This document describes a propeller LED display system using an AT89S52 microcontroller. It consists of an IR sensor, DC motor, motor driver circuit, LEDs, and other components. The system works on the principle of persistence of vision, where the eye retains images flashed at 25 Hz, appearing as continuous motion. The microcontroller controls the motor speed and LED patterns to produce a propeller-like visual effect. The document also provides details about the hardware components and microcontroller architecture.

3. BLOCK
DIAGRAM

4. IR
SENSO
R
8
9
S
5
2
L
E
D
A
R
R
A
Y
DC MOTOR
DRIVER
CURCUIT
DC
MOTO
R

5. Circuit LEDs
MOC7811
Construction
5V GND

6. Introduction
What is Propeller LED Display???
Propeller is a term generally associated
with rotating fan , revolving at high RPM.
Just like a propeller, this is a special kind of
a rotating display.
How it works???
PERSISTANCE OF VISION
This is a phenomenon of the eye by which
an afterimage is thought to persist for
approximately 1/25th of a second. So if
someone is observing images at rate of 25
images/second, they appear to be
continuous.
Confused???

7. A picture is worth a thousand words…..

8. System Requirement
A. Hardware Used:
1. Microcontroller AT89S52
2. IR Pair (IR LED AND
PHOTO DIODE )
3. Voltage Regulator
4. DC Motor
5. Motor Driver Circuit

9. MCROCONTROLLER
AT89S52
The AT89S52 is a low-power, high-performance
CMOS 8-bit microcontroller with 8K bytes of in-system
programmable Flash memory. The
device is manufactured using Atmel’s high-density
nonvolatile memory technology and is
compatible with the industry- standard 80C51
instruction set and pin OUT before it can be
programmed again. This led to introduce FLASH
and NV-RAM versions of 8051.

10. The micro-controller generic part number
actually includes a whole family of
microcontrollers that have numbers
ranging from 8031 to 8751 and are
available in N-channel Metal Oxide Silicon
(NMOS) and CMOS construction. 89c52 is
an 8-bit micro-controller having 40 pins
arranged as DIP packages. The features
unique to micro-controllers include:

11.  INTERNAL RAM AND ROM
 I/O PO RTS WITH PROGRAMMABLE PINS
 TIMERS AND COUNTERS
 SERIAL DATA COMMUNICATION

 The 89C52 architecture consists of these specific features:
 Eight-bit CPU with registers A and B
 16-bit program counter and data pointer
 8-bit stack pointer
 Internal ROM of 8k
 Internal RAM of 128 bytes
 Four register banks each containing eight registers
 16 bytes addressable at the bit level
 80 bytes of general purpose data memory
 32 input/output pins arranged as four 8 bit ports
 Three 16-bit timer/counter
 Full duplex serial data receiver/transmitter
 Control registers: TCON, TMOD, SCON, PCON, IP and IE
 Two external and three internal interrupt sources
 Oscillator and clock circuits

12.  )

 As its name implies it is a diode, which emits light when
forward biased. Charge carrier recombination takes place
when electrons from the N-side cross the junction and
recombine with the holes on the P side. Electrons are in the
higher conduction band on the N side whereas holes are in
the lower valence band on the P side. During recombination,
some of the energy is given up in the form of heat and light. In
the case of semiconductor materials like Gallium arsenide
(GaAs), Gallium phoshide (Gap) and Gallium arsenide
phoshide (GaAsP) a greater percentage of energy is released
during recombination and is given out in the form of light. LED
emits no light when junction is reverse biased.

13. 
 Definition: -
 The transformer is a static electro-magnetic device that
transforms one alternating voltage (current) into another
voltage (current). However, power remains the some during
the transformation. Transformers play a major role in the
transmission and distribution of ac power.
 Principle: -
 Transformer works on the principle of mutual induction. A
transformer consists of laminated magnetic core forming the
magnetic frame. Primary and secondary coils are wound upon
the two cores of the magnetic frame, linked by the common
magnetic flux. When an alternating voltage is applied across
the primary coil, a current flows in the primary coil producing
magnetic flux in the transformer core. This flux induces
voltage in secondary coil.

14. A photodiode is a type of photo detector
capable of converting light into
either current or voltage, depending upon
the mode of operation. The common,
traditional solar cell used to generate
electric solar power is a large area
photodiode.

15.  :

 1. Keil u-Vision: To Write the microcontroller program.
 The C programming language is a general-purpose
programming language that provides code efficiency, elements
of structured programming, and a rich set of operators. C is
not a big language and is not designed for any one particular
area of application. Its generality combined with its absence of
restrictions, makes C a convenient and effective programming
solution for a wide variety of software tasks. Many applications
can be solved more easily and efficiently with C than with
other more specialized language

16. The Cx51 Optimizing C Compiler is a complete implementation of the
American National Standards Institute (ANSI) standard for the C language .
Cx51 The Compiler provides you with the flexibility of programming in C and
the code efficiency and speed of assembly language . 2.PRO51
Programmer Software: To load the program in microcontroller.
3. PCB Artist: To design the PCB of the project.

17. THANK YOU