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Monday, August 24, 2020
Creative Accounting Free Essays
The term of innovative bookkeeping alludes to choose bookkeeping strategies for the arrangement of fiscal report that give the outcome wanted by the bookkeeping preparers. Particularly when the organizations are under a budgetary trouble, the need of imagination would be extremely evident on the grounds that it may be hard for gatherings, for example, reviewers, with an oversight work, to report that the record preparers are doing anything incorrectly (Deegan, 2010). At the point when the economy is moving into downturn, the most organizations are probably going to control their fiscal summary to be the upward way all together for the great benefit by exaggerating the advantage and downplaying the risk. We will compose a custom article test on Inventive Accounting or on the other hand any comparable subject just for you Request Now b) No, the jobs and duties of evaluators and controllers are essential at improving control. Inspectors perform reviews to assess whether the approaches and procedure are planned and working viably and give suggestions to progress. They likewise help to screen and assess the viability of the associations chance administration forms. They may set up a far reaching evaluation of any wrong doing that may lead the association into money related misfortune. With respect to the job of controllers, they will decide how best to cause firms subject to their ward to create control strategies and systems to meet the presentation targets. Truth be told, evaluators and controllers are a piece of the mainstays of corporate administration. The reviewers and controllers certainly work to anticipate the notice of the downturn and offer notice to the organization. Be that as it may, they couldn't be in position to complete ultimate conclusion and to control each improvement and procedure. Much the same as the HIH protection case, the chiefs despite everything settle on wrong choice, regardless of whether there was the simultaneousness of the statisticians and the evaluators. It doesn't make a difference how productively they assumed their job, it makes a difference how effectively the four columns which are guest of executives, the board, examiners and controllers could be blended with. In other word, this disappointment ought not be the motivation to decrease the jobs of inspectors and controllers. Instructions to refer to Creative Accounting, Papers
Saturday, August 22, 2020
Marketing Communication Strategy - Sales Promotion Assignment
Showcasing Communication Strategy - Sales Promotion - Assignment Example à Direct showcasing is a channel type of publicizing that helps business just as non-benefit associations to legitimately speak with the clients with the assistance of different promoting procedures like online presentation of advertisements, list dispersion, portable informing, limited time letters and so forth. Publicizing is a type of correspondence that assists with convincing the crowd to make some move. The activity is buy the item or administration. A productive and powerful showcasing correspondence blend is basic in any case the organization won't make due in the serious commercial center. Viable showcasing correspondence with clients is fundamental so as to produce benefits and deals. Presently with regards to the undertaking, the two organizations that have been decided to show the utilization of the referenced correspondence blends are KFC and McDonalds. Both KFC, just as McDonald's, gigantically put resources into their correspondence procedure. The report will start by giving a short prologue to the picked organizations as it will assist with relating the subject all the more effectively. The report will likewise feature the 3 significant advertising correspondence blends utilized by them in the commercial center. Aside from that, the report will likewise stress the significance and extent of the referenced correspondence blend. With regards to the undertaking, the accompanying three significant components utilized as the limited time components are notices, deals advancement and open connection. The viability and productivity of promoting correspondence systems of KFC and McDonalds are:- Deals Promotion: - Sales advancement is among the seven components of the limited time blend. Instances of deals advancement incorporate the challenge, markdown coupons, item tests and different complimentary gifts (Gartner and Bellamy, 2009, p.350). Presently with regards to the venture, KFC utilizes deals advancement to an enormous degree. The organization utilizes the accompanying devices so as to additionally improve the deals. It incorporates coupons, premiums and amusement. Each outlet of KFC offers the diverse sort of motivating forces, for example, coupons, the free extra, and the free supper to the clients with the end goal of selling.â Ã
Wednesday, July 22, 2020
The Best of Medium
The Best of Medium I cannot tell a lie: I havenât been up on my book game as much as I should be. Blame the summertime, the new job, or the 5k training program Iâm on. Buying or even borrowing books hassadlybeen one of the last things on my mind, but that doesnât mean I havenât been reading. In fact, I read every day (and not just the captions on celebrity Instagram photos). Lately, Iâve been getting my story fix through my other source of entertainment/wisdom/procrastination: the internet. Namely, Iâve been hooked on Medium. If you havenât heard of it, Medium is a free blog-hosting site that focuses on offering writers and readers a clean, streamlined experience with words. You wonât find awesome blog themes, but you will definitely come across a host of short story collections and essays featuring popular as well as up-and-coming writers from all over. The best part? You, too, can enlighten the world with your thoughts there if you so desire. Maybe one day Iâll catch myself reading yours while in line at Starbucks one morning. Anyway, here are a few of my favorites: Human Parts According to their mission statement, âHuman Parts explores the patchwork of the human condition through experimental and traditional personal writing.â With a mixture of first-person narratives and third person works of creative nonfiction (AKA journals with a dramatic twist), Human Parts really scales the landscape of what might be academically the âhuman condition.â The work displayed here addresses some pretty difficult questions ranging from âwas that thing that happened rape?â to âdid my sociopathic mother really love me, or was she just pretending?â If youâre feeling introspective, give this place a try. Big Funny Blog Donât be fooled by the name of this generic-seeming blog. Jason Wolverton is a whiz at the whole self-deprecating thing (not the be confused with the whole defecating in an outdoor trailer thing he recently wrote about). His stories have the power to both entertain and transport the reader to another time and placeâ"perhaps a nine state road trip? Poets Unlimited âWords for humans. Poems on topics diverse, engaging and authentic.â More than just another site cleverly aiming to tackle the human condition head-on, Poets Unlimited is a regular source of musing for me. It features diverse poets in a range of styles, with almost daily updates. The best part about this site is the fact that, no, not all the poetry is rad. Some of it is actually not that great. But I love it anyway (do you remember when I talked about embracing publication as an accomplishment in itself? Remind yourself.) Matter If youâre like me, sometimes you like to get all super-left-wing with it. Sometimes, you even like to get all super-right-wing, too. Donât get me started on the terrors of censorship! Or the terrors of children watching who knows what on the internet! Oh, excuse me. Back to the topic at hand. Matter is a nonfiction blog featuring pieces on current events and popular culture, as well as politics, work life, as well asâ"relationship advice? Matter does it all. And I freaking love it. So the next time you find yourself in a book rutâ"as I somehow am despite the fact that I write about booksâ"consider opening your browser and taking a real-life peek into someone elseâs thoughts and experiences. Then, feeling empowered, consider contributing yourself. Make the internet a little more scary, will you?
