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BHARATI VIDYAPEETH’S
COLLEGE OF ENGINEERING FOR WOMEN
CERTIFICATE
This is to certify that
"PROPELLER LED DISPLAY"
Submitted by
NAWALE TEJASHREE L. (ROLL NO. 46)
SHINDE SUPRIYA S. (ROLL NO. 52)
TIWARI NEHA D. (ROLL NO. 47)
Of T.E. (Electronics and Telecommunication Engineering) is a bonafide work carried out by
her under the supervision of Prof. M. S. Kasar and it is approved as the partial fulfillment of
Mini Project & Seminar as per the syllabus of the University of Pune.
Prof. M. S. Kasar Prof. S. T. Khot
Guide Head,
Department of E&TC Department of E&TC
Place: Pune
Date:
A
PROJECT REPORT
ON
"PROPELLER LED DISPLAY"
PRESENTED BY
NAWALE TEJASHREE L.
SHINDE SUPRIYA S.
TIWARI NEHA
GUIDED BY
Prof. M. S. Kasar
DEPARTMENT OF ELECTRONICS AND TELECOMMUNICATION ENGINEERING
BHARATI VIDYAPEETH’S
COLLEGE OF ENGINEERING FOR WOMEN
PUNE 411043
APRIL 2011
ACKNOLEDGEMENT
First, we would like to express our best regards to our project guide Prof. M.S.Kasar,
whose valuable guidance, encouragement, and provision of necessary facilities made this work
possible.
We are also thankful to our respected Head of the Department Mrs. S.T.Khot whose
help and shared knowledge was the main support to complete our project. Many thanks are owed
to our classmates for their useful discussion and timely suggestions. Their technical support and
encouragement helped us to finalize our project.
Our special thanks to Mr. S.H. Deshmukh who helped us a lot through the problems we
came across. We are absolutely grateful to all non-teaching staff for their assistance which is key
factor behind our success. We would also like to express our gratitude towards the college for
providing us with the best facilities and proper environment to work on our project.
Finally we offer our great thanks and regards to our family for their support which helped
us through the difficulty and hardships of life to earn this achievement.
Project Team
Ms. Nawale Tejashree L.
Ms. Shinde Supriya S.
Ms. Tiwari Neha D.
CONTENTS
CHAPTER TITLE PAGE NO.
1 INTRODUCTION 1
2. SPECIFICATIONS 2
2.1 CIRCUIT SPECIFICATION 2
2.2 ELECTRICAL SPECIFICATION 2
2.3 MECHANICAL SPECIFICATION 2
3. LITERATURE SURVEY 3
4. BLOCK DIAGRAM 5
4.1 BLOCK DIAGRAM DESCRIPTION 6
5. MODULE WISE DESIGN 7
5.1 INTERRUPT MODULE 9
5.2 SPEED OF LEDS 10
5.3 MICROCONTROLLER REACTANCE
TIME
11
5.4 POWER SUPPLY 12
6. MECHANICAL ASSEMBLY 13
7. CIRCUIT DIAGRAM 14
7.1 WORKING 15
8. ALGORITHM 16
9. FLOWCHART 17
10. PROGRAM 18
11. PCB LAYOUT 25
11.1 PCB MAKING 26
11.2 STEPS FOR PCB DESIGNING 27
11.3 ASSEMBLY OF COMPONENTS ON PCB 27
12. TROUBLESHOOTING MANNUAL 27
13. BILL OF MATERIALS 28
14. ADVANTAGES 30
15. APPLICATIONS 30
16. RESULT AND CONCLUSION 31
17. FUTURE SCOPE 34
18. REFRENCES 35
INTRODUCTION
This project is a special kind of circular LED display. With the help some mechanical
assembly, LED count, hardware requirement, and hence overall cost is cut to very affordable
price. Also, maintenance and repairing of the display is so easy, that anyone having a little
electronics knowledge can take care of this. All the synchronizing can be implemented through
software.
First of its kind, made using the 40-pin 8051 series microcontroller, this project use the
principle of Space Multiplexing. This propeller display is mechanically scanned and displays the
characters in digital format. Made from scrap it can be used anywhere and everywhere and the
most amazing fact about this display is its crystal clear display. This display consists of just 8
bright LEDs which are rotated to show the display.
