1. PC CONTROLLED SCROLLING MESSAGE DISPLAY FOR COLLEGE NOTICE BOARD
Project Title
PC CONTROLLED SCROLLING MESSAGE DISPLAY FOR COLLEGE NOTICE BOARD
Under the Guidance of
Submitted by

2. ABSTRACT
This project is designed to develop a PC controlled scrolling message display for college notice board. It can also be used to display latest information anywhere such as faculty, shop, mosque and other places. The information is transmitted using PC.
The PC is interfaced to microcontroller through MAX232 IC. An external memory is used to store the information. The information sent through PC is display on a LCD interfaced with the microcontroller. This project is based on microcontroller from 8051 family. Embedded C language is used to program this microcontroller.

3. BLOCK DIAGRAM

4. HARDWARE REQUIREMENTS
TRANSFORMER (230 – 12 V AC)
VOLTAGE REGULATOR (LM 7805)
RECTIFIER
FILTER
MICROCONTROLLER (AT89S52/AT89C51)
PUSH BUTTONS
MAX232
DB9 CONNECTOR
EEPROM IC PC
LCD
IN4007
LED
RESISTORS
CAPACITORS

5. POWER SUPPLY Bridge rectifier 5v Regulator 230 V AC 50 Hz 5V DC
Filter(470µf)
12V step down
transformer

6. It is a smaller computer Has on-chip RAM, ROM, I/O ports...
MICROCONTROLLER
It is a smaller computer
Has on-chip RAM, ROM, I/O ports...
RAM
ROM
I/O Port
Timer
Serial COM Port
Microcontroller
CPU
A single chip

7. INTERNAL STRUCTURE OF A MICRO CONTROLLER-AT89S52/51
CPU
On-chip RAM
On-chip ROM for program code
4 I/O Ports
Timer 0
Serial Port
OSC
Interrupt Control
External interrupts
Timer 1
Timer/Counter
Bus Control
TxD RxD
P0 P1 P2 P3
Address/Data
Counter Inputs

8. Features of AT89S51/52 Compatible with MCS®-51 Products
8K Bytes of In-System Programmable (ISP) Flash Memory
Endurance: 10,000 Write/Erase Cycles
4.0V to 5.5V Operating Range
Fully Static Operation: 0 Hz to 33 MHz
256 x 8-bit Internal RAM
32 Programmable I/O Lines
Three 16-bit Timer/Counters
Eight Interrupt Sources
Full Duplex UART Serial Channel
Interrupt Recovery from Power-down Mode
Watchdog Timer
Dual Data Pointer

9. Pin Description

10. MAX 232
The MAX232 is an integrated circuit that converts signals from an RS-232serial port to signals suitable for use in TTL compatible digital logic circuits.
The MAX232 is a dual driver/receiver and typically converts the RX, TX, CTS and RTS signals .
When a MAX232 IC receives a TTL level to convert, it changes a TTL Logic 0 to
between +3 and +15V, and changes TTL
Logic 1 to between -3 to -15V, and vice
versa for converting from RS232 to TTL.

11. DB9 CONNECTOR
The DB9 (originally DE-9) connector is an analog 9-pin plug of the D-Sub miniature connector family (D-Sub or Sub-D).
DB 9 PIN CONNECTOR

12. EEPROM IC

13. LED
LEDs are semiconductor devices are made out of silicon.When current passes through the LED, it emits photons as a byproduct. Normal light bulbs produce light by heating a metal filament until its white hot.
LEDs present many advantages over traditional light sources including lower energy consumption, longer lifetime, improved robustness, smaller size and faster switching

14. LIQUID CRYSTAL DISPLAY (LCD)
Most common LCDs connected to the microcontrollers are 16x2 and
20x2 displays.
This means 16 characters per line by 2 lines and 20 characters per line
by 2 lines, respectively.
The standard is referred to as HD44780U, which refers to the controller
chip which receives data from an external source (and communicates
directly with the LCD.

15. LCD BACKGROUND
If an 8-bit data bus is used the LCD will require 11 data lines
(3 control lines plus the 8 lines for the data bus)
The three control lines are referred to as EN, RS, and RW
EN=Enable (used to tell the LCD that you are sending it data)
RS=Register Select (When RS is low (0), data is treated as a command)
(When RS is High(1), data being sent is text data )
R/W=Read/Write (When RW is low (0), the data written to the LCD)
(When RW is High(1), the data reading to the LCD)

16. Working of project
This project is designed to develop a PC controlled scrolling message display for college notice board.
It can also be used to display latest information anywhere such as shop, mosque and other places. The information is transmitted using PC.
The PC is interfaced to microcontroller through MAX232 IC. An external memory is used to store the information.
The information sent through PC is display on a LCD interfaced with the microcontroller.

17. Soft ware Requirements
Keil an ARM Company makes C compilers, macro assemblers, real-time kernels, debuggers, simulators, integrated environments, evaluation boards, and emulators for ARM7/ARM9/Cortex-M3, XC16x/C16x/ST10, 251, and MCU families.
Compilers are programs used to convert a High Level Language to object code. Desktop compilers produce an output object code for the underlying microprocessor, but not for other microprocessors.

18. i.e the programs written in one of the HLL like ‘C’ will compile the code to run on the system for a particular processor like x86 (underlying microprocessor in the computer).
For example compilers for Dos platform is different from the Compilers for Unix platform  So if one wants to define a compiler then compiler is a program that translates source code into object code.

19. BIBILOGRAPHY
“The Microcontroller and Embedded systems” by Muhammad Ali Mazidi and Janice Gillispie Mazidi , Pearson Education.
ATMEL 89S52 Data Sheets.

20. QUERIES ?

21. THANKYOU