Friday, May 22, 2020
Why You Should Stop Your Valuables From Burglars - 785 Words
When moving into a new home, you want to live somewhere you love and where you feel safe. At Trumark Homes, we can provide you with a home you will love in a wonderful community, but there are still several things you should do to protect your valuables from burglars. Donââ¬â¢t Advertise Big Purchases If you have gotten a new flat-screen television or other large item, do not put the box next to your trash, advertising your new item. Be especially careful about doing this after big gift holidays. Instead, break the boxes down, putting them in your recycling or trash bins. If you have gotten several large items, you may even want to break the boxes down and slowly add the boxes to your trash or recycling, hiding the boxes in the bottom of bins. Boxes sitting next to your trash or easily seen by those walking or driving by advertise that you have a new item or new items. If the person is a thief, the opportunity might be too tempting to pass up. Make Sure to Lock-up Roughly 40 percent of burglaries in the United States are not forced entries. This means the people get in through unlocked windows or doors. Whether you are leaving for only an hour or two or you are going on an extended vacation, make sure all doors and windows are properly secure before you leave your home. It is also important to lock the door leading from your garage to your home. Be Careful What You Post on Social Media Although it might be tempting to brag on social media about your upcoming trip to theShow MoreRelatedPersuasive Essay On Gun Control1742 Words à |à 7 PagesImagine somebody breaking into your home with the intentions of hurting you and your family and trying to take all your valuables that you own in your house, and not having anything to protect your loved ones. Without the protection of a firearm, the intruder could injure or kill all members within the household easily. In the United States, according to the Bill of Rights, a citizen has the right to bear arms, however, recently people have started to believe that guns only incite violence andRead MoreBurglary Theories Essay5164 Words à |à 21 Pageswe can see why criminals offend after weighing the rewards against the punishments. The Petit family found this out the hard way when two burglars invaded their home because they were not happy with the bounty that they received from the last two homes they invaded. Unfortunate ly for them this invasion resulted in the death of a mother and her two daughters. Burglary occurs every 15 seconds in the United States and this tragedy could and can happen to anyone. Introduction How and why do peopleRead MoreThe Sensible Nature of Bilbo and Hobbits1382 Words à |à 6 Pagesmanifestation by Tolkien of the moral high ground of hobbits and their rational and peacekeeping nature, which impresses the men and elves to award their trust and honor to the hobbit. Bilbo as the protagonist of the novel appears sensible partly from Tolkienââ¬â¢s underlying representation of a twentieth century English gentlemen. When Bilbo first arrives at the Gate with the Elvenking and Bard, his first speaking point is business. Tolkien describes Bilboââ¬â¢s speech as a ââ¬Å"business mannerâ⬠where he mentionsRead MoreTheory on Control of Assets Essay3079 Words à |à 13 Pagespeople in charge and from there a new approach will be looked at. An internal auditing process would consist of a series of questions being asked and compared to the criteria needed, thereafter conclusions would be drawn up and a plan put in place. Examples: ( The process of internal auditing ) âž ¢ Condition: What is the particular problem identified? âž ¢ Criteria: What is the standard that was not met? The standard may be a company policy or other benchmark. âž ¢ Cause: Why did the problem occurRead MoreTinted Windows Advantages And Disadvantages2097 Words à |à 9 Pagescoolness caused by shelter from direct sunlight, It helps protect yourself from harmful radiation to sunlight and shade can be also talking about shades as a color. Especially with regard to how light or dark it is or as distinguished from one nearly like it, pertaining to tint or hues of a specific color. If shades sound soothing for you, we also use sunglasses to protect our eyes. Then if we are convinced that shades are helpful in protecting us from certain danger why is it a violation to put upRead MoreThe Political Reform Of A Democracy Essay1909 Words à |à 8 Pageseighteen were allowed to be part of Athensââ¬â¢ political affairs. This Athenian democracy was separated into three parts: ââ¬Å"the ekklesia - a sovereign governing body that wrote laws and dictated foreign policy; the boule - a council of representatives from the ten Athenian tribes; and the d ikasteria - the popular courts in which citizens argued cases before a group of lottery-selected jurors.â⬠Cleisthenesââ¬â¢ democracy only survived for two centuries. However, his political reform of a democracy is oneRead MoreEssay on Hackers vs. Crackers3187 Words à |à 13 PagesHackers vs. Crackers Introduction When you hear the word hacker, you probably think of a nerdy, teen-aged boy sitting behind a computer with sinister plans for his attack flowing through the keystrokes of his fingers. You probably think of a techno-criminal defacing websites, shutting down computer systems, stealing money or confidential information-basically a threat to society. But these descriptions may describe someone else enterely. Many in the computer community contend that this criminalRead MoreHobbit Shake Guide6595 Words à |à 27 Pagesutterly respectable hobbit with a secret desire for adventure. Bilbo receives a visit from Gandalf the wizard. The next Wednesday Gandalf returns for tea, bringing with him a party of thirteen dwarves led by Thorin Oakenshield. Despite misgivings on both sides, on Gandalfs recommendation the dwarves hire Bilbo as Burglar on an expedition to the Lonely Mountain, where they plan to recover their ancestral treasure from the dragon Smaug. Comprehension Questions 1.What is Gandalfs reputation? 2.What kindRead MoreThe Hobbit Double Entry Journal Prompts3406 Words à |à 14 Pagestrouble, if he got into itâ⬠(Tolkien 196) ââ¬Å"I have absolutely no use for dragon-guarded treasures and the whole lot could stay here forever, if only I could wake up and find this beastly tunnel was my own front-hall at homeâ⬠(Tolkien 198) ââ¬Å"â⬠¦but rising from the near side of the rocky floor there is a great glow. The glow of the Smaug!â⬠(Tolkien 200) I had to chew this quote up a little bit and ponder upon it. A side of the dwarves that has not yet been shown is expressed here. I believe it is greed.Read MoreUnderstanding And Report The Signs Of Workplace Violence10320 Words à |à 42 Pages Understand Report the Signs of Workplace Violence An important presentation for all employees of The ABC Company Self-Study Student Workbook Table of Contents Why Take this Course 4 Defining the Workplace 5 What is Workplace Violence? 5 What is Workplace Violence? 6 The High Price of Workplace Violence 7 True or False? 7 Occupational Risk Factors 8 Occupational Groups Most at Risk 9 Prevention Strategies 10 Risk Factors Where I Work 11 Assessing Risk Factors:
Thursday, May 7, 2020
Methods to Counter Terrorism - 2293 Words
TERRORISM AND MEASURES TO CTR THIS THREAT TERRORISM AND MEASURES TO CTR THIS THREAT Introduction 1. The menace of terrorism is the most clear and present danger at this point in time. The word terrorism was first used in France to describe a new system of government adopted during the French revolution (1789-1799). The reign of terror was intended to promote democracy and popular rule by ridding the revolution of its enemies and thereby purifying it. However, the oppression and violent excesses of the terror transformed it into a feared instrument of the state. From that time on, terrorism has had a decidedly negative connotation. 2. The U.S. government says democracy is necessary to inoculate Iraq and Afghanistan against the return ofâ⬠¦show more contentâ⬠¦(This may be termed as the Principle of Necessity). b. Preventive Action. The sole objective of the use of force is to suppress actual disturbances . Force must never be applied with punitive intent, nor as a reprisal. Action must not be taken in one place with the object of creating an effect in another place. It must also be borne in mind always that no soldier can punish a civilian except under martial law. c. Minimum Force. A commander must be firm and must never flinch from suing sufficient force, but he must never use more force than is absolutely necessary to achieve the immediate military aim. d. Strict Observance of the Law. Military persnnel must comply with the law implicity , in letter as well as spirit, and in doing so they must act calmly and impartially. e. Protecting Loyal Citizens. Special care must be taken not to endanger harmles s citizens in any manner. The protection of those citizens who are loyal to the governement or the state, is vitally important. f. Maintenance of Public Morale. No effort should be spared to win and foster public confidence and support. In the same way, effort must be made to neutralise public support to the dissidents and to damage their reputation. g. Recording of Accureate Evidence. It is theShow MoreRelatedwar and terrorism833 Words à |à 4 Pagesï » ¿P3: Outline the terrorism methods used by key terrorist organisations Terrorism is an act that threatens or carries out violence with the intention to disrupt, kill or coerce against a body or nation in order to impose will. This means that a lot of groups use this method to get what they want. The groups use a variety of methods, groups such as: Al Qaeda, who mainly use suicide bombing methods, this is good, because it means there are lots of deaths. This leads to scare and forcing the GovernmentRead MoreA Brief Note On Boko Haram And The Fulani Militants1533 Words à |à 7 Pageswith an attempt to cause mass casualties. However in late December 2013, an anarchist organisation in Greece intended to carry out a CBRN scenario involving food poisoning. In 2014 there was a significant increase in private citizens as victims of terrorism. These attacks were mainly carried out by three groups: Boko Haram, Fulani militants and ISIL. All groups use different tactics. Boko Haram and the Fulani militants mainly use automatic weapons and have very high levels of fatalities per attack,Read MoreTerrorism : Terrorism And Terrorism1626 Words à |à 7 PagesTerrorism can be categorized as ââ¬Å"the use of intentionally indiscriminate violence as means to create terror, or fear, to achieve a political, religious, or ideological aim (Fortna).