For building this project, requirement is just a small 40 pin microcontroller, a position
encoder, and LEDs. This display can show the messages, which will require a whopping 525
LEDs. So hardware and cost minimization is achieved.
SPECIFICATIONS
SPECIFICATION OF THE SYSTEM:
8-bit microcontroller AT89V51RD2 with flash program memory. Interrupt sensor MOC 7811. DC motor with 1975 RPM. +5V power supply using IC 7805.
SPECIFICATION:
MICROCONTROLLER AT89V51RD2: 64KB flash program memory. 1Kb of data RAM. 5V operating voltage from 0 to 40 MHZ. Four 8-bit I/O ports with three high-current port 1 pins (16Ma each). Support 12 clock or 6-clock mode selection via software or ISP.
INTERRUPT SENSOR (MOC 7811): Photo Gap Detector Output Circuit Type=Transistor Mounting hole diameter: 3mm Mounting hole spacing: 19mm Slot width: 3mm Slot depth: 7mm I (F) Max. (A) Forward Current=50mA I(O) Max.(A) Output Current=1.9mA
DC MOTOR: Tape recorder motor. Input voltage: + 12v. Current capability: 750mA RPM: 1975/min
ELECTRICAL SPECIFICATION : Fixed regulated power supply. Output voltage rating: +12V. Short circuit protection.
MECHANICAL SPECIFICATION:
PCB size: 8cm x 5cm
Enclosure size: 18cm x 10cm
LITERATURE SURVEY
The reference support that the circuit diagram and other related information taken from
website:
1. http://www.luberth.com/analog.htm
2. http://www.jogy.ch/files/Circuit_Cellar_Design_Contest_H3210/
Propeller_Display.pdf
3. http://www.8051projects.net/comment-n153.html
4. http://www.circuitlake.com/propeller-128-light-contoller.html
5. http://www.gadgetgangster.com/news/45-designer-news/290-led-matrix-displays-
with-the-prop.html
BLOCK DIAGRAM
Basic blocks of PROPELLER LED DISPLAY are:
1. Interrupter Module
2. Microcontroller
3. LED module
4. DC motor
5. DC power supply
Interrupter Module
Microcontroller
LEDDispl
ay
IRSenso
r
BeamInterru
ptIn eachrevoluti
on
DCmotor
DC Regulated
power supply
Interrupter module is our sensor module, consisting of the IR interrupt sensor MOC7811, from
Motorola Inc. This sensor was selected from a variety of other alternatives, because of its small
size, precise interrupt sensing, and sturdy casing.
One great advantage of using this module is, interfacing it with the microcontroller is
just a matter of two resistors and a general purpose transistor.
Microcontroller AT89V51RD2
This project is based around the microcontroller AT89V51RD2, which is a derivative of
8051 family, from Atmel Inc. This is a 40 pin IC packaged in DIP package. This small sized IC
is used, mainly because of its reduced weight. This improves the performance of the display,
because reduced weight gives advantage of increased RPM.
LED MODULE
LED module consisting of 8 bright LED is fixed in another side of the arm of our project.
These LEDs are connected with each of the port pin of microcontroller, with a series current
limiting resistor of 470 ohm.
DC Motor
Repeated scanning of the display is must for continuous vision. This task is achieved
using circular rotation of the whole circuit assembly. So, we used a DC motor as the prime
mover.
DC Power Supply
For microcontroller, as well as the DC motor, a regulated DC power supply is required.
We have to provide +5V to the microcontroller, while +12V to the motor.
MODULEWISE DESIGN
INTERRUPT MODULE
This device has a compact construction where the emitting-light sources and the detectors are located face-to-face on the same optical axis. The operating wavelength is 950 nm. The detector consists of a phototransistor.
FEATURES
Compact construction No setting efforts Polycarbonate case protected against ambient light 2 case variations 3 different apertures
INTERRUPT SENSOR DIAGRAM
CIRCUIT DIAGRAM:
R1:
R1 is dimensioned that on the sender a current of about 15mA flows.
R1=5V – Vled / I led
=5V- 1.6V/ 15mA
= 227Ω
An available value is 220Ω.
R2:
By testing different values I discovered an optimal value of 1kΩ.
Rc, Rb:
Rb limits the base current of the transistors. Rc sets the output current which this circuit can
deliver. On the microcontroller the input resistance of a pin is very high, i take a value of 10kΩ.
