Design & Implementation of Color Sensor

Presentation on Design & Implementation of Color Sensor.

Introduction

Light is a physical phenomenon.When the components of light are absorbed or transmitted in different proportions by an object, color occurs. The color of an object is apparent only when light strikes the object. For color to be perceived, the viewer must have blue, green, and red receptors. Depending upon its chemical make-up, matter has the ability to absorb, reflect or transmit visible light.

When all the components of visible light are absorbed by matter, the object is said to be black.On the other hand, if all the components of visible light are reflected or transmitted by the object, the object is considered white or clear. The visible light spectrum is a small part of the electro-magnetic spectrum. The visible spectrum has a wavelength range of about 380 to 740 nm. Human eye can perceived only the visible light.

Wavelength & frequency interval of different colors

Color Name	Wavelength Interval nm	Frequency Interval THz
Violet	380-450	668-789
Blue	450-495	606-668
Green	495-570	526-606
Yellow	570-590	508-526
Orange	590-620	484-508
Red	620-750	400-484

Objectives

The main objective of our project is to detect the color of an object. Our target is to detect ten colors.The target colors are Black, Green, Red, Blue, Yellow, Magenta, Yellow-lemon,Pink,
Gray, White.
To relate color system wherein color purity and mixings is identified perfectly and is independent of human observations or subjective judgments.
Possible Outcome

To detect the color of an object with high precision even under varying environment conditions, such as fluctuations in the ambient temperature or variations of incidence light on the object to be measured.

Experimental Design

A color sensor includes a light receiving element for receiving the light from an object(target) illuminated by the lights from the light emitting sources and a circuit arrangement for producing output signals representing the color of the object.

Experimental Design


Op-amp

The op-amp is basically a differential amplifier having a large voltage gain, very high input impedance and low output impedance. Most of the time operational amplifiers are used to compare voltages of unequal magnitudes. They are called ``operational'' amplifiers, because they can be used to perform arithmetic operations (addition, subtraction, multiplication) with signals.

Op-amp Circuit Notation


V ₊ : non-inverting input
V- : inverting input
V_out : output
Vs₊: positive power supply
Vs-: negative power supply
Pin Connection of LM741


Analog-to-digital converter (ADC)

An analog-to-digital converter (A/D) takes an analog voltage or current and after a certain amount of time it produces a digital output code that represents the analog input.

Simply, an analog-to-digital converter is a device which converts continuous signals to discrete digital numbers.

General Block Diagram (ADC)



Pin diagram & free running connection


Pin diagram of ADC0804


Free running connection

Microcontroller

Microcontroller is a programmable integrated circuit which contains Processor, memory and input/output functions in a single chip. It is a microprocessor emphasizing high integration. In contrast to a general-purpose microprocessor, the microcontroller integrates additional elements such as read write memory for data storage, read-only memory for program storage, EEPROM for permanent data storage, peripheral devices, and input/output interfaces.

Pin diagram (PIC16F84A)


Pin function


Circuit Diagram




Program

TRISA = 0
TRISB = 255
Dim a As Byte
PORTA = 0
WaitMs 10
main:
PORTA = 0
a = PORTB
If a < 11 Then PORTA = 1 '//Black
If a > 6 Then
If a < 27 Then PORTA = 2 '//Blue
Endif
If a > 26 Then
If a < 31 Then PORTA = 3 '//green
Endif
If a > 39 Then
If a < 44 Then PORTA = 4 ''// Pink
Endif
If a > 44 Then
If a < 50 Then PORTA = 5 '//Red
Endif
If a > 49 Then
If a < 57 Then PORTA = 6 '//Megenta
Endif
If a > 56 Then
If a < 63 Then PORTA = 7 '// White
Endif
If a > 64 Then
If a < 73 Then PORTA = 8 '//Yellow
Endif
If a > 89 Then
If a < 93 Then PORTA = 9 '//Gray
Endif
If a > 92 Then
If a < 96 Then PORTA = 10 '//Yel+lem
WaitMs 200
Goto main
Result

Our project is designed for detection of ten colors. But we have detected eight colors successfully. The detected eight colors are red, green, yellow, yellow-lemon, pink, gray, black & white.

Error

We can’t detect two colors. The colors are blue & magenta. This two colors are overlapped with green & red.
Limitation

1. The major limitation of our project is that it can’t detect the object which contains number of colors.
2. One limitation of this project is that it can’t display the color name. But it is possible to display the color name with the help of LCD display by proper programming.
3. Our blue sensor can’t work properly. So we can’t detect the blue color as well as other color.
4. We can’t filter the color perfectly.