â⬠Although there is no formal definition of terrorism, we typically associate the words terrorism and terrorists with acts of violence that are used unlawfully to intimidate in pursuance of political gain. Terrorists do not act at random, but rather use violence to maximize on fear and publicity with a specific goal inRead MoreThe Department Of Homeland Security Essay1483 Words à |à 6 Pageswith te rrorism problem that has a long history in the U.S. Terrorism has been a threat to U.S. security since the 1800. Terrorists continue to use powerful secret communication strategies and unexpected tools to achieve their intention in the U.S. soil. For example, the 9/11 terrorism attack that killed the highest number of American citizens in history succeeded because terrorist used hijacked passenger planes to perform the attack (Lutz and Lutz, 2013). Although the most notorious terrorism activityRead MoreMilitary Science: Irregular Warfare Essay1230 Words à |à 5 Pagesin creating effective strategies for irregular warfare with a particular emphasis on counter-insurgency (COIN) and terrorism. Resources such as time, space, legitimacy and support present themselves as key issues in dealing with insurgency and terrorism and are leveraged by an insurgent or terrorist group to gain an advantage over conventional military forces. Modern day understanding of insurgency and terrorism has become blurred over time and thus it is necessary to make the difference betweenRead MoreThe Middle East, And America s Imperial Ambitions1177 Words à |à 5 Pagesthe construction of the modern Middle East, and its continued involvement in the region. This research question is significant because it interlinks post-colonial studies with contemporary security studies. This link is important because modern terrorism and the instability in the Middle East cannot be explored without reference to past Western foreign policies. Because the Western influence ââ¬â in the case of this paper, the United States ââ¬â is partially responsible for the instability the Middle EastRead MoreThe Attack On The World Trade Center1562 Words à |à 7 Pagesindividuals plan an act of terrorism is less likely to alert law enforcement, compare to when a whole terrorist cell plans an attack, because the more people involved the less secretive the attack. Furthermore extreme right are using firearms and other easily obtainable weapons, because acquiring materials to build a bomb is much harder, more time consuming and send red flags to proper authority. Although extreme right and religious extremist are the most violent form of terrorism groups the both haveRead MoreImpact of Globalization on Terrorism1245 Words à |à 5 Pages Since terrorism has taken the impact of globalization it is leaving the world in a war of terror and a desperate effort to unite against the growing terrorist groups. After the numerous, tragic world wide events stemmed by terrorism such as: 9/11, bombing of the London subway, and the Beslan school hostage crisis, the world has vastly changed itsââ¬â¢ mentality of dealing with the future. The globe is forced to unite against an emerging threat, and is conjointly cutting funding for terrorism throughRead MoreThe Importance Of Communication, Intelligence, And Planning1680 Words à |à 7 Pages Cynthia Howard The Importance of Communication, Intelligence, and Planning to Prevent Terrorism Word Count: Dr. Leerburger The Importance of Communication, Intelligence, and Planning to Prevent Terrorism Terrorism is a growing threat to America and other Countries that is causing more deaths, injuries, and destruction to property and infrastructures. There are ways to reduce the effects of terrorist incidents by using intelligence, communication, and planning. The use of intelligenceRead MoreFight Terrorism without Infringing Human Rights Essay716 Words à |à 3 PagesThe fight against terrorism has always raised concerns that the methods used by States may infringe human rights. As one leading academic, Professor Martin Scheinin,[1] has said ââ¬Å"Governments have often felt tempted to depart from â⬠¦ the fundamental rights of the individual when confronted with acts of terrorismâ⬠¦.â⬠[2] Many leading world figures have stated that the fight against terrorism can be conducted without infringing human rights. For example, Ban Ki Moon, the Secretary General of the United
Wednesday, May 6, 2020
Dtmf Remote Appliance Control System Using Mobile Phone Free Essays
CHAPTER 1 INTRODUCTION This project ââ¬Å"DTMF REMOTE APPLIANCE CONTROL SYSTEM USING MOBILE PHONEâ⬠is used to control appliances which are far away from the user using mobile phone. The aim of the proposed system is to develop a cost effective solution that will provide controlling of home appliances remotely and enable home security against intrusion in the absence of homeowner. The devices connected as home and office appliances consume electrical power and they should be controlled as well as turn on /off if required. We will write a custom essay sample on Dtmf Remote Appliance Control System Using Mobile Phone or any similar topic only for you Order Now Most of the time, it was done manually. Now it is a necessity to control devices more effectively and efficiently at anytime from anywhere. Take an instant when we are going to office and suddenly remembered that to switch off the microwave oven we fell convenient if we could switch off without going back to home, in such situations this project comes to our rescue. In this system, we are going to develop a cellular phone based home/office appliance controller for controlling arbitrary devices. This includes a mobile phone which is connected to the system via head set. To activate the mobile phone unit on the system, a call is to be made and as the call is answered (auto answer mode), in response the user would enter a password to access the system to control devices. As the caller presses the specific button on the keypad, it results in turning ON or OFF specific device and the device switching is achieved by relays. In this project, we designed a basic model and it is used to control 4 lights using a mobile phone, micro-controller and transceiver. The maximum number of devices that can be operated will be the number of buttons present on the keypad of mobile phone. . 1 Block diagram: Figure 1. 1: Block Diagram Fig 1. 1 represents the block diagram of DTMF Remote Appliance Control System using Mobile phone, used to control the appliances present at a distance. Brief Description of Hardware Modules: The DTMF Remote Appliance Control System consists of 1. Mobile Phone 2. MT8888 DTMF Transceiver 3. Philips 89C51 Micro-controller 4. Liquid Crystal Dis play 5. Power Supply Unit 6. Relay Driver 7. Relays 8. Devices 1. 2. 1 Mobile Phone: Mobile Phone is used as a media to instruct the micro controller to power ON/OFF the appliances. The mobile phone used here is Nokia 6030 as it has the required features and is interfaced with the transceiver through ear phones. 1. 2. 2 MT8888 DTMF Transceiver: The MT8888C is a monolithic DTMF transceiver with call progress filter. The transceiver consists of transmitter and receiver. The DTMF signals are transmitted through transmitter and they are received by the mobile phone and decoded using a DTMF receiver/decoder ICââ¬â¢s. 1. 2. 3 PHILIPS 89C51 Micro Controller: The PHILIPS 89C51 is a low cost micro-controller. It has a 40 pin configuration and contains non volatile Flash memory of 64KB which is both parallel programmable and serial in system programmable memory. 1. 2. 4 LCD display: The LCD unit receives character codes (8 bits per character) from a microprocessor or microcomputer, latches the codes to its display data RAM (80 byte DD RAM for storing 80 characters), transforms each character code into a 5Ãâ"7 dot matrix character pattern, and displays the characters on its LCD screen. 1. 2. 5 Power Supply Unit: The power supply unit is used to provide a constant 5V supply to different ICââ¬â¢s. This is a standard circuit using external 12V DC adapter and fixed 3-pin voltage regulator. Diode is added in series to avoid reverse voltage. 1. 2. 6 Relay Driver: The ULN2003 is a high-voltage, high-current darling ton driver comprising of seven NPN darling ton pairs. For high input impedance, we may use two transistors to form a darling ton pair and this pair in CC configuration provides input impedance as high as 2Mohms. 1. 2. 7 Relays: Relays are remote control electrical switches that are controlled by another switch, such as a horn switch or a computer as in a power train control module. Relays allow a small current flow circuit to control a high current circuit. 1. 2. 8 Devices: The devices can be micro-wave oven, bulbs, fans, air cooler, etc which are far away from the user. The micro-controller plays the intelligent part in controlling these devices. 1. 3 Working: This project is used to control the appliances present at a distance using a mobile phone. The first step is the user should make a call to the mobile phone, which is in auto answer mode and thus call gets connected. The user presses the digits present over the keypad of his phone for controlling the appliances present at home or office. Whenever a button is pressed a tone is generated and it is transferred to the mobile phone present in the home or office, which is interfaced with the DTMF transceiver. The DTMF receiver decodes the tone generated and it activates the controller accordingly. The controller operates the devices according to the coding set by the user. The status of the devices whether they are ON/OFF is indicated in the LCD. CHAPTER 2 MT8888 DTMF TRANSCEIVER Introduction: The MT8888C is a monolithic DTMF transceiver with call progress filter. It is fabricated using CMOS technology and it offers low power consumption and high reliability. The receiver section is based upon the industry standard MT8870 DTMF receiver, while the transmitter utilizes a switched capacitor D/A converter for low distortion, high accuracy DTMF signaling. Internal counters provide a burst mode such that tone bursts can be transmitted with precise timing. A call progress filter can be selected allowing a microprocessor to analyze call progress tones. The MT8888C utilizes an Intel micro interface, which allows the device to be connected to a number of popular microcontrollers with minimal external logic. The applications of DTMF transceiver include credit card systems, paging systems, repeater systems, interconnector dialers, mobile radio and personal computers. In our project, it is used for decoding the tone generated by the user when he presses a button of the keypad. After decoding the tone, it is given to the microcontroller for controlling the appliances. Features: The features of MT8888 DTMF transceiver include: 20 pin DIP package Central office quality DTMF transmitter/receiver Low power consumption High speed Intel micro interface Compatible with 6800 microprocessors Adjustable guard time Automatic tone burst mode Call progress tone detection up to -30dbm Microprocessor port Pin Diagram Description: Figure 2. 