Now we can calculate the collector current.
I C=5V/Rc
=5V/10k Ω
=500µ A
The gain of the transistor 2N3904 with a collector current of 500μA is about 300.
We can calculate the required base current now.
I B= I C/β
=500µA/200
=1.6µA
Basis resistor Rb:
Rb=5V/I B
=5V/1.6µA
=3.1 MΩ=310 kΩ
To bring the transistor to saturation for Rb we are selecting value of 310 kΩ.
SPEED OF LEDS (FRAME RATE)
The rotational speed of the LED's affects directly how many pictures can be displayed in
a second. This corresponds to the frame rate.
On a modern TV, the frame rate is 100Hz. The more frame rate, the less flickering of the
picture.
Because on the Propeller Display the picture is scanned mechanically, it is not easy to
achieve high frame rates. For me it isn't possible to mechanics that can rotate the LED's
100 times a second.
The propeller has to be very well balanced to keep vibrations as low as possible and keep
the speed of the rerating LED's as high as possible.
How fast are the LED's when a picture is displayed with a frame rate of 25Hz?
Here is the Calculation.
Acceptance:
f = 25Hz (Frame rate)
r = 20cm (Radius from centre of rotation to the LED's)
u=2 ⋅ r⋅π=2⋅0.2m 3.141=⋅ 1.256m
v= f ⋅u 3600=25⋅ ⋅1.256m 3600=113.040⋅ m/h
=113.04 Km/h.
Acceptance:
f = 25Hz (Frame rate)
r = 6 cm (Radius from centre of rotation to the LED's)
u=2⋅r ⋅π=2⋅0.06m 3.141=⋅ 0.3769m
v= f ⋅u 3600=25⋅ ⋅0.3769m 3600=33921m/h⋅
=33.921km/h
We see that already a slow frame rate of 25Hz generates very high speeds on the LED's. The
bigger the radius of the display, the bigger is the speed and more vibrations accure.
MICROCONTROLLER:
Required reaction time of the microcontroller
Depending of the rotational speed of the LED's and the resolution of the display the
Microcontroller has to be quick enough to switch the LED's on and off in an acceptable time.
Here is a calculation of the minimum, the microcontroller has to react.
Acceptance:
f = 25Hz (25 frames in a second)
r = 6cm => u = 0.3769m
ILED = 5mm (Vertical distance between the LED's)
In order that a nice clean picture is originated, the horizontal and vertical distance from pixel to
pixel or LED to LED should be the same.
We calculate the number of displayable pixels on the horizontal axis.
PixelCountHorizontal = u/lLED
=0.3769/0.005m
=75.3 ≈ 76
The most speed of the microcontroller is needed when a LED is toggled every time. This
Corresponds to a bit pattern of 101010101... When this bit pattern can be displayed, every
Other bit pattern/picture can be displayed without problems.
POWER SUPPLY:
5V Regulator
For the 5V supply i took a LM7805 fixed 5V regulator. Beside the regulator itself some
Capacitors at the input and output are required. The values of the capacitors are taken from the
datasheet.
Maximal output current is 1A.
Min Input for 7805 is
= Drop across IC 7805 + Required Output voltage
= 3 V+ 5V
= 8
So at Input of 7805 we required 8 V with margin.
So we are using +9V battery to supply power to the circuitry.
MECHANICAL ASSEMBLY
Mechanical assembly plays a vital role in proper functioning of this project. The display is
scanned each time, by rotating the whole assembly in a circular path. The basic idea we
developed is on our own, by implementing and modifying different ways to do this.
Following diagram shows the most reliable way, that we finally selected.
Here, one major challenge was how to bring +5V supply to the spinning circuit. We
tried the same by adopting two-three different methods, but finally concluded on the method, as
shown in the figure.
As seen in the diagram, one supply connection (GND) is provided
through the motor’s shaft. Other terminal (Vcc) is connected, by arranging a friction disc-brush
arrangement. The brush keeps its contact with the disc, so that current can be supplied.
Most critical objective was to achieve pristine balance and overall good mechanical
strength. For weight adjustment, we have provided one long screw, and weight can be attached
or removed by adding / removing metallic bolts. If the assembly is balanced perfect, then it can
achieve stability, and rotate at high RPMs too. This will improve the overall efficiency of this
display.
