Propeller Display Of Message By

Virtual Leds

http://www.edgefxkits.com/

Propeller Display Of Message By Virtual Leds

Introduction

Propeller is a term associated with a circular rotating object. As this needs to

rotate whole circuit assembly, there must be some prime mover attached to it. So,

the term ‘Propeller’ is used.

It uses bright light emitting diodes for displaying the characters and symbols on

its assembly. propeller led display is the right name given to this project.

It is the phenomenon which is related to vision capability of the human eye by

which an afterimage is thought to persist for approximately 1/25th of a second.

http://www.edgefxkits.com/

Propeller Display Of Message By Virtual Leds

So, if someone is observing the images at a rate of 25 images per second,

then they appear to be continuous.

Propeller runs on a single battery with wall adapter facility.

The best example of this property is the red circle we observe when we

rotate the firecracker or incense stick in a circle.

http://www.edgefxkits.com/

Propeller Display Of Message By Virtual Leds

Block Diagram

http://www.edgefxkits.com/

Propeller Display Of Message By Virtual Leds

Working

Propeller Display of Message comprises of the circular display of a string

of LEDs.

LED string mounted on a printed circuit board are duly interfaced to a

microcontroller by using a high-speed motor and some mechanical

assembly.

An appropriate program while executed drives a pair of a single line LEDs

in space multiplexing mode.

It displays some message and or a clock timing taking advantage of

persistence of vision of the human eye.

http://www.edgefxkits.com/

Without the single line of LEDs in space multiplexing mode if one would have

to display a message, number of LEDs as high as 525 would have been used.

The synchronizing is be implemented through software.

Propeller Display Of Message By Virtual Leds

http://www.edgefxkits.com/

Propeller Display Of Message By Virtual Leds

Hardware Requirements

Microcontroller, Sensors.

Resistors, Capacitors, Diodes.

Transformer, Voltage Regulator.

Transistors, Leds.

High Speed Motor.

http://www.edgefxkits.com/

Propeller Display Of Message By Virtual Leds

Software Requirements

Keil compiler

Language: Embedded C or Assembly.

http://www.edgefxkits.com/

Power Supply

Propeller Display Of Message By Virtual Leds

http://www.edgefxkits.com/

Propeller Display Of Message By Virtual Leds

The 230V AC supply is first stepped down to 12V AC using a step-down

transformer.

It is then converted to DC using the bridge rectifier.

The AC ripples are filtered out by using a capacitor and given to the input

pin of the voltage regulator 7805.

At output pin of this regulator, we get a constant 5V DC which is used for

MC and other ICs in this project.

http://www.edgefxkits.com/

Propeller Display Of Message By Virtual Leds

Features Of Microcontroller

8K Bytes Of In-system Programmable (ISP) Flash Memory

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

http://www.edgefxkits.com/

Bob Blick's Propeller Clock Project

Bob Blick made the clock spinning on a piece of perf board.

The power is provided from the spinning armature of a plain DC motor.

But this Project has not got viability though Bob was Successful in

Displaying the Numeric Digit on a propeller Display.

Propeller Display Of Message By Virtual Leds

http://www.edgefxkits.com/

Propeller Display Of Message By Virtual Leds

Applications

Applications can find their way to cost effective solutions for large public

displays, information systems.

It can directly replace Railway station information displays, bus stands

and many more places.

http://www.edgefxkits.com/

Future scope

Can be integrated with GSM such that ANY Message from the End-user

with a phone can display the text by merely sending SMS.

It can be made possible to display the clock RTC on the display.

Propeller Display Of Message By Virtual Leds

http://www.edgefxkits.com/

Propeller Display Of Message By Virtual Leds