1: DTMF Pin Diagram Figure 2. 1 shows the pin diagram of MT8888 and the description of the monolithic IC is as shown in the following table 2. 1. Table 2. 1: Description of Pins of DTMF Transceiver Pin NoNameDescription 1IN+Non-inverting op-amp input 2IN-Inverting op-amp input. 3GSGain Select. Gives access to output of front end differential amplifier for connection of feedback resistor. 4VrefReference Voltage output (VDD/2). VSSGround (0V). 6OSC1DTMF clock/oscillator input. Connect a 4. 7M? resistor to VSS if crystal oscillator is used. 7OSC2Oscillator output. A 3. 579545 MHz crystal connected between OSC1 and OSC2 completes the internal oscillator circuit. Leave open circuit when OSC1 is driven externally. 8TONEOutput from internal DTMF transmitter. 9WRWrite microprocessor input. TTL compatible. 10CSChip Select input. Active Low. This sig nal must be qualified externally by address latch enable (ALE) signal. 11RS0Register Select input. TTL compatible. 12RDRead microprocessor input. TTL compatible. 3IRQ/CPInterrupt Request/Call Progress (open drain) output. In interrupt mode, this output goes low when a valid DTMF tone burst has been transmitted or received. In call progress mode, this pin will output a rectangular signal representative of the input signal applied at the input op-amp. The input signal must be within the bandwidth limits of the call progress filter. 14-17D0-D3Microprocessor Data Bus. High impedance when CS=1or RD=1. TTL compatible. 18EStEarly Steering output. Presents logic high once the digital algorithm has detected a valid tone pair (signal condition). Any momentary loss of signal condition will cause ESt to return to a logic low. 19St/GTSteering Input/Guard Time output (bidirectional). A voltage greater than V ts detected at St causes the device to register the detected tone pair and updated output latch. A voltage less than V tst frees the device to accept a new tone pair. The GT output acts to reset the external steering time-constant; its state is a function of ESt and the voltage on St. 20VDDPositive power supply (5V typical). 2. 4 Functional Description: The MT8888C Integrated DTMF Transceiver consists of a high performance DTMF receiver with an internal gain setting amplifier and a DTMF generator which employs a burst counter to synthesize precise tone bursts and pauses. A call progress mode can be selected so that frequencies within the specified pass band can be detected. The Intel micro interface allows microcontrollers, such as the 8080, 80C31/51 and 8085, to access the MT8888C internal registers. The block diagram of DTMF transceiver is as shown in figure 2. 2. Figure 2. 2: Block Diagram of DTMF Transceiver 2. 5 Call Progress Filter: A call progress mode using the MT8888C can be selected allowing the detection of various tones, which identify the progress of a telephone call on the network. The call progress tone input and DTMF input are common; however call progress tones can only be detected when CP mode has been selected. DTMF signals cannot be detected if CP mode has been selected. Figure 2. 3 indicates the useful detect bandwidth of the call progress filter. Frequencies presented to the input, which are within the ââ¬Ëacceptââ¬â¢ bandwidth limits of the filter are hard limited by a high gain comparator with the IRQ/CP pin serving as the output. The square wave output obtained from the Schmitt trigger can be analyzed by a microprocessor or counter arrangement to determine the nature of the call progress tone being detected. Frequencies which are in the ââ¬Ërejectââ¬â¢ area will not be detected and consequently the IRQ/CP pin will remain low. Figure 2. 3: Call Progress Response 2. 6 DTMF generator: The DTMF transmitter employed in the MT8888C is capable of generating all sixteen standard DTMF tone pairs with low distortion and high accuracy. All frequencies are derived from an external 3. 579545 MHz crystal. The sinusoidal waveforms for the individual tones are digitally synthesized using row and column programmable dividers and switched capacitor D/A converters. The row and column tones are mixed and filtered providing a DTMF signal with low total harmonic distortion and high accuracy. To specify a DTMF signal, data conforming to the encoding format shown in Table 2. 2 must be written to the transmit Data Register. Note that this is the same as the receiver output code. The individual tones which are generated (f LOW and f HIGH) are referred to as Low Group and High Group tones. As seen from the table, the low group frequencies are 697, 770, 852 and 941 Hz. The high group frequencies are 1209, 1336, 1477 and 1633 Hz. Typically; the high group to low group amplitude ratio (twist) is 2 dB to compensate for high group attenuation on long loops. The period of each tone consists of 32 equal time segments. The period of a tone is controlled by varying the length of these time segments. During write operations to the Transmit Data Register the 4 bit data on the bus is latched and converted to 2 of 8 coding for use by the programmable divider circuitry. This code is used to specify a time segment length, which will ultimately determine the frequency of the tone. When the divider reaches the appropriate count, as determined by the input code, a reset pulse is issued and the counter starts again. The number of time segments is fixed at 32; however, by varying the segment length as described above the frequency can also be varied. The divider output clocks another counter, which addresses the sine wave lookup ROM. Table 2. 2: DTMF Tones FLOWFHIGHDIGITD3D2D1D0 697120910001 697133620010 697147730011 770120940100 770133650101 770147760110 852120970111 52133681000 852147791001 941133601010 9411209*1011 9411477#1100 6971633A1101 7701633B1110 8521633C1111 9411633D0000 Note: 0= LOGIC LOW, 1= LOGIC HIGH The lookup table contains codes which are used by the switched capacitor D/A converter to obtain discrete and highly accurate DC voltage levels. Two identical circuits are employed to produce row and column tones, which are then mixed using a l ow noise summing amplifier. The oscillator described needs no ââ¬Å"start-upâ⬠time as in other DTMF generators since the crystal oscillator is running continuously thus providing a high degree of tone burst accuracy. A bandwidth limiting filter is incorporated and serves to attenuate distortion products above 8 kHz. It can be seen from Figure 2. 4 that the distortion products are very low in amplitude. Figure 2. 4: Spectrum Plot 2. 7 Receiver Section: Separation of the low and high group tones is achieved by applying the DTMF signal to the inputs of two sixth-order switched capacitor band pass filters, the bandwidths of which correspond to the low and high group frequencies. These filters incorporate notches at 350 Hz and 440 Hz for exceptional dial tone rejection. Each filter output is followed by a single order switched capacitor filter section, which smoothes the signals prior to limiting. Limiting is performed by high-gain comparators which are provided with hysterics to prevent detection of unwanted low-level signals. The outputs of the comparators provide full rail logic swings at the frequencies of the incoming DTMF signals. Following the filter section is a decoder employing digital counting techniques to determine the frequencies of the incoming tones and to verify that they correspond to standard DTMF frequencies. A complex averaging algorithm protects against tone simulation by extraneous signals such as voice while providing tolerance to small frequency deviations and variations. This averaging algorithm has been developed to ensure an optimum combination of immunity to talk-off and tolerance to the presence of interfering frequencies (third tones) and noise. When the detector recognizes the presence of two valid tones (this is referred to as the ââ¬Å"signal conditionâ⬠in some industry specifications) the ââ¬Å"Early Steeringâ⬠(ESt) output will go to an active state. Any subsequent loss of signal condition will cause ESt to assume an inactive state. The DTMF keypad is as shown in figure 2. 5 Figure 2. 5: Typical DTMF Keypad 123A697 Hz 456B770 Hz 789C852 Hz *0#D941 Hz 1209 Hz1336 Hz1477 Hz1633 Hz 2. 8 Burst Mode: In certain telephony applications it is required that DTMF signals being generated are of a specific duration determined either by the particular application or by any one of the exchange transmitter specifications currently existing. Standard DTMF signal timing can be accomplished by making use of the Burst Mode. The transmitter is capable of issuing symmetric bursts/pauses of predetermined duration. This burst/pause duration is 51 msà ± 1 ms, which is a standard interval for auto dialer and central office applications. After the burst/pause has been issued, the appropriate bit is set in the Status Register indicating that the transmitter is ready for more data. The timing described above is available when DTMF mode has been selected. However, when CP mode (Call Progress mode)is selected, the burst/pause duration is doubled to 102 ms à ±2 ms. Note that when CP mode and Burst mode have been selected, DTMF tones may be transmitted only and not received. In applications where a non-standard burst/pause time is desirable, a software timing loop or external timer can be used to provide the timing pulses when the burst mode is disabled by enabling and disabling the transmitter. Microprocessor interface: The MT8888C incorporates an Intel microprocessor interface which is compatible with fast versions (16 MHz) of the 80C51. No wait cycles need to be inserted. Figure 2. 6 and Figure 2. are the timing diagrams for the Intel 8031, 8051 and 8085 (5 MHz) microcontrollers. By NANDing the address latch enable (ALE) output with the high-byte address (P2) decode output, CS is generated. Figure 2. 8 summarizes the connection of these Intel processors to the MT8888C transceiver. Figure 2. 6: 8031/8051/8085 Read Timing Diagram Figure 2. 7: 8031/8051/8085 Write Timing Diagram Figure 2. 