1. PROPELLER DISPLAY OF MESSAGE BY VIRTUAL LEDS
Submitted By:

2. ABSTRACT
This project comprises of circular display of a string of LEDs.
Using a high speed motor and some mechanical assembly, LED string mounted on a printed circuit board.
This displays some message and or a clock timing taking advantage of persistence of vision of human eye.

3. BLOCK DIAGRAM

4. HARDWARE REQUIREMENTS
Microcontroller, sensors.
Resistors, Capacitors, Diodes.
Transformer, Voltage Regulator.
Transistors, LEDs.
High Speed Motor.

5. Power supply

6. Contd..
The 230V AC supply is first stepped down to 12V AC using a step down transformer.
This is then converted to DC using bridge rectifier.
The AC ripples is filtered out by using a capacitor and given to the input pin of 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.

7. 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

8. Block diagram of mc 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

9. Features of MC 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

10. Pin description

11. BOB BLICK'S PROPELLER CLOCK PROJECT
Bob Blick made the clock spinning on a piece of perfboard.
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.

12. IMAGE OF BOB BLICK’S PROPELLER DISPLAY

13. BASIC PRINCIPLE OF THE PROJECT
POV (Persistence Of Vision):
This is the phenomenon which is related to vision capability of human eye
By which an after- image is thought to persist for approximately 1/25th of a second.
So, if someone is observing the images at a rate of 25 images per second then they appear to be continuous

14. SCHEMATIC DIAGRAM EXPLANATION
Please Refer CD

15. …..contd As 8051 Series Has only one set of UART
(TX and RX) it is essential to use a multiplexer.
By using 4052 we can Switch the TX and RX pins of microcontroller to be connected to GSM and GPS.
The data gets Received From The Gps Module by the microcontroller and Simultaneously Transmits the same through GSm Modem

16. Software 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 8051 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.

17. Contd..
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.

18. schematic
Please Refer CD

19. Working of project
Please Refer CD

20. Applications
Applications can find their way into cost effective solutions for
large public displays, information systems.
It can directly replace Railway station information displays, bus stands and many more places. 

21. Future scope
Can be integrated With GSM Such that ANY Message from the End user with a phone can Display The text by simply Sending SMS.
It Can be Made possible to Display the clock RTC on the Display.

22. Conclusion