1 In thiscareer episode I’m mentioning the project which I completed during my Bachelorsof Technology in Electronics and communication Engineering stream. This is thefinal year project in fourth year second semester. The project span was of 3months that is from January 2011 to March 2011. This project was an industrialproject and completed by the great support from the recognized industry DLRL alsoknown as Defence Electronics Research Laboratory, Hyderabad, India. DefenceElectronics Research Laboratory (DLRL) was recognized in 1961 under the governmentorganization Defence Research and Development Organization.
Defence ElectronicsResearch Laboratory works in regards to designing and manufacturing theElectronic systems which are used for warfare and develops these devices forTelecommunication and RADAR signal frequency levels. DLRL has many well-knownscientists and engineers as manpower. The Industry is supported by highlyengineered hardware and software designing and development services.
I was a studentmember selected from my college for the project called “Infra-Red Light Dimmer”. Background:CE3.2 The project was part of studies and was accomplished under the supervisionof an internal guide Mr P. Ramesh, Assistant Professor, Department ofElectronics and Communication, JNTU. The purpose of the project is to designand develop a system called “IR light Dimmer”.Thedevice we develop controls light using an IR remote device. Nowadays most ofthe appliances are controlled using remote control device, people needs remotecontrol for smooth operation and for better convenience and efficiency. A remotecontrol has many operations on the device such as ON/OFF and many other for theease of use.
Light dimmer adjusts the voltage of the lamp. Previous Lightdimmers consists of resistors and variable transformers. Those methods are big,expensive and had poor efficiency. They were hard to control from remote location.Theproject was undertaken to utilize the opportunity to integrate theoreticalskills into practical learning using subject information of Analog communication,Control Systems and Embedded Systems. Saving energy is very important but manyelectronic devices consumes much energy. My aim in this was that it would bebetter if can save energy by dimming the light of the remote control lamp. As apart 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 effortsin project planning that are required for a team to accomplish this engineeringproject at the Bachelor of Electronics Level: Understanding of Microprocessor and Microcontrollers Embedded program language for ZILOG Z8Encore and PIC16F628 Hardware configurations and specification Measurement of performance and Structural reporting. Understanding of Print circuit boards. Knowledge on the software Protel99. CE 3.3 The project consists of several process andprocedures for the fulfilment and all the team members were assigned specificroles and responsibilities upon discussion with the supervisor.
The roles andresponsibilities handled or taken care by me are: · Analysis of the project andcreation of project flowchart· Information gathering on the IRtechnologies· Dimmers available in Market andtheir specifications· Designing of the project layout· Hardware requirements· Print Circuit Board virtualdesign· Software code Design· Simulator Software for testingthe device· Maintaining Project Thesis · Project Presentation andDemonstrationEngineers areprofessional people who brings technical skill and knowledge from varioussources to provide solution to difficult problems. The same was demonstrated byme by utilizing my subject knowledge and expertise throughout the project. WhenI received the project paper I discussed with my guide. I had noted all thepossible methods to complete the project within specified time. I gathered allarticles and journals to collect information on the IR and dimmer devices availableand their performance. I created a list to plan the project. Following listshows the steps taken towards the accomplishment of task:· Stated the purpose of theproject.· Looked at the positive andnegative aspects of the project· Mentioned the Negatives.
Identify the causes to eliminate it.· Mentioned Hardware and softwarespecifications required· If Specifications didn’t matchchecked for the alternative solutions· Selection of best alternativesThe overallproject was separated into sections to eliminate complexity of tasks and to analyzeevery region carefully. The different sections of this project containsknowledge improvement, designing, implementation, testing, Programming, recordsand documentation and presentation.
OrganizationalStructure: Personal Workplace Activity:CE 3.4 ThisFinal semester project provided me the exposure to the field of electronics andcommunication. I was able to apply all the subject knowledge which I gained inmy studies like, Microprocessor and Interfacing, Electronic Devices and Circuits,Verilog design and digital circuits to successfully fulfil the goal of theproject. This final yearproject seriously exposed me to the world of Electronics and computing. I wasable to implement all the conceptual knowledge gained from subjects like VLSI design,Microprocessors and interfacing, Electronics Devices and Circuits and Pulse andDigital circuits in order to successfully accomplish the objectives of thisproject. This project endorsed me to develop my practical knowledge and skillsin the field of Electronics and communication engineering. Figure 1: Light Dimmer Circuit. CE 3.
5 I initiatedthe 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 segmentscan be easily understand and completely manageable. So the project consists ofseveral streams such as Microcontroller, Interrupt Controller, and Timer andPower unit. With the help of the guide proper modules were applied in thisproject.
CE 3.6 Since therole and responsibility given to me was to develop basic designs for all theparts mentioned. I started with the Microcontroller and Interrupt controller. Iselected PIC16F628X microcontroller which is Low voltage program design, Flash based8-bit CMOS, and less speed Clock type. With these features it should provideproper space for the development of software.Below is the PINdiagram of the microcontroller: Figure2: PIC16F628 ChipRemoteControllers basically used is PIC16F628X with a 433MHZ transmitter, it has 2buttons to increase and decrease set point, start button and Stop. By means ofUSART module the 8-bit data is transmitted and at the receiver side it ismatched. We implemented this matching methodology to make the transfer of dataunique from other signals.
CE 3.7 I had decided to design and develop remotecontrol which from my experience was easy to build, that can detect IR sensor onthe main board.Reception of IR wavesand their computation:The LEDemits an Infra-Red ray which is received by a receiver and remote controloperates the functionality of the ray. When a button is operated the LED emitpulses of Infra-Red radiation that are exclusive only for the operated buttonbecause these pulses contains unique code that are specially coded for it andare expressed in binary digits.
For example, when a power button is operated, asequence of pulses will be emitted and can be seen in measuring device. At thereceiver end it is converted into a code which contains information, such as 010110. Pressing buttons on the remote will generate these codes but in differentsequence as every button is allocated a different code. As we know there are IRrays all around us, from sun, street lights, etc. but remote controls detectdevices which have specific frequency and wavelength. There are possibilitiesthat a noise occurrence can disturb the signal but that chances are less. Carrier Frequency of Infrared SignalsTheInfra-red signals have carrier frequency which is usually around 36 kHz.
Thecarrier frequency of such infra-red signals is typically in the order of around36 kHz. The control codes are sent in serial format modulated to that36 kHzcarrier frequency (usually by turning the carrier on and off).There are manydifferent coding systems in use, and generally different manufacturers usedifferent codes and different data rates for transmission.”IR” standsfor infrared. Infrared light is invisible since its frequency is below that ofvisible red. Otherwise, it is like any other light source, operating under thesame laws of physics. In most cases, the IR signals are produced by an LEDsource.
TV remotes send commands only one way, in a low-speed burst fordistances of up to 30 feet. They use directed IR with LEDs that have a moderatecone angle to improve ease-of-use characteristics. The IR signal sent out bythose devices is generally modulated to around 38 kHz carrier using amplitudeshift keying (carrier on or off). The data rate send is generally in range of100-2000 bps. Please note that there are some IR systems which use otherfrequencies and other modulation systems.
IR transmit and receive systems areinexpensive and are generally reliable.