http://www.projectsof8051.com/projects/06-rolling-display-using-matrix-leds.html
Description:
This project can be used for Advertising
or for providing information at various places like shops, government offices, hospitals, railway stations. The
Rolling display is prepared using 5 X 7 Matrix LEDs which means LEDs
are arranged in a pattern consisting of 5 columns and 7 rows. A matrix
of 5 X 7 LEDs contribute to a single character. Here we have used 6
characters which means 6 matrices. The actual physical diamension of
single matrix is 10 cm by 8 cm, so diamension of complete display is 10
cm by 48 cm. A keypad used to select which message has to be displayed.
These messages are stored in a EEPROM. PC interfacing is used for
sending data to computer.
Block Diagram:
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Circuit Diagram:
Click
here to view the circuit diagram of the project |
Description in
detail:
It mainly consist of following blocks
1. 5 x 7 Matrix LEDs: We have to display
characters in
the messages, for this purpose we are going to use 5 X 7 matrix of
LEDs. A single matrix consists of 5 columns and 7 rows. We have used
5mm Red LEDs. The actual physical diamension of single matrix is 10 cm
by 8 cm.
2. Control Unit: This unit is used to select the
matrices sequentially, control unit gets input from Microcontroller and
then gives output to individual matrix. Only one matrix is selcted at a
time so as to display a character.
3. Microcontroller: This is the CPU (central
processing unit) of our project. We are going to use a microcontroller
which belongs to the 8051 family. The various functions of
microcontroller are like
I. Reading input from Keypad and store it into EEPROM II. Sending data
to Data bus so that it displays characters on the Matrix. III. Storing
the data into EEPROM memory and display it later using Matrix.
IV. Sending the data to the computer
using serial port
4. EEPROM: We are going to use EEPROM memory, it
is
Electrically erasable programmable read only memory. It stores the data
even if power supply is disconnected. This is used to the characters
which has to be displayed on the Matrix display.
5. PC Interfacing: We are going to use max 232
IC for pc interfacing, the values of message to be diplayed on Matrix
LEDs will be sent to PC.
6. Keypad: Various operations of keypad are as
following,
I. Start / Stop display.
II. Select message to be displayed.
III. Send/Receive data to Computer
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