Future study & improvement

1. To display the detected color name.
2. To increase the number of detected color.
3. To detect number of colors even exist as a narrow strip within the object.
4. Sort objects by color

Reference

1. “Digital Systems Principles and Applications” By, Ronald J. Tocci, Neal S. Widmer & Gregory L. Moss
2. “Digital Logic and Computer Design” By, M. Morris Mano
3. “Operational Amplifiers and Linear Integrated Circuits” , Sixth edition By, Robert F. Coughlin and Frederick F. Driscoll

Submitted By Anup Kumar Das and Prashanta Kumer Sarker

DESIGN AND IMPLEMENTATION OF QUEUING DISPLAY AND SOUND SYSTEM

Presentation on DESIGN AND IMPLEMENTATION OF QUEUING DISPLAY AND SOUND SYSTEM

INTRODUCTION

The queuing display system is a system that displays the servicing number, counter number which is usually used in the bank, payment counter and other service counters.

OBJECTIVES

1. To design and implementation of 8051-Based Queuing display system.
2. To design and implementation of corresponding sound system.

WORKING PRINCIPAL

DISPLAY SYSTEM

SOUND SYSTEM

IMPLEMENTATION (DISPLAY PART)

Microcontroller
Port 3.0 is connected to pushbutton switch.
Port 3.1-3.5 is connected to seven segment’s common pin
Port pins 1.0 - 1.3 are connected to LED’s.
Pins 1.4 - 1.7 are connected to pushbutton switch.
Pins 2.1 - 2.7 are connected to seven segment displays.
IMPLEMENTATION (SOUND PART)
Counter system

Token system

RESULTS
Display system:

Sound system:

FUTURE PLAN

1. The sound system can be digitalized by using computer software interfacing with the circuit switch.
2. Microcontroller can be used for randomly sound selection.

CONCLUSION

1. Economic operation is important for any equipment.
2. The components using in this project are available.

REFERENCES

1. The 8051 Microcontroller architecture programming and applications- by Kenneth J. Ayala
2. http://www.8051projects.net/out.php?link= http://img391.imageshack.us/my.php?image=schajc6.jpg
3. http://www.8051projects.net/plugins/forum/forumviewtopic.php?1201.20#post_1410

Submitted by Towhidul Ahad

DIGITAL DAY AND CYCLE COUNTER BY MEANS OF MICROCONTROLLER

Presentation on DIGITAL DAY AND CYCLE COUNTER BY MEANS OF MICROCONTROLLER

Introduction

In Modern era all analog systems are replaced with digital system as digital system are giving better accuracy and results than Analog. In digital system Microcontroller is very common and yet essential element by which conditional problems can be solved easily. My project is to make a digital day and cycle counter by means of microcontroller for the department of EEE.

Objectives

1. The objectives of this project is given below-
2. To count different days and displaying them by means of microcontroller automatically.
3. To count different cycles and displaying them in seven-segment display by means of microcontroller automatically.
4. To pause the arrangement in different situations.

Block Diagram for circuit

Description of the Process

Here when the circuit is switched on then the counter will start counting the day. The days are A,B, C , D and E. Each day will exist for 24 hour. After 5 day has counted than for 2 days off the last day i.e Day E (Led) will exist 72 hour. And thus a cycle will complete and the display will show the output. The process will continue for 13 cycle. After completing 13 cycle the whole process will be reset and again start to count the cycle. Here is a option to pause the cycle at any time if any batch class is off.

Overall Circuit Diagram

Circuit Description

First when the circuit is switched on the day counter will start counting the day. The microcontroller is so programmed that the “day display” unit will display the day for 24 hour for A, B , C , D and 72 hour for day E. The counter 1, 2 ,3, and 4 will count the cycle. The microcontroller programming is set that it will allow the counter to count for 13 cycle. After 13 cycle the microcontroller will reset the counters.

Counters

1. To count different days and cycles two types of counters are used-
2. 4017 decade counter to count days
3. 4026 counter and 7-segment display driver to count cycles

Microcontroller

1. The microcontroller used in this project is PIC16F84A.
2. Here the microcontroller will control the counters according to programming.
3. Here the output pins are B0, B1, B2, B3, B4,B5, B6 and B7. Each pin is connected to counter and corresponding reset point.

