to provide timing and control signals to various
read and write operations. This unit oversees the binary information flow
between the MP memory and IO.