CIRCUIT DIAGRAM
MOC7811
Circuit
5V 12V
GND
CIRCUIT DISCRIPTION:
The circuit diagram is mainly consisting of three parts and these are as follows:
1. Interrupt module2. LED module 3. Microcontroller
In our circuit diagram interrupt module is used for synchronization purpose, and it requires +5V
power supply. We use IC MOC 7811 as a position encoder as its sensing power is high as
compare to other IC's. And output of interrupt module is taken from collector of 2N3904
transistor and connected to pin INT0 of microcontroller. The transistor 2N3904 is NPN
complimentary type transistor to invert output of MOC7811 sensor.
Microcontroller is heart of our circuitry. The output of interrupt module circuit is given to
INT0 pin of port 3. Port 1 is used as output port. LED is connected from port 1.0 to port1.7. We
use a foldable metal strip to provide an external interrupt to microcontroller.
An interrupt module consists of IR LED and Photodiode mounted facing each other
enclosed in plastic body. When light emitted by the IR LED is blocked because of some
completely opaque object, logic level of the photo diode changes. As we provide power supply
to DC motor, it starts to rotate and when the strip passes through the sensor then it gives the 0V
at output. The output of sensor is +5V when there is no interrupt. According to an external
interrupt the microcontroller decides to ON and OFF of the LED's.
SOFTWARE DESIGN
ALGORITHM
1. Start.
2. Load proper value in IE register, so that the interrupts INT0 and T0 are enabled. (IE
= 83H)
3. Offer higher priority to the INT0 (External) interrupt. (IP = 01H)
4. Configure timer 1 as 16-bit timer, and timer 0 as 8-bit auto reload mode timer.
( TMOD = 12H)
5. INT0 should be configured as edge interrupt. (IT0 = 1)
6. Configure port 3 as input port. (P3 = 0FFH)
7. Measure period of one revolution with T0
8. Stop the timers
9. Move th1 and tl1 into convenient registers.
10. Divide this 16 bit value by our total number of segments
11. Subtract the answer from 256, and load the result in th0.
12. After each timer overflow interrupt, display next value from look up table.
13. Start the timers.
14. Return from interrupt. Go to step 7.
FLOW CHART
Measure period of one revolution with T0
Load the result in T1 with auto reload mode.
Divide by 120
After each timer overflow interrupt, display next value
from lookup table
START
CODE
; $include (reg51.inc)
; T0 interrupt
Org 000h
Ajmp main
Org 000BH
Acall interr
Mov p3, #0ffH
RETI
; EXT0 interrupt
Org 0003H
Acall interr1
RETI
Org 230h
Lookup:
DB
10000010b,01111100b,01111100b,01111100b,10000010b,11111110b,1011110b,000000
00b,11111100b,11111110b,10111100b,01110010b,01110100b,01101100b,10011100b
DB
01111010b,01111100b,01011100b,00101100b,01110010b,11100110b,11010110b,10110
110b,00000000b,11110110b,00001100b,01101100b,01101100b,01101100b,01110010b
DB
10000010b,01101100b,01101100b,01101100b,11110010b,00111100b,01111010b,01110
110b,01101110b,00011110b,11100000b,00001100b,01101100b,00001100b,11100000b
DB
10011110b, 01101100b, 01101100b, 01101100b, 10000010b
Org 285h
DB
10000000b,01101110b,01101110b,01101110b,10000000b,00000000b,01101100b,01101
100b,10001100b,11110010b,10000010b,01111100b,01111100b,01111100b,01111100b
DB
01111100b,00000000b,01111100b,01111100b,10000010b,00000000b,01101100b,01101100b,01111100b,01111100b,00000000b,01101110b,01101110b,01111110b,01111110b
DB
00000000b,01111100b,01101100b,01101100b,01100000b,00000000b,11101110b,11101
110b,11101110b,00000000b,11111110b,01111100b,00000000b,01111100b,11111110b
DB
11111010b,01111100b,00000010b,01111110b,11111110b,00000000b,11101110b,11010
110b,10111010b,01111100b,00000000b,11111100b,11111100b,11111100b,11111100b
DB
00000000b,01111110b,11001110b,01111110b,00000000b,00000000b,10011110b,11101
110b,11110010b,00000000b,00000000b,01111100b,01111100b,01111100b,00000000b