Recommendation

1. Now a day’s LCD displays are most widely used in displaying. So LCD display can be used instead of 7-segment display.
2. Advanced microcontroller with built in counter can be used instead of external counter.

Conclusion

1. Multipurpose of any equipment is most desirable criteria in modern technology. So at the time of designing of this project, idea was gathered in such way so that it can give several number of information.
2. Now a day’s economic operation is another criterion for any equipment. Since materials required implementing this project is available in market so implementation of this project is trouble-free and cost effective.

Submitted by Md. Tawhidul Alam

DESIGN AND FABRICATION OF FARE METER USING MICROCONTROLLER

Presentation on DESIGN AND FABRICATION OF FARE METER USING MICROCONTROLLER

Project Introduction:

In Modern era all analog systems are replaced with digital system as digital system are giving better accuracy and results than Analog. In digital system Microcontroller is very common and yet essential element by which conditional problems can be solved easily. Our project is to make a digital fare meter for taxicab with microcontroller and digital display.

Objective/Task of the Project:

1. To design a circuit with microcontroller which could measure the mechanical rotation of Wheels and hence distances.
2. To write the program by which the fare of the cab can be calculated according to measured distances with local taxi cab fare rule and rate.
3. Finally display the measured output in a Digital display.

Outline of the project

1. Block diagram of the fare meter.
2. Wheel rotation of the measurement.
3. Measurement unit.
4. Programming of the microcontroller.
5. The display unit.
6. The main circuit.
7. Experimental set up in lab.
8. Advantage with the existing one.
9. Future expansion.

Block diagram of the Fare meter:

Wheel Rotation Measurement:

1. There will be a mechanical setup connected to the measurement unit so that it could count the no of rotations of wheel.
2. The wheel size or diameter is also need to be measured for distance measurement.

Measurement Unit:

1. This is the main part of our project.
2. This unit consist a microcontroller and the counter.
3. Counter will send a pulse for each rotation to the microcontroller where microcontroller can receive maximum 15 pulses in a second.
4. The microcontroller than measure the distance from receiving the pulse from counter which is preprogrammed in it.
5. After fare calculation the microcontroller send the output to the display unit.

Programming of Microcontroller:

1. The programming play a vital role here as measuring distance and calculating fare under subsequent condition is determined by programming.
2. The Programming is done in the with the help of software MP LAB,IDE Version 7 and the programmed is loaded into the microcontroller with the programmed loader and hence show output to the display unit.

The Display Unit:

1. The display unit consist a LCD display panel.
2. Here we used a LCD display unit which not only display the fare but also display the distance passed. This is done because the display unit is connected with counter also beside the microcontroller.

The main circuit:

Experimental set up in lab

Advantage over the existing one

1. Low cost compare with the conventional fare meter.
2. High reliability.
3. Less complexity.
4. Can be effectively used with respect to our country.

Future expansion

1. As the device is low-cost and highly effective, it can be employed to taxi and auto-rickshaw fare measurement if we get to manage any engineering production company to produce the device in large scale.
2. Submitted by Md. Saidul Islam and Md. Shahidul Amin

SPEED CONTROL OF A DC MOTOR BY USING PWM TECHNIQUE.

Presentation on SPEED CONTROL OF A DC MOTOR BY USING PWM TECHNIQUE

OBJECTIVE:

1. Design and construction of speed control system of a dc motor.
2. To use voltage control method to control the speed of the dc motor.
3. Implementation of our project by an electronic circuit.
4. To use 8-bit data from computer through parallel cable to the DAC, then to op-amp, PWM generator and to the MOSFET and to the motor, to control the speed of the dc motor.

IMPORTANCE:

There are various types of motor drive working all over the world. These motors are used to drive the various types of loads. With respect to the loads these motors requires various types of speed. So, there is a great need of many speed controlling devices.

DC series motor:

The series motor provides high starting torque and is able to move very large shaft loads when it is first energized.

MOTOR CHARACTERISTICS:

1. Torque.
2. Power.
3. Speed.
4. Torque vs Speed Curves.
5. Power Curves.

Parallel port:

A parallel port is a type of interface found on computers (personal and otherwise) for connecting various peripherals. It is also known as a printer port . The Parallel Port is the most commonly used port for interfacing home made projects. This port will allow the input of up to 9 bits or the output of 12 bits at any one given time, thus requiring minimal external circuitry to implement many simpler tasks. The port is composed of 4 control lines, 5 status lines and 8 data lines. It's found commonly on the back of your PC as a D-Type 25 Pin female connector. There may also be a D-Type 25 pin male connector. This will be a serial RS-232 port and thus, is a totally incompatible port.