8: MT8888C Interface Connections for Various Intel Micros The microprocessor interface provides access to five internal registers. The read-only Receive Data Register contains the decoded output of the last valid DTMF digit received. Data entered into the write-only Transmit Data Register will determine which tone pair is to be generated. Transceiver control is accomplished with two control registers (see Table 2. 3 and Table 2. 4), CRA and CRB, which have the same address. A write operation to CRB is executed by first setting the most significant bit (b3) in CRA. The following write operation to the same address will then be directed to CRB, and subsequent write cycles will be directed back to CRA. The read-only status register indicates the current transceiver state (see Table 2. 5). Table 2. 3: Control Register A Description BITNAME DESCRIPTION b0TOUTTone Output Control. Logic high enables the tone output; a logic low turns the tone output off. This bit controls all transmit tone functions. b1CP/DTMFCall Progress or DTMF Mode Select. A logic high enables the receive call progress mode; a logic low enables DTMF mode. In CP mode a rectangular wave representation of the received tone signal will be present on the IRQ/CP output pin if IRQ has been enabled (Control Register A,b2=1). In order to be detected, CP signals must be within the bandwidth specified in the AC Electrical Characteristics for Call Progress. Note: DTMF signals cannot be detected when CP mode is selected. b2IRQInterrupt Enable. A logic high enables the interrupt function; a logic low when either 1) a valid DTMF signal has been received for a valid guard time duration, or 2) the transmitter is ready for more data (burst mode only). b3RSELRegister Select. A logic high selects control register B for the next write cycle to the control register address. After writing to control register B, the following control register write cycle will be directed to control register A. Table 2. 4: Control Register B Description BITNAME DESCRIPTION b0 BURSTBurst Mode Select. Logic high de-activates burst mode; a logic low enables burst mode. When activated, the digital code representing a DTMF signal can be written to the transmit register, which will result in a transmit DTMF tone burst and pause of equal durations (typically 51msec). Following the pause, the status register will be updated (b1-Transmit Data Register Empty) and an interrupt will occur if the interrupt mode has been enabled. When CP mode (control register A, b1) is enabled the normal tone burst and pause durations are extended from a typical duration of 51msec to 102 msec. When BURST is high (de-activated) the transmit tone burst duration is determined by the TOUT bit (control register A, b0). b1TESTTest Mode Control. Logic high enables the test mode; a logic low de-activates the test mode. When TEST is enabled and DTMF mode is selected (control register A, b1=0), the signal present on the IRQ/CP pin will be analogous to the state of the delayed steering bit of the status register. 2 S/DSingle or Dual Tone Generation. Logic high selects the single tone output; a logic low selects the dual tone output. The single tone generation function registers further selection of either the row or column tones (Low or high group) through the C/R bit (control register B,b3). b3 C/RColumn or Row tone select. Logic high selects a column tone output, a logic low selects a row tone output. This function is used in conjunc tion with the S/D bit (control register B, b2). Table 2. 5: Status Register Description BITNAMESTATUS OF FLAGSTATUS FLAG CLEARED 0IRQInterrupt has occurred. Bit one (b1) or bit two (b2) is set. Interrupt is inactive. Cleared after status register is read. b1Transmit data register empty(Burst Mode only)Pause duration has terminated and transmitter is ready for new data. Cleared after Status Register is read or when in non-burst mode. b2Receive Data Register FullValid data is in the Receive Data Register. Cleared after Status Register is read. b3 Delayed SteeringSet upon the valid detection in the absence of a DTMF signal. Cleared upon the detection of a valid DTMF signal. A software reset must be included at the beginning of all programs to initialize the control registers upon power-up or power reset (see Figure 19). Refer to Tables 4-7 for bit descriptions of the two control registers. The multiplexed IRQ/CP pin can be programmed to generate an interrupt upon validation of DTMF signals or when the transmitter is ready for more data (burst mode only). Alternatively, this pin can be configured to provide a square wave output of the call progress signal. The IRQ/CP pin is an open drain output and requires an external pull-up resistor. 2. DTMF Registers and initialization: The DTMF has two control registers, one transmits register, one receives register, and one status register. Along with this there is a data buffer which is the entry point for the data for the DTMF to communicate with the microcontroller depending upon the give control signals on the DTMF control pins like rs0,r/w, and the data from the data buffer is communicated with the DTMF. The c ombination of rs0 and r/w pins will give the following result as shown in table 2. 6. Table 2. 6: DTMF Internal Registers RS0R/WFUNCTION 00Write to Transmit Data Register 1Read from Receive Data Register 10Write to Control Register 11Read from Status Register Initialization of DTMF: A software reset must be included at the beginning of all programs to initialize the control registers after power up. The initialization procedure should be implemented 100ms after power up. Description Control Data CS RS0 R/W b3 b2 b1 b0 Read status register 0 1 1 x x x Write to control register 0 1 0 0 0 0 0 Write to control register 0 1 0 0 0 0 0 Write to control register 0 1 0 1 0 0 0 Write to control register 0 1 0 0 0 0 0 Read status register 0 1 1 x x x x Transmission using DTMF: The DTMF has to receive a command to transmit and then the data to send. Consider an example of sending a 50 ms tone- 50 ms pause burst. The procedure is as follows. CS RS0 R/W b3 b2 b1 b0 1. Write to Control Register A 0 1 0 1 0 0 1 (Tone out, DTMF, IRQ, Select Control Register B) 2) Write to Control Register B 0 1 0 0 0 0 0 (Burst mode) 3) Write to Transmit Data Register 0 0 0 0 1 1 1 (Send a digit 7) Reception using DTMF: Reception is carried out by checking the status of DTMF for a valid data in receive register and then receive it by a command. The procedure is as follows. 1) Read the Status Register 0 1 1 x x x x -if bit 1 is set, the Tx is ready for the next tone, in which caseâ⬠¦ Write to Transmit Register 0 0 0 0 1 0 1 (Send a digit 5) -if bit 2 is set, a DTMF tone has been received, in which caseâ⬠¦. Read the Receive Data Register 0 0 1 x x x -if both bits are setâ⬠¦ Read the Receive Data Register 0 0 1 x x x x Write to Transmit Data Register 0 0 0 0 1 0 1 Thus the initialization of DTMF Transceiver is done using the internal registers according to ur requirements and then it is used for decoding the tones generated by the user. CHAPTER 3 THE MICROCONTROLLER 3. 1 Introduction: Phillips 89C51 contains a non-volatile FLASH program memory that is both parallel programmable and serial in system and in application programmable. It is an 8-bit micro controller from MHS-51 Intel family with 4K bytes of flash and 128 bytes of internal RAM. It has 40-pin configuration and it takes input from the external sources and routes them to the appropriate devices as programmed in it. Features: The features of PHILIPS 89C51 include: 80C51 Central Processing Unit On-chip FLASH Program Memory Speed up to 33 MHz Fully Static Operation RAM expandable externally up to 64 Kbytes Four interrupt priority levels Six interrupt sources Four 8-bit I/O ports Full-duplex enhanced UART Framing error detection Automatic address recognition Power Control Modes Clock can be stopped and resumed Idle Mode Power down Mode Programmable clock out Second DPTR register Asynchronous Port Reset Watchdog Timer Pin Diagram Description: VCC: Supply voltage. GND: Ground. Port 0: Port 0 is an 8-bit open-drain bi-directional I/O port. As an output port, each pin can sink eight TTL inputs. When 1s are written to port 0 pins, the pins can be used as high impedance inputs. Port 0 may also be configured to be the multiplexed low order address/data bus during accesses to external program and data memory. In this mode P0 has internal pull-ups. Port 0 also receives the code bytes during Flash programming, and outputs the code bytes during program verification. External pull-ups are required during program verification. Figure 3. 1: Pin Diagram of 89C51 Micro Controller Port 1: Port 1 is an 8-bit bi-directional I/O port with internal pull-ups. The Port 1 output buffers can sink/source four TTL inputs. When 1s are written to Port 1 pins they are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 1 pins that are externally being pulled low will source current (IIL) because of the internal pull-ups. Port 1 also receives the low-order address bytes during Flash programming and verification. Port 2: Port 2 is an 8-bit bi-directional I/O port with internal pull-ups. The Port 2 output buffers can sink/source four TTL inputs. When 1s are written to Port 2 pins they are pulled high by the internal pull-ups and can be used as inputs. As inputs Port 2 pins that are externally being pulled low will source current (IIL) because of the internal pull-ups. Port 2 emits the high-order address byte during fetches from external program memory and during accesses to external data memory that uses 16-bit addresses (MOVX @DPTR). In this application, it uses strong internal pull-ups when emitting 1s. During accesses to external data memory that uses 8-bit addresses (MOVX @ RI), Port 2 emits the contents of the P2 Special Function Register. Port 2 also receives the high-order address bits and some control signals during Flash programming and verification. Port 3: Port 3 is an 8-bit bi-directional I/O port with internal pull-ups. The Port 3 output buffers can sink/source four TTL inputs. When 1s are written to Port 3 pins they are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 3 pins that are externally being pulled low will source current (IIL) because of the pull-ups. Port 3 also serves the functions of various special features of the AT89C51 as listed below: Port 3 also receives some control signals for Flash programming and verification. The alternate functions of Port 3 are as shown in table 3. 1. Table 3. 1: Alternate Functions of Port 3 Port PinAlternate Functions P3. 0RXD(serial input port) P3. 1TXD(serial output port) P3. 2INT0(external interrupt 0) P3. 3INT1(external interrupt 1) P3. 4T0(Timer 0 external interrupt) P3. 5T1(Timer 1 external interrupt) P3. WR(external data memory write strobe) P3. 