EPISODE – 3
CE 3.1 In this
career episode I’m mentioning the project which I completed during my Bachelors
of Technology in Electronics and communication Engineering stream. This is the
final year project in fourth year second semester. The project span was of 3
months that is from January 2011 to March 2011. This project was an industrial
project and completed by the great support from the recognized industry DLRL also
known as Defence Electronics Research Laboratory, Hyderabad, India. Defence
Electronics Research Laboratory (DLRL) was recognized in 1961 under the government
organization Defence Research and Development Organization. Defence Electronics
Research Laboratory works in regards to designing and manufacturing the
Electronic systems which are used for warfare and develops these devices for
Telecommunication and RADAR signal frequency levels. DLRL has many well-known
scientists and engineers as manpower. The Industry is supported by highly
engineered hardware and software designing and development services. I was a student
member selected from my college for the project called “Infra-Red Light Dimmer”.
3.2 The project was part of studies and was accomplished under the supervision
of an internal guide Mr P. Ramesh, Assistant Professor, Department of
Electronics and Communication, JNTU. The purpose of the project is to design
and develop a system called “IR light Dimmer”.
device we develop controls light using an IR remote device. Nowadays most of
the appliances are controlled using remote control device, people needs remote
control for smooth operation and for better convenience and efficiency. A remote
control has many operations on the device such as ON/OFF and many other for the
ease of use. Light dimmer adjusts the voltage of the lamp. Previous Light
dimmers consists of resistors and variable transformers. Those methods are big,
expensive and had poor efficiency. They were hard to control from remote location.
project was undertaken to utilize the opportunity to integrate theoretical
skills into practical learning using subject information of Analog communication,
Control Systems and Embedded Systems. Saving energy is very important but many
electronic devices consumes much energy. My aim in this was that it would be
better if can save energy by dimming the light of the remote control lamp. As a
part of the project team, I demonstrated my skills of critical thinking,
problem solving ability and professional experience of engineering practices.
Following are the characteristics and efforts
in project planning that are required for a team to accomplish this engineering
project at the Bachelor of Electronics Level:
of Microprocessor and Microcontrollers
program language for ZILOG Z8Encore and PIC16F628
configurations and specification
of performance and Structural reporting.
of Print circuit boards.
on the software Protel99.
CE 3.3 The project consists of several process and
procedures for the fulfilment and all the team members were assigned specific
roles and responsibilities upon discussion with the supervisor.
The roles and
responsibilities handled or taken care by me are:
Analysis of the project and
creation of project flowchart
Information gathering on the IR
Dimmers available in Market and
Designing of the project layout
Print Circuit Board virtual
Software code Design
Simulator Software for testing
Maintaining Project Thesis
Project Presentation and
professional people who brings technical skill and knowledge from various
sources to provide solution to difficult problems. The same was demonstrated by
me by utilizing my subject knowledge and expertise throughout the project. When
I received the project paper I discussed with my guide. I had noted all the
possible methods to complete the project within specified time. I gathered all
articles and journals to collect information on the IR and dimmer devices available
and their performance. I created a list to plan the project. Following list
shows the steps taken towards the accomplishment of task:
Stated the purpose of the
Looked at the positive and
negative aspects of the project
Mentioned the Negatives.
Identify the causes to eliminate it.
Mentioned Hardware and software
If Specifications didn’t match
checked for the alternative solutions
Selection of best alternatives
project was separated into sections to eliminate complexity of tasks and to analyze
every region carefully. The different sections of this project contains
knowledge improvement, designing, implementation, testing, Programming, records
and documentation and presentation.
Personal Workplace Activity:
CE 3.4 This
Final semester project provided me the exposure to the field of electronics and
communication. I was able to apply all the subject knowledge which I gained in
my studies like, Microprocessor and Interfacing, Electronic Devices and Circuits,
Verilog design and digital circuits to successfully fulfil the goal of the
This final year
project seriously exposed me to the world of Electronics and computing. I was
able to implement all the conceptual knowledge gained from subjects like VLSI design,
Microprocessors and interfacing, Electronics Devices and Circuits and Pulse and
Digital circuits in order to successfully accomplish the objectives of this
project. This project endorsed me to develop my practical knowledge and skills
in the field of Electronics and communication engineering.