DB
00000000b,01101110b,01101110b,01101110b,10011110b,10000010b,01111100b,01110
100b,01111000b,10000000b,00000000b,01101110b,01100110b,01101010b,10011100b
DB
10011000b,01101100b,01101100b,01101100b,10110010b,01111110b,01111110b,00000
000b,01111110b,01111110b,00000000b,11111100b,11111100b,11111100b,00000000b
DB
00000110b,11111010b,11111100b,11111010b,00000110b,00000010b,11111100b,11110
010b,11111100b,00000010b,00111000b,11010110b,11101110b,11010110b,00111000b
DB
00111110b,11011110b,11100000b,11011110b,00111110b,01111000b,01110100b,01101
100b,01011100b,00111100b,11111111b,11111111b,11111111b,11111111b,11111111b,
; Main Function
Org 0100h
Main:
Mov ie, #83H
Mov ip, 01H
Mov tmod, #12H
Mov th0, #00h
Mov tl0, #00h
Setb it0
Mov p3, #0FFh
Acall ramc
Mov th1, #00h
Mov tl1, #00h
Setb tr0
Setb tr1
Here: ajmp here
Interr: T0 interrupt
Cjne r6, #0ffh, sk
Mov r6, #00h
Acall disp
Sjmp sk1
sk:
Mov r6, #0ffh
sk1:
Clr tf0
RET
; EXT0 interrupt
interr1:
Clr tr1
Clr tr0
Mov a, th1
Mov r1, a
Mov a, tl1
Mov r0, a
Mov r3, #00h
Mov r2, #160
Acall div16_16
Mov a, r2
Subb a, 0ffh
Mov th0, a
Mov tl0, a
Mov th1, #00h
Mov tl1, #00h
Setb tr1
Setb tr0
Mov r0, #23h
Mov r5, #00h
Mov r6, #00h
RET
ramc:
Mov dptr, #600h
Mov r7, #30
Mov r0, #40h
loop1:
Mov a, r7
Subb a, #01h
Movc a,@a+dptr
Mov @r0, aDec r0Djnz r7, loop1RET
disp:
Cjne r5, #5, continue Mov a,@r0 Cjne a, #'[', space Mov p1, #11111111b Sjmp cont Space: Mov p1, #11111110b Cont: Inc r0 Mov r5, #00h Ajmp neglect
continue: Mov a,@r0 ; moves ASCII from RAM to R0 Clr c Subb A, #30h Mov b, #05 ; ASCII to address conversion Mul AB Mov dptr, #230h Add a, r5 ; Memory offset Movc A,@A+DPTR Mov p1,a Inc r5
neglect: RET Org 600h
Msg: DB 'PROPELLER [DISPLAY [[[[[[[[[[[[[[[[[[[[',0
div16_16: CLR C ; Clear carry initially
MOV R4, #00h ; Clear R4 working variable initially
MOV R5, #00h ; Clear R5 working variable initially
MOV B, #00h ; Clear B since B will count the number of left-shifted
bits
div1:
INC B ; Increment counter for each left shift
MOV A, R2 ; Move the current divisor low byte into the accumulator
RLC A ; Shift low-byte left, rotate through carry to apply highest bit to
high-byte
MOV R2, A ;Save the updated divisor low-byte
MOV A, R3 ; Move the current divisor high byte into the accumulator
RLC A ; Shift high-byte left high, rotating in carry from low-byte
MOV R3, A ; Save the updated divisor high-byte
JNC div1 ; Repeat until carry flag is set from high-byte
div2: Shift right the divisor
MOV A, R3 ; Move high-byte of divisor into accumulator
RRC A ; Rotate high-byte of divisor right and into carry
MOV R3, A ; Save updated value of high-byte of divisor
MOV A, R2 ; Move low-byte of divisor into accumulator
RRC A ; Rotate low-byte of divisor right, with carry from high-byte
MOV R2, A ; Save updated value of low-byte of divisor
CLR C ; Clear carry, we don't need it anymore
MOV 07h, R1 ; Make a safe copy of the dividend high-byte
MOV 06h, R0 ; Make a safe copy of the dividend low-byte
MOV A, R0 ; Move low-byte of dividend into accumulator
SUBB A, R2 ; Dividend - shifted divisor = result bit (no factor, only 0 or 1)
MOV R0, A ; Save updated dividend
MOV A, R1 ; Move high-byte of dividend into accumulator
SUBB A, R3 ; Subtract high-byte of divisor (all together 16-bit subtraction)
MOV R1, A ; Save updated high-byte back in high-byte of divisor
JNC div3 ; if carry flag is NOT set, result is 1
MOV R1, 07h ; otherwise result is 0, saves copy of divisor to undo subtraction
MOV R0, 06h
div3:
CPL C ; Invert carry, so it can be directly copied into result
MOV A, R4
RLC A ; Shift carry flag into temporary result
MOV R4, A
MOV A, R5
RLC A
MOV R5, A
DJNZ B, div2 ; now count backwards and repeat until "B" is zero
MOV R3, 05h ; Move result to R3/R2
MOV R2, 04h ; Move result to R3/R2
RET
END
PCB LAYOUT
PCB LAYOUT/ART WORK DESIGN
PRINTED CIRCUIT BOARD