7RD(external data memory read strobe) RST: Reset input. A high on this pin for two machine cycles while the oscillator is running resets the device. ALE/PROG: Address Latch Enable output pulse for latching the low byte of the address during accesses to external memory. This pin is also the program pulse input (PROG) during Flash programmin g. In normal operation ALE is emitted at a constant rate of 1/6 the oscillator frequency, and may be used for external timing or clocking purposes. Note, however, that one ALE pulse is skipped during each access to external Data Memory. If desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With the bit set, ALE is active only during a MOVX or MOVC instruction. Otherwise, the pin is weakly pulled high. Setting the ALE-disable bit has no effect if the microcontroller is in external execution mode. PSEN: Program Store Enable is the read strobe to external program memory. When the AT89C51 is executing code from external program memory, PSEN is activated twice each machine cycle, except that two PSEN activations are skipped during each access to external data memory. EA/VPP: External Access Enable. EA must be strapped to GND in order to enable the device to fetch code from external program memory locations starting at 0000H up to FFFFH. Note, however, that if lock bit 1 is programmed, EA will be internally latched on reset. EA should be strapped to VCC for internal program executions. This pin also receives the 12-volt programming enable voltage (VPP) during Flash programming, for parts that require12-volt VPP. XTAL1: Input to the inverting oscillator amplifier and input to the internal clock operating circuit. XTAL2: Output from the inverting oscillator amplifier. Oscillator Characteristics: XTAL1 and XTAL2 are the input and output, respectively, of an inverting amplifier which can be configured for use as an on-chip oscillator, as shown in Figure 3. 2. Either a quartz crystal or ceramic resonator may be used. To drive the device from an external clock source, XTAL2 should be left unconnected while XTAL1 is driven . There are no requirements on the duty cycle of the external clock signal, since the input to the internal clocking circuitry is through a divide-by-two flip-flop, but minimum and maximum voltage high and low time specifications must be observed. Figure 3. 2: Crystal Oscillator Architecture of PHILIPS 89C51: The architecture of PHILIPS 89C51 is as shown in figure 3. 3 below and the modes of operation include idle mode and power down mode. Idle Mode: In idle mode, the CPU puts itself to sleep while all the on chip peripherals remain active. The mode is invoked by software. The content of the on-chip RAM and all the special functions registers remain unchanged during this mode. The idle mode can be terminated by any enabled interrupt or by a hardware reset. It should be noted that when idle is terminated by a hardware reset, the device normally resumes program execution, from where it left off, up to two machine cycles before the internal reset algorithm takes control. On-chip hardware inhibits access to internal RAM in this event, but access to the port pins is not inhibited. To eliminate the possibility of an unexpected write to a port pin when Idle is terminated by reset, the instruction following the one that invokes Idle should not be one that writes to a port pin or to external memory. Figure 3. 3: Architecture of PHILIPS 89C51 Micro-controller Power-down Mode: In the power-down mode, the oscillator is stopped, and the instruction that invokes power-down is the last instruction executed. The on-chip RAM and Special Function Registers retain their values until the power-down mode is terminated. The only exit from power-down is a hardware reset. Reset redefines the SFRs but does not change the on-chip RAM. The reset should not be activated before VCC is restored to its normal operating level and must be held active long enough to allow the oscillator to restart and stabilize. Table 3. 2: Idle and power down modes ModeProgram MemoryALEPSENPORT0PORT1PORT2PORT3 IdleInternal11DataDataDataData IdleExternal11FloatDataAddressData Power downInternal00DataDataDataData Power downExternal00FloatDataDataData Timer 0 and Timer 1: The ââ¬Å"Timerâ⬠or ââ¬Å"Counterâ⬠function is selected by control bits C/T in the Special Function Register TMOD. These two Timer/Counters have four operating modes, which are selected by bit-pairs (M1, M0) in TMOD. Modes 0, 1, and 2 are the same for both Timers/Counters. Mode 3 is different. Memory Organization: During the runtime, micro controller uses two different types of memory: one for holding the program being executed (ROM memory), and the other for temporary storage of data and auxiliary variables (RAM memory). Depending on the particular model from 8051 family, this is usually few kilobytes of ROM and 128/256 bytes of RAM. This amount is built-in and is sufficient for common tasks performed ââ¬Å"independentlyâ⬠by the MCU. However, 8051 can address up to 64KB of external memory. CHAPTER 4 SERIAL COMMUNICATION 4. 1 Introduction: When a micro processor communicates with the outside world, it provides data in byte-size chunks. In some cases, such as printers, the information is simply grabbed from the 8bit data bus of the printer. This can work only if the cable is not too long, since long cables diminish and ever distort signals. Furthermore, an 8-bit data path is expensive. For these reasons, serial communication is used for transferring data between two systems located at distances of hundreds of feet to millions of miles apart. The fact that in serial communication a single data line is used instead of the 8bit data line of parallel communication makes it not only much cheaper but also makes it possible for two computers located in two different cities to communicate over the telephone. Serial data communication uses two methods, asynchronous and synchronous. The asynchronous method transfers a block of data at a time while the synchronous data transfers a single byte at a time. It a mean possible to write software to use either of these methods, but the programs can be tedious and long. For this reason, there are special IC chips made by many manufacturers for serial data communications. This chips are commonly referred to as UART (Universal Asynchronous Receiver Transmitter) and USART (Universal Synchronous Asynchronous Receiver Transmitter). The ARM has built in UARTs. Figure 4. 1: Serial Communication 4. Asynchronous Serial Communication Data Framing: The data coming in at the receiving end of the data line in a serial data transfer is all 0ââ¬â¢s and 1ââ¬â¢s; it is difficult to make sense of data unless the sender and receiver agree on a set of rules, a protocol, on how the data is packed, how many bits constitute the character, and when the data begins and ends. Start and Stop bits: Asynchronous serial data communication is w idely used for character orientation transmissions. In the asynchronous method, each character is placed in between start and stop bits. This is called framing. In data framing for asynchronous communications, the data, such as ASCII characters, are packed in between a start bit and a stop bit. The start bit is always one bit but the stop bit can be one or two bits. The start bit is always a 0 and the stop bit is 1. Parity bit: In some systems in order to maintain data integrity, the parity bit of the character byte is included in the data frame. This means that for each character we have a single parity bit in addition to start bit and stop bits. The parity bit is odd or even. In case of an odd parity bit the number of data bits including parity bit is even. Data transfer rate: The rate of data transfer in serial data communication is stated in bps(bits per second). Another widely used terminology for bps in baud rate. Baud rate is defined as the number of signal changes per second. As far as the conductor wire is concerned, the baud rates as bps are the same. Data framing: Figure 4. 2: Data Framing 4. 3 RS232 Standard: To allow compatibility among the data communication equipment made by various manufacturers; an interfacing standard called RS232, was set by the Electronic Industries Association (EIA) in 1960. RS232 is the most widely used serial input-output interfacing standard. In RS232, a 1 is represented by -3 to -25v, while a 0 bit is +3 to +25v. To connect any RS232 to a micro controller, voltage converters such as MAX232 are used. Max 232 IC chips are commonly referred to as line drivers. RS232 connectors: The RS232 connector is as shown in figure 4. 3 and the working of pins is described in table 4. 1 Figure 4. 3: RS232 Connector Table 4. 1: Pin description of RS232 Connector Pin noFunction 1CD-Carrier Detector 2RxD-Receive Data 3TxD-Transmit Data DTR-Data Terminal Request 5GND-Signal Ground 6DSR-Data Set Ready 7RTS-Request To Send 8CTS-Clear To Send 9RI-Ring Indicator MAX 232: The RS 232 is not compatible with microcontroller, so a line driver converts the RS 232ââ¬â¢s signals to TTL voltage levels. The MAX232 is a dual driver/receiver that includes a capacitive voltage generator to supply TIA/EIA-232-F voltage levels from a single 5v supply. Each receiver converts TIA/EIA-232 -F inputs to 5v TTL/CMOS levels. These receivers have a typical threshold of 1. 3v, a typical hysteresis of 0. v, and can accept à ±30v inputs. Each driver converts TTL/CMOS input levels into TIA/EIA-232-F levels. Transfer between microcontroller and RS 232c: Figure 4. 4: RS232 Level to TTL Level Conversion CHAPTER 5 LIQUID CRYSTAL DISPLAY 5. 1 Introduction: The LCD unit receives character codes (8 bits per character) from a microprocessor or microcomputer, latches the codes to its display data RAM (80-byteDD RAM for storing 80 characters), transforms each character code into a 5Ãâ"7 dot matrix character pattern, and displays the characters on its LCD screen. The LCD unit incorporates a character generator ROM which produces 160 different 5Ãâ"7 dot-matrix character patterns. The unit also provides a character generator RAM (64 bytes) through which the user may define up to eight additional 5Ãâ"7 dot matrix character patterns, as required by the application. To display a character, positional data is sent via the data bus from the microcontroller to the LCD unit, where it is written into the instruction register. A character code is then sent and written into the Data register. The LCD unit displays the corresponding character pattern in the specified position. The LCD unit can either increment or decrement the display position automatically after each character entry, so that only successive characters codes need to be entered to display a continuous character string. The display/cursor shift instruction allows the entry of characters in either the left-to-right or right to left direction. 