Parallel port:

Interfacing:

Computer interfacing: the art of connecting computers and peripherals. In a lot of circumstances, it looks more like magic than art. It is not uncommon that you end up removing all unnecessary hardware from your computer to get that communication device to work. Despite all plug-and-play internal hardware solutions for the PC, connecting a number of external devices still requires some amount of technical knowledge and experience.

PWM Technique:

1. In controlling direct current motors, it is possible to use resistor, autotransformer, transistor etc. to carry out linear current control. The above items are used for dc motor control have very large power consumptions.
2. At present there are two kinds of controlling devices most often used.
3. Pulse width modulation PWM uses a fixed frequency to do opening and closing action , and adds dc power to the motor to control the on/off time of the switch and also control the average voltage. This is called duty cycle control method.
4. Pulse frequency modulation (PFM) ensures the on/off time of the power source and motors are same and that the on/off frequency influences the average amount of voltage to change the motor’s speed.

BLOCK DIAGRAM:

Circuit Diagram:

Limitation:

The main limitation involved with our motor controller is the Electromagnetic interference (EMI). We know the switching or commutation of any switch generates voltage and current transients that are characterized by a whole spectrum of frequencies, ranging from the fundamental power circuit frequency up into the radio frequency band . This EMI creates problem for digital tachometer to show accurate speed reading of the motor. We also observed that at slow speed heat sink heated up quickly. This is because at slow speed i.e. when pulse width of the gate signal of the MOSFET decreases factor (ratio of the a.c components to the average value) also increases and causes the heat sink to heat up quickly. Fluctuations of supply voltage of our machine lab also create problems to control the speed of motor exactly.

Conclusion

A project can open the door of knowledge for a particular topic. It introduces a student to work in practical field. We got such kind of a project “Speed control of a DC motor with the aid of computer’s parallel port” which introduced us with the controlling of a DC motor in a programmable manner as well as visual basic programming language. We saw that there is a difference between theoretical design and practical implementation. This is due to the inherent properties of the circuit equipments. Finally, we can say that this practical work will help us in our working field.

Submitted By MD. SOHAG RANA and MD. RAKIBUL ISLAM

DESIGN, IMPLEMENTATION AND PERFORMANCE ANALYSIS OF AN ULTRASONIC RANGE METER

 

Presentation on DESIGN, IMPLEMENTATION AND PERFORMANCE ANALYSIS OF AN ULTRASONIC RANGE METER

THEORY OF OPERATION

The basic principal of the range meter is based on the simple concepts of SONAR. First, an ultrasonic pulse is transmitted by a transducer. This pulse then reflects off an object and is received by another transducer. Using the known speed of sound and the time between the transmitted pulse and the received pulse, one can simply calculate the distance traveled by the pulse.

Distance= (sound velocity * time interval)/2

BLOCK DIAGRAM


TRANSMITTER CIRCUIT

RECEIVER CIRCUIT

HOLDING CIRCUIT

INTERFACING CIRCUIT OF LCD WITH ATmega32

APPLICATIONS

1. Auto focusing cameras
2. In Automatic braking Cars
3. Motion detection systems
4. Robotics guidance systems
5. In case of black out
6. Object ranging

Item	Specification
Range	17cm-10m
Error rate	+ 3cm
Transducer frequency	40KHz
Internal oscillator frequency	8 MHz
Input voltage	6.6v dc

PERFORMANCE

We could measure about 3.5-m distance. The 10-m distance seems to be able to be measured if the following conditions are followed-

1. The object be perpendicular to the range meter.
2. The surface of the object be flat.

COST ANALYSIS

1. This project costs 1050Tk. But this can be reduced to some extent if we go mass production.
2. If more precise instruments can be used the cost will be reduced to some extent with respect to the maximum distance measured.
3. Though the market price of a range meter ranging about 10m is 2500Tk but If we could successfully implement our design of this device & go to mass production then we could definitely give it at a cheaper rate.

LIMITATIONS

1. It provides less accuracy in an open environment.
2. The velocity of sound depends on air temperature. It increases by 0.6 m/s for an increase in temperature by 1 degree Celsius.
3. The transducers should be operated exactly at 40 KHz to obtain the best result.
4. The range meter can not measure below 17 cm.

