07-06-2012, 01:26 PM
PROJECT REPORT ON MULTICOLOUR LED DISPLAY
LED DISPLAY[.pdf (Size: 994.69 KB / Downloads: 132)
ABSTRACT
LED's are a fantastic way to illuminate any kind of sign, be it lettering or panels.
LED Dot-Matrix Displays are a common sight nowadays on streets, malls,
buildings, parks and other public places. It is a way of visual information where
large LCD and other display become too much expensive. The commonly seen
displays are single coloured or having 2 or 3 colours .But here multicoloured LED
display is being introduced .This project provides an efficient and scalable
approach to LED Dot Matrix displays.
INTRODUCTION
Visual impact is the most effective mode of influencing human minds which is the main aim of
adverstisements etc. A display device serves this purpose.A display device is a device for presentation of
information for visual or tactile reception, acquired, stored, or transmitted in various forms. The display
devices used to display information on machines, clocks, railway departure indicators and many other
devices require a simple display of limited resolution. The display consists of a matrix of lights or
mechanical indicators arranged in a rectangular configuration (other shapes are also possible, although
not common) such that by switching on or off selected lights, text or graphics can be displayed. Various
modifications has been made in the display board.
OBJECTIVE
Display technology pervades all aspects of present day life, from televisions to automobile
dashboards to laptop computers to digital cameras. Single coloured LED display boards are very
common nowadays. The same yellow or red coloured board is not attractive .The introduction of
multicoloured LEDs into the display boards make them attractive. This project is oriented towards the
development of a prototype of a multicoloured LED display board which is being controlled by an LED
driver. The use of multicolour LED opens door to many applications. The display board is made on
readily available components. The important requirement is that the display board should have long life
expectancy, high tolerance to humidity, low power consumption and minimal heat generation. The
fundamental part is a 4X4 LED module which could be repeated column wise or row wise to enlarge the
display without any change in circuitry. Both single line and double line display could be affected.
Motivation towards the project was to make available a readily expandable multicolour display board
which can be used for multiple purposes.
LED Matrix
A 4X4 LED module is the fundamental part of the display. LED display panels use matrix addressing
techniques to organize the light emitting elements or pixels into a number of rows and columns with each
pixel at an intersection of a particular row and a particular column. A light emitting device (LED) display is
typically supplied with data addressed from graphical memory location in accordance with a column-major
display. The LED display illuminates pixels on a column basis by providing sourcing and sinking currents to
diodes in the display. An LED display is typically made up of various dots arranged in a matrix pattern
having rows and columns. The dots are usually called pixels where the pixels are made up of several LEDs.
Illuminating the pixel requires activating an intersecting row and column thereby providing a closed
current path that includes the pixel to be illuminated.
LED Array
It consists of 16 multicoloured LEDs arranged in 4x4 matrix format. The LED used is LED 339-1VRKGBBW-
1 from ever bright. It is a multicoloured common cathode led with 2 Blue LEDs, 1 Green and 1 Red LED. It
has 6 pins: 2 Blue Anodes & their common cathode, 1 Green and 1 Red anode & their common cathode.
Blue LEDs have lower brightness compared to Red/Green, so there are 2 Blue LEDs in this package.
Multicolour LED provides primarily blue, green, yellow colour by giving bias to appropriate pins.