5. 2 Features: The features of liquid crystal display include: Interface with either 4-bit or 8-bit microprocessor. Display data RAM. 80 x8 bits (80 characters). Character generator ROM 160 different 5 x7 dot-matrix character patterns. Character generator RAM. different user programmed 5 x7 dot-matrix patterns. Display data RAM and character generator RAM may be accessed by the microprocessor. Numerous instructions. Clear Display, Cursor Home, Display ON/OFF, Cursor. ON/OFF, Blink Character, Cursor Shift, Display Shift. Built-in reset circuit is triggered at power ON. 5. 3 Pin diagram: Figure 5. 1: LCD Pin Diagram 5. 4 Pin description: VCC, VSS and VEE: While VCC and VSS provide + 5 V on and ground, respectively, VEE is used for controlling LCD contrast. RS: register select There are two very important registers inside LCD. The RS pin is used for their selection as follows. Is RS= 0, the instruction command code register is selected, allowing the user to send a command such as clear display, Cursor at home, etc. if RS=1 the data register is selected, allowing the user to send data to be displayed on the LCD. R/W: read/write R/W input allows the user to write information to the LCD or read information from it. R/W=1 when reading; R/W=0 when writing. E: enable The LCD to latch information presented to its data pins uses the enable pin. When data is supplied to data pins, a high to low pulse must be applied to this pin in order for the LCD to latch in the data present at the data pins. This pulse must be a minimum of 450 ns wide. D0-D7: The 8-bit data pins, D0-D7, are used to send information to the LCD or read the contest of the LCD internal registers. To display letters and numbers, we send ASCII codes for the letters A-Z, a-z, and numbers 0-9 to these pins while making RS=1. We also use RS= 0to check the busy flag bit to see if the LCD ready to receive. The busy flag isD7 and can be read when R/W=1 and RS= 0, as follows: if R/w=1 and RS = 0. When D7 =1, the LCD is busy taking care of internal operations and will not accept any new information. WhenD7=0, the LCD is ready to receive new information. . 5 LCD Commands: The commands given to the LCD are as shown in table 5. 1 Table 5. 1: LCD Commands HEXREGISTER 01Clear display screen 02Return home 04Decrement cursor (shift cursor to left) 06Increment cursor (shift cursor to right) 05Shift Display right 07Shift display left 08Display off, cursor off 0ADisplay off, cursor on 0CDisplay on, cursor off 0EDisplay on, curs or blinking 0FDisplay on, cursor blinking 10Shift cursor position to left 14Shift cursor position to right 18Shift the entire display to the left 1CShift the entire display to the right 80Force cursor to beginning of 1st line C0Force cursor to beginning of 2nd line 382 lines and 5Ãâ"7 matrix 5. 6 Power Supply Unit: The input to the circuit is applied from the regulated power supply. The a. c. input i. e. , 230V from the mains supply is step down by the transformer to 12V and is fed to a rectifier. The output obtained from the rectifier is a pulsating d. c voltage. So in order to get a pure d. c voltage, the output voltage from the rectifier is fed to a filter to remove any a. c components present even after rectification. Now, this voltage is given to a voltage regulator to obtain a pure constant dc voltage. Figure 5. : Power Supply Unit 5. 6. 1 Transformer: Usually, DC voltages are required to operate various electronic equipment and these voltages are 5V, 9V or 12V. But these voltages cannot be obtained directly. Thus the a. c input available at the mains supply i. e. , 230V is to be brought down to the required voltage level. This is done by a transformer. Thus, a step down transformer is employed to decrease the voltage to a required level. 5. 6. 2 Rectifier: The output from the transformer is fed to the rectifier. It converts A. C. into pulsating D. C. The rectifier may be a half wave or a full wave ectifier. In this project, a bridge rectifier is used because of its merits like good stability and full wave rectification. 5. 6. 3 Filter: Capacitive filter is used in this project. It removes the ripples from the output of rectifier and smoothens the D. C. Output received from this filter is constant until the mains voltage and load is maintained constant. 5. 6. 4 Voltage Regulator: As the name itself implies, it regulates the input applied to it. A voltage regulator is an electrical regulator designed to automatically maintain a constant voltage level. In this project, power supply of 5V and 12V are required. In order to obtain these voltage levels, 7805 and 7812 voltage regulators are to be used. The first number 78 represents positive supply and the numbers 05, 12 represent the required output voltage levels. Three-Terminal Voltage Regulator: Fig 5. 3 shows the basic connection of a three-terminal voltage regulator IC to a load. The fixed voltage regulator has an unregulated dc input voltage, Vi, applied to one input terminal, a regulated output dc voltage, Vo, from a second terminal, with the third terminal connected to ground. For a selected regulator, IC device specifications list a voltage range over which the input voltage can vary to maintain a regulated output voltage over a range of load current. The specifications also list the amount of output voltage change resulting from a change in load current (load regulation) or in input voltage (line regulation). GND4 Figure 5. 3: Fixed Positive Voltage Regulator CHAPTER 6 RELAY DRIVER, RELAYS DEVICES 6. 1 Introduction: The ULN2003 is a high-voltage, high-current darling ton driver comprising of seven NPN darling ton pairs. For high input impedance we may use two ransistors to form a Darlington pair. This pair in CC configuration provides input impedance as high as 2Mohms. The input signal varies with the base current of the first transistor this produces variation in the collector current in the first transistor. The emitter load of the first stage is the input resistance of the second stage. The emitter current of the first transistor is the base current of the second transistor. The IC is as shown in figure 6. 1. . Figure 6. 1: ULN2003 Relay driver 6. 2 Features: The features of ULN2003 relay driver are: Output current (single output) 500mA MAX High sustaining voltage output 50v MIN Output clamp diodes Input compatible with various types of logic 6. 3 Pin Diagram Description: Fig 6. 2: Pin diagram of ULN 2003 The IC is of 16-pin and is a monolithic linear IC. It has 7darlington pairs internally of 7 inputs and 7 outputs i. e. 1 to 7 are inputs of Darlington pairs and 10 to 16 are the outputs, 8-pin is ground and 9-pin is common freewheeling diode. Applications: The ULN 2003 driver is used in Relays Hammer Lamps Display (LED) drivers 6. 4 Relays: 6. 4. 1 Introduction: The relay is a device that acts upon the same fundamental principle as the solenoid. The difference between a relay and a solenoid is that a relay does not have a movable core (plunger) while the solenoid does. Where multiple relays are used, several circuits may be controlled once. Relays are electrically operated control switches, and are classified according to their use as POWER RELAYS or CONTROL RELAYS. Power relays are called CONTACTORS, control relays are usually known simply as relays. The function of a contactor is to use a relatively small amount of electrical power to control the switching of a large amount of power. Control relays are frequently used in the control of low power circuits. . 4. 2 Electromagnetic Relay: Relays in which the relative movements of their mechanical components produce preset responses under the effect of the current in the input circuit are called electromagnetic relays. The relay used in this project is electromagnetic relay which is shown in figure 6. 4. 2. Figure 6. 3: Electromagnetic Relay 6. 4. 3 Operation: OperationAndWhen a certain voltage or current is applied to both ends of the coil of an electromagnetic relay, the magnetic flux passes through the magnetic circuit composed of iron core, yoke iron, armature iron and the magnetic circuit operation air gap. Under the influence of magnetic field, armature iron is attracted to iron core pole face thus propelling normally closed contact to open and normally open contact to close, when the applied voltage or current at both ends of the coil is lower than a certain value and mechanical reactance is greater than electromagnetic attraction, armature iron is restored to the original state and normally open contact opens and normally closed contact closes. 6. 4. 4 Components of Electromagnetic Relay: Electromagnetic relay is composed of magnetic circuit system, contact system and return mechanism. Magnetic circuit system is made up of such parts as iron core, yoke iron, armature iron and coil. Contact system is composed of such parts as static contact spring, movable contact spring and contact seat. Return mechanism is made up of return springs of draw springs. Figure 6. 4: Components of Electromagnetic Relay 6. 5 Devices: The devices include microwave oven, electric bulbs, fans, motors, coolers, etc. Any of the devices can be operated from anywhere by interfacing them to the microcontroller. CHAPTER 7 COMPONENTS INTERFACING WITH MICROCONTROLLER 7. MT8888C Interfacing With Microcontroller: The MT8888 DTMF transceiver is interfaced to the microcontroller port P2. The data pins of transceiver are interfaced with P2. 0-P2. 3 and the control pins are connected to P2. 4-P2. 7 as shown in figure 7. 1. PHILIPS 89C51MT8888 Figure 7. 1: Interfacing MT8888 with the microcontroller 7. 2 LCD Interfacing with the Microcontroller: Depending on how many lines are used for connection to the m icrocontroller, there are 8bit and 4bit LCD modes. The appropriate mode is determined at the beginning of the process in a phase called ââ¬Å"initializationâ⬠. In the first case, the data are transferred through outputs D0-D7 as it has been already explained. In case of 4-bit LED mode, for the sake of saving valuable I/O pins of the microcontroller, there are only 4 higher bits (D4-D7) used for communication, while other may be left unconnected. Consequently, each data is sent to LCD in two steps: four higher bits are sent first (that normally would be sent through lines D4-D7), four lower bits are sent afterwards. With the help of initialization, LCD will correctly connect and interpret each data received. Besides, with regards to the fact that data are rarely read from LCD (data mainly are transferred from microcontroller to LCD) one more I/O pin may be saved by simple connecting R/W pin to the Ground. Such saving has its price. Even though message displaying will be normally performed, it will not be possible to read from busy flag since it is not possible to read from display. Here we used 8 bit LCD. The LCD is interfaced with microcontroller port P0. The data pins of LCD are interfaced with the Port 0 pins P0. 