Much modern electronic system would be virtually impossible to package without incorporating
printed circuit board. A printed circuit board popularly known as PCB, is a piece of plastic
insulating board, on one side of which a complete layout diagram of an electronic circuit
consisting of copper as conductive layer is printed by a special photo generation process. On the
other side of PCB are mounted electronic components like capacitor, resister, inductor and IC's.
The metal conducting part serves as conducting medium for the electronic components that are
assembled on the opposite side of board.
PCB MAKING
Take proper scale of components and according to such scale make component lay out of project
circuit, on a paper. This layout is simple as well as small in size. Then draw mirror image of PCB
layout.
ARTWORK (PAINTING AND DRILLING)
Take copper clad board of required size and transfer mirror image layout on board. Drill for the
connection on proper track. Using the paints i.e. the mirror images drawn by mirror do the
painting. After some time check whether the paintings is in proper alignment with rack and if in
case there is any fault then correct it. Take solution of FeCI3 in port and dip PCB in solution for
some hours. After some time remove PCB from solution we see that the copper is removed from
copper clad board except that copper, which is painted.
STEPS FOR PCB DESIGNING
The following checklist uses the major area of concern in the process of PCB design:
a) Optimum size and shape of board should be ensured.
b) The substrate should be selected properly by taking into consideration its cost, mechanical
properties and electrical properties.
c) Layout of conductor pattern should be taken care from cross talk, leakage, shielding, numbers
of jumpers required and their placement.
d) Selection of conductor width, thickness and spacing should be done after analyzing their
placement.
e) Proper productive coating should be selected.
f) Thermal consideration should be analyzed properly.
g) Proper mounting of heavy and unstable component should be ensured.
h) Easy maintainability should be built in.
SIZE AND SHAPE
The size and shape of PCB is compromise among the many parameters. The maximum
size of board is determined by the available facility, like the wave soldering station, cleaning
lank, component assembling unit etc. When the board size is big and many components have
to be mounted on it, the probability of the failure of the board increases. Troubleshooting large
board increases. Smaller PCB's uses more connector; more back panel wiring, which can be
problematic due to bad contacts.
ASSEMBLY OF COMPONENTS ON THE PCB
Care has to be taken while soldering the component on the PCB. In a PCB the tracks are
quite closely spaced and probability of damaging them is more with inexperienced persons. This
demands him to have complete concentration. The risk of damaging the track is most while
soldering them off. Use of holder is certainly more advantageous for the soldering the ICs on the
PCB. This way we need not decoder the ICs to replace in case of failure.
TROUBLESHOOTING MANUAL
1. Output voltage of LM7805 is not 5V
Test the continuity throughout the wires, as shown in the circuit diagram. Replace appropriate component, if needed.
2. DC motor is not rotating
Check the current flowing through the motor. If it reaches above 750mA, then the motor is short, Replace it.
In case of jamming, try to grease the bearing and shaft.
3. The display rotates, but not displaying garbage values.
Check the red strip (Interrupt) is in proper position or not. If not, adjust it.
4. Some or all LEDs not glowing.
Check the relimate connector that connects the LED module to the microcontroller.
Otherwise, check the continuity through each wire. If the connections are ok, then replace the particular LED.