FURTHER DEVELOPMENT

In order to use this range meter effectively, followings are advised-

1. To measure long distances, different transducers can be used.
2. To change the distance range, in the code the capture guard timer count and the pulse count can be modified.
3. Frequency modulation technique can also be used.
4. Further development can also be made to make the device handheld.

CONCLUSION

With respect to the requirements for an ultrasonic range finder the following can be concluded- 

1. The system is able to detect objects within the sensing range.
2. The system can calculate the distance of the obstruction with sufficient accuracy.
3. This device has the capability to interact with other peripheral if used as a secondary device.
4. This can also communicate with PC through its serial port.
5. This offers a low cost and efficient solution for non contact type distance measurements.

Submitted by AFSANUL HAQUE & MUHAMMAD NAZAM US SAKIB EMON

Design and Implementation of Digital Blood Pressure Meter

PRESENTATION ON Design and implementation of Digital Blood Pressure Meter

INTRODUCTION:

This application note describes a Digital Blood Pressure Meter concept which uses an integrated pressure sensor, analog signal-conditioning circuitry and microcontroller hardware/software and a liquid crystal display. The sensing system reads the cuff pressure (CP) and extracts the pulses for analysis and determination of systolic and diastolic pressure. This design uses a 50 kPa integrated pressure sensor (Freescale Semiconductor, Inc .P/N: MPXV5050GP) yielding a pressure range of 0 mm Hg to 300 mm Hg.

OBJECTIVE: We have worked to achieve the following goal:

1. To minimize the cost.
2. To maintain the better performance.
3. Easy measuring system.
4. Display with digital unit.

Circuit Diagram

The cuff pressure is sensed by integrated pressure X-ducer. The output of the sensor is split into two paths for two different purposes. One is used as the cuff Since MPXV5050GP is signal-conditioned by its internal op-amp, pressure while the other is further processed by a circuit. The cuff pressure can be directly interfaced with an analog-to-digital (A/D) converter for digitization. The other path will filter and amplify the raw CP signal to extract an amplified version of the CP oscillations, which are caused by the expansion of the subject’s arm each time pressure in the arm increases during cardiac systole. The output of the sensor consists of two signals; the oscillation signal (≈ 1 Hz) riding on the CP signal ( ≤ 0.04 Hz). Hence, a 2-pole high pass filter is designed to block the CP signal before the amplification of the oscillation signal. If the CP signal is not properly attenuated, the baseline of the oscillation will not be constant and the amplitude of each oscillation will not have the same reference for comparison.

CP Signal at the output of the pressure sensor

Extracted Oscillation Signal at the Output of amplifier

Zoom-in View of a Pulse

Output versus Pressure

Comparison between our blood Pressure meter and Omron digital blood pressure meter

Cost Analysis

Parts name	Quantity	Price(TK)
R0,R1,R2,R3,R4,R5,R6,R7,R8,R9,R10	10	30
C1,C2,C3,C4,C5,C6,C7,C8	8	60
LED	1	1
BUZZER	1	30
Crystal Oscillator	1	10
MPXV5050GP	1	1500
LM324N	1	20
MC78L05ACP	1	25
MC34064	1	20
ATmega16	1	180
LCD Display	1	250
Wire	-	10
Cuff	1	70
Total		2206

METHODOLOGY:

1. Theoretical study and analysis of pressure sensor and microcontroller.
2. Calibrate the sensor in corresponding of pressure.
3. Programming the microcontroller.
4. Showing the systolic and diastolic pressure in LCD display.

Future Improvement
Our Digital Blood Pressure Meter can be further improved by-
-Software programming
-Pressure sensor

CONCLUSION: This circuit design concept may be used to evaluate pressure sensors used in the digital blood pressure meter. This basic circuit may be easily modified to provide suitable output signal level. The software may also be easily modified to provide better analysis of the SBP and DBP of a person and also to calculate the pulse rate.

REFERENCE:
[1] Electronic Principles, by Albert Paul Malvino p.h.d,EE,6^th edition,pp 855-898.
[2] www.lvr.com,The Microcontroller Ideal Book, by Jan Axelson,pp 1-10.
[3] www.atmel.com. ATmega 16,data sheet.
[4] IC Design project, by Stephen kamaichick, first edition.
[5] www.alldatasheet.com. MPXV5050GP,data sheet.
[6] www.alldatasheet.com. LM324N,data sheet.
[7] www.mickrobasic.com
[8] www.alldatasheet.com,16×2 Display,Datasheet.
[9] www.fastavr.com
Submitted by Md. Omor Faruk Sharker and Abdul Halim Khan