Figure 1: Light Dimmer Circuit.
CE 3.5 I initiated
the project with a basic block diagram of things essential for implementation.
The structure was crafted in a way that the project which is divided into segments
can be easily understand and completely manageable. So the project consists of
several streams such as Microcontroller, Interrupt Controller, and Timer and
Power unit. With the help of the guide proper modules were applied in this
CE 3.6 Since the
role and responsibility given to me was to develop basic designs for all the
parts mentioned. I started with the Microcontroller and Interrupt controller. I
selected PIC16F628X microcontroller which is Low voltage program design, Flash based
8-bit CMOS, and less speed Clock type. With these features it should provide
proper space for the development of software.
Below is the PIN
diagram of the microcontroller:
2: PIC16F628 Chip
Controllers basically used is PIC16F628X with a 433MHZ transmitter, it has 2
buttons to increase and decrease set point, start button and Stop. By means of
USART module the 8-bit data is transmitted and at the receiver side it is
matched. We implemented this matching methodology to make the transfer of data
unique from other signals.
CE 3.7 I had decided to design and develop remote
control which from my experience was easy to build, that can detect IR sensor on
the main board.
Reception of IR waves
and their computation:
emits an Infra-Red ray which is received by a receiver and remote control
operates the functionality of the ray. When a button is operated the LED emit
pulses of Infra-Red radiation that are exclusive only for the operated button
because these pulses contains unique code that are specially coded for it and
are expressed in binary digits. For example, when a power button is operated, a
sequence of pulses will be emitted and can be seen in measuring device. At the
receiver end it is converted into a code which contains information, such as 010
110. Pressing buttons on the remote will generate these codes but in different
sequence as every button is allocated a different code. As we know there are IR
rays all around us, from sun, street lights, etc. but remote controls detect
devices which have specific frequency and wavelength. There are possibilities
that a noise occurrence can disturb the signal but that chances are less.
Carrier Frequency of Infrared Signals
Infra-red signals have carrier frequency which is usually around 36 kHz. The
control codes are sent in serial format modulated to that36 kHz carrier
frequency (usually by turning the carrier on and off).There are many different
coding systems in use, and generally different manufacturers use different
codes and different data rates for transmission.”IR” stands for
infrared. Infrared light is invisible since its frequency is below that of
visible red. Otherwise, it is like any other light source, operating under the
same laws of physics. In most cases, the IR signals are produced by an LED
source. TV remotes send commands only one way, in a low-speed burst for
distances of up to 30 feet. They use directed IR with LEDs that have a moderate
cone angle to improve ease-of-use characteristics. The IR signal sent out by
those devices is generally modulated to around 38 kHz carrier using amplitude
shift keying (carrier on or off). The data rate send is generally in range of
100-2000 bps. Please note that there are some IR systems which use other
frequencies and other modulation systems. IR transmit and receive systems are
inexpensive and are generally reliable.
3.8 I went on to design Interrupt Controller, Timer Module which was the hardest
& interesting part I ever encountered in this project. The 64K Series device supports up to 24
interrupts. These interrupts consist of 12 internal and 12 general-purpose I/O
pins. The interrupts have 3 levels of programmable interrupt priority.
Controller Block Diagram
The timers with the limitation
of four 16 bit reloadable timers can be implemented for counting/timing events
or for motor control. These
timers offer a 16-bit programmable reload counter that operate in single shot, Uninterrupted,
Gated, Capture, Compare, Capture and Compare, and Pulse Wave Modulation modes.
Only 3 timers (Timers 0-2) are accessible in the 44-pin packages.
4: Timer Block
I had attended
regular group meetings with my team members and my supervisor ” and my respected Professor/Head of the Department ”
to get some suggestions from them. This approach helped me in correcting the
various minor faults in the module design and coding at different phases of the
project straightaway and thus avoided a possible mishap during the later stages
that could result in waste of time and efforts. I also referred to the most
powerful tool ‘The Internet’ to get more ideas on how things work. I had
finally written a code for this Object sensing and Speed control unit, which
was first verified by my fellow team members and my supervisor. Then I
implemented and tested this code in my project and it was functioned perfectly.
I have implemented short range IR sensors for demonstration purposes.