BILL OF MATERIALS :
SR.NO COMPONENT NAME REFRENCE
NUMBER
QUANTITY RATE PER UNIT
AMOUNT
1. MICROCONTROLLER AT89V52RD2 1 55.00 55.00
2. REGULATOR IC LM7805 1 7.00 7.00
3. LED RED 8 1.00 8.00
4. DC MOTOR 2400 RPM 1 45.00 45.00
5. TAPE RECORDER FLYWHEEL
1 40.00 40.00
6. COPPERCLADE PCB 2 35.00 70.00
7. CAPACITOR 10µF,16V
33pF
2
2
1.50
1.50
3
3
8. CRYSTAL OSSCILLATOR
4.0952MHZ 1 7.00 7.00
9. IC BASE 40 PIN 1 1.00 1.00
10. SOLDERING WIRE 15METER 1 10.00 150.00
11. RELIMATE CONNECTOR
8 PIN
2 PIN
3
1
6.00
3.00
18.00
3.00
12. RESISTERS 10KΩ
1KΩ
220Ω
310KΩ
1
1
1
1
1.00
1.00
1.00
1.00
4.00
13. SENSOR IC MOC 7811 1 20.00 20.00
14. TRANSISTOR 2N3904 1 8.00 8.00
15. BATTERY +9V 1 38.00 38.00
16. ADAPTER +12V 1 45.00 45.00
17. ADAPTER SOCKET 3 PIN 1 15.00 15.00
TOTAL: 546/-
ADVANTAGES:
• It uses only 8 LED’s for display so hardware requirement is less.
• Maintenance and repairing is so easy.
• All the synchronizing can be implemented through software.
• Cost is very low.
• Because of its small size it take small space.
APPLICATION:
These displays are used at following places:
1. Large public Displays
2. Information Systems
3. For advertisement
4. Railway stations
5. Bus stands
6. In multiplex
RESULT AND CONCLUSION:
This project includes testing of three modules as stated below
1. Interrupter module testing
2. DC Motor RPM testing
3. Power supply module testing
INTERRUPTER MODULE TESTING
This Interrupter module testing is required for detecting exact position of wheel on which
whole circuit assembly is mounted.
Supply voltage given to Pin. No. 1(Collector) and Pin.No.3 (Anode) of MOC7811=5.5V
Output voltage obtained at Pin.No.1 of MOC 7811 without interrupt=5.21v
Output voltage obtained at Pin.No.1 of MOC7811 with interrupt=0.08V
DC MOTOR RPM TESTING
DC Motor used in this project is 12 V dc motor which is tested by using digital contact-
less tachometer. Arrangement was made so that the sensing circuit gives high to low pulse for
each completion of revolution. By measuring the time difference between two successive pulses
RPS can be calculated which further provide RPM value, as shown below:
Power supply given to DC Motor = 12V.
Time interval between two successive pulses as seen on CRO = 30.4ms
RPS = 1 / (30.4ms)
=32.89
RPS = 33
RPM= 33x60
POWER SUPPLY MODULE TESTING
Power supply module was designed to provide 5V DC power supply necessary to drive both
motor and circuit. AC input is given from 9V 750mA transformer. Results are as follows.
Input voltage, Vs=9V AC
Output voltage observed, Vo = 4.92V DC
RPM = 1975 /min
FUTURE SCOPE:
• Propeller Clock.
• Message Flasher.
• Bike wheel LED display.
• Commercial product Children toy spinner.
REFRENCES:
The reference support that the circuit diagram and other related information taken from
website:
1. http://www.luberth.com/analog.htm
2.
http://www.jogy.ch/files/Circuit_Cellar_Design_Contest_H3210/Propeller_Display.pdf
3. http://www.8051projects.net/comment-n153.html
4. http://www.circuitlake.com/propeller-128-light-contoller.html
5. http://www.gadgetgangster.com/news/45-designer-news/290-led-matrix-displays-
with- the-prop.html
Various books have been referred for the designing of the circuit and to understand the
circuit in depth:
The books referred are:
1. MICROCONTROLLER THEORY AND APPLICATION
----- By M.A.MAZZIDI.
Second Edition, Pearson
Prentice Hall.
2. BASIC ELECTRONICS -----By B. Basavaraj &
H.S.Shivashankar, second
edition, Vikas Publication.