0-P0. 7 and the control pins of LCD are interfaced with Port 1 pins P1. -P1. 7 as shown in figure 7. 2. PHILIPS 89C51 LCD Figure 7. 2: Interfacing LCD to the Microcontroller Algorithm to send data to LCD: 1. Make R/W low 2. Make RS=0; if data byte is command RS=1; if data byte is data (ASCII value) 3. Place data byte on data register 4. Pulse E (HIGH to LOW) 5. Repeat the steps to send another data byte 7. 3 Interfacing devices with the microcontroller: The devices that are t o be controlled are interfaced with port 1 of microcontroller. Here we used four devices and they are interfaced to P1. 0-P1. 3 as shown in figure 7. 3. Figure 7. 3: Interfacing devices with the microcontroller CHAPTER 8 SOFTWARE DETAILS 8. 1 Keil à µVision 4: Keil was founded in 1986 to market the add-on products for development tools provided by many of the silicon vendors. Keil implemented the first C compiler designed from the ground up specifically for 8051 microcontroller. Keil provides broad range of development tools like ANSI C Compiler, macro assembler, debuggers and simulators, linkers, IDE library managers, real time operating system evaluation boards for 8051 ARM families. It is used to write programs for an application. The programs can be written in embedded C or in assembly language. 8. 1. 1 Evaluation of Keil Software: Start the à µVision Program Select new à µVision Project from the project menu Give the project name: prjname and save it with extension*. uvproj as shown in fig 8. 1. 1a After saving another window will be displayed to select the target device. In that select LPC 2478 from NXP (founded by Philips) from the data base given Select it and click OK a new project with target file will be created. Select the newâ⬠¦ from the file menu Type your c file Select saveâ⬠¦ from file menu. The first time you save the program a dialog box will pop-up and allow you to name your file and file type. Save program with file name: xxxx. c The file type mentioned at last (. c) means embedded c language. Right click on source group and click add files to source group. This will add files to project as shown in figure 8. 1. 1(b) Right click on source group and select build all target files. This will create HEX file needed for ARM. Figure 8. 1: Starting a New Project in KEIL Figure 8. 1 indicates how to start a new project in KEIL software to develop a program. Select the name of the project ant save it as . v2, then a new project is created as shown in figure. Figure 8. 2: Adding Files to the Source Group Figure 8. 2 shows how we should add files to the source group after we created a new project using KEIL micro vision. Figure 8. 3: Program written in the File added to the Source Group Figure 8. 3 shows the picture after the program file is being added to the source group so t hat an ASM file is created for the source file where code is written. 8. 1. 2 Using the Keil dscope Debugger: Select start /stop debug session from debug menu The debug program will start a new session as shown in figure 8. 1. 1(d) Select File, load object file from the program menu. Change the file type to HEX Select your hex file, e. g. xxxx. Hex Click OK You should now see the source code of the file typed in earlier Select Peripherals, GPIO Fast Interface, Ports required from the program menu. So that you can see the how output varies on ports. Select Port 0, Port 1, Port 2, Port 3 and port 4. Select Peripherals, UART, UARTs required from the program menu. So that you can see the how output varies on UARTs. Select UART0, UART1, UART2 and UART3. Click on go to see the real time update of the I/O ports. Click on stop when you are finished. You can also single step through you program or set break points at locations that you want the debugger to stop at. To set a breakpoint, double click on the line. Figure 8. 4: Debugging the code using Start/Stop Debug Session Figure 8. 4 shows that after the ASM file is created, it should be debugged using Start/Stop Debug Session. The program debuuging starts when we press the start and it can be ended using stop. Figure 8. 5: After Debugging, the value of the registers 8. 2 Flash Magic Software: The flash magic software is one of the best known microcontroller programs dumping software. It has the compatibility with the KEIL software. The HEX file generated by the KEIL is used by the FLASH MAGIC to program the microcontroller. The software uses the computer serial port to transmit data into microcontroller. It has many options like appending the code, erasing the memory, reading from the microcontroller etc to dump the code program first the FLASH MAGIC has to be provided with necessary information about the target, the band rate supported, the clock frequency,etc. ,then the software checks for the device connected to the computer serial port. If the target is not connected, an error is generated. The software then checks for the available memory and the size of file to be dumped. Then it checks whether the target (microcontroller) is in ISP (In ââ¬âsystem programming) mode or not. If everything is fine then, it starts writing into the microcontroller using the serial data transfer pins Txd and Rxd pins on the microcontroller. After the code is loaded into the microcontroller, even the power goes off , the code will not be lost as it is stored in the EEPROM which is not volatile. Giving the RESET will restart the program execution from the beginning. We have seen that using a high level language improves the readability of the program, makes the programming process more efficient, and makes it possible to write portable code. The compiler generates the assembly code and therefore places a large role in determining the actual CPU operation. Because compilers are not as smart as programmers are, the machine code generated by compiler if typically larger and less efficient than the machine code generated from assembly source code. This may be disconcerting to some programmers, but it is not a good enough reason to avoid high level languages. Instead, it means that you must know yourcompiler and know how the different parts of your C code will be implemented. Figure 8. 2: Flash Magic for dumping the code into the microcontroller Flow Chart: NO YES YESYES NO YES YES NO YESYES NO YESYES NO 8. 4 Source Code: /***DTMF REMOTE APPLIANCE CONTROL SYSTEM USING MOBILE PHONE***/ /*****************************BATCH ââ¬â A2***********************************/ /********DTMF INITIALISATION********/ Dtmf_data equ p2 Dtmf_wr equ p2. 7 Dtmf_cs equ p2. 6 Dtmf_rs0 equ p2. 4 Dtmf_rd equ p2. 5 /********LCD INITIALISATION*********/ Lcddata equ p0 Lcd_rs equ p1. 5 Lcd_rw equ p1. 6 Lcd_en equ p1. 7 /*******DEVICES INITIALISATION********/ dev1 equ p1. 0 dev2 equ p1. 1 dev3 equ p1. 2 dev4 equ p1. 3 psswrd bit 21 org 00h mov p1,#0f0h mov r0,#50h call Dtmf_init call Lcd_init /*call DispLine1 mov dptr,#Proj_name call Disp_string call delay call DispLine2 mov dptr,#Proj_name1 call Disp_string call delay call DispLine3 mov dptr,#Proj_name2 call Disp_string call delay call Clr_Display call DispLine1 mov dptr,#College_name call Disp_string call delay call Clr_Display call DispLine2 mov dptr,#College_location call Disp_string call delay call Clr_Display call DispLine1 mov dptr,#TEAM call Disp_string call DispLine2 ov dptr,#NAME1 call Disp_string call DispLine3 mov dptr,#NAME2 call Disp_string call delay call Clr_Display call DispLine1 mov dptr,#NAME3 call Disp_string call DispLine2 mov dptr,#NAME4 call Disp_string call DispLine3 mov dptr,#NAME5 call Disp_string call DispLine4 mov dptr,#NAME6 call Disp_string call delay call Clr_Display */ main: call Clr_Display mov dptr, #myname call Disp_string clr psswrd Rx_tone: mov a,#8fh call Lcd_cmnd mov r0,#50h mov r7,#00h store_tone: call delay50ms clr a call read_sta_reg jnb acc. 2,store_tone call read_rx_data_reg anl a,#0fh jb psswrd,compare mov @r0,a mov a,#â⬠*â⬠call Lcd_data_out inc r0 inc r7 jne r7,#04,store_tone mov r0,#50h mov a,@r0 cjne a,#1,invalid_Tone inc r0 mov a,@r0 cjne a,#2,invalid_Tone inc r0 mov a,@r0 cjne a,#3,invalid_Tone inc r0 mov a,@r0 cjne a,#4,invalid_Tone call Clr_Display mov dptr,#yesOk call Disp_string setb psswrd jmp store_tone invalid_Tone: call Clr_Display mov dptr,#NotOk call Disp_string clr psswrd call delay50ms call delay50ms jmp main /***********************************************/ compare: cjne a,#01,label1 setb dev1 call Clr_Display call DispLine1 mov dptr,#labela call Disp_string setb psswrd jmp store_tone label1:cjne a,#02,label2 setb dev2 call Clr_Display call DispLine2 mov dptr,#labelb all Disp_string setb psswrd jmp store_tone label2:cjne a,#03,label3 setb dev3 call Clr_Display call DispLine3 mov dptr,#labelc call Disp_string setb psswrd jmp store_tone label3:cjne a,#04,label4 setb dev4 call Clr_Display call DispLine4 mov dptr,#labeld call Disp_string setb psswrd jmp store_tone label4:cjne a,#05,label5 clr dev1 call Clr_Display call DispLine1 mov dptr,#labele call Disp_string setb psswrd jmp store_tone label5:cjne a,#06,label6 clr dev2 call Clr_Display call DispLine2 mov dptr,#labelf call Disp_string setb psswrd jmp store_tone label6:cjne a,#07,label7 clr dev3 call Clr_Display call DispLine3 mov dptr,#labelg all Disp_string setb psswrd jmp store_tone label7:cjne a,#08,label8 clr dev4 call Clr_Display call DispLine4 mov dptr,#labelh call Disp_string setb psswrd label8: jmp store_tone /*ââ¬âââ¬âââ¬âââ¬â-Dtmf_initââ¬âââ¬âââ¬âââ¬âââ¬âââ¬âââ¬â-*/ Dtmf_init: call read_sta_reg mov a,#00h call write_cnt_reg mov a,#00h call write_cnt_reg mov a,#08h call write_cnt_reg mov a,#00h call write_cnt_reg ca ll read_sta_reg ret read_sta_reg: mov Dtmf_data,#0ffh setb Dtmf_rs0 setb Dtmf_wr clr Dtmf_rd clr Dtmf_cs nop nop mov a,Dtmf_data setb Dtmf_cs setb Dtmf_rd ret write_cnt_reg: mov Dtmf_data,a setb Dtmf_rd clr Dtmf_wr setb Dtmf_rs0 clr Dtmf_cs nop nop etb Dtmf_cs setb Dtmf_wr ret read_rx_data_reg: mov Dtmf_data,#0ffh clr Dtmf_rs0 setb Dtmf_wr clr Dtmf_rd clr Dtmf_cs nop nop mov a,Dtmf_data setb Dtmf_cs setb Dtmf_rd ret /***********Lcd Display*******************/ Lcd_init: mov a,#30h call Lcd_cmnd mov a,#38h call Lcd_cmnd mov a,#06h call Lcd_cmnd mov a,#0ch call Lcd_cmnd mov a,#01h call Lcd_cmnd ret Lcd_cmnd: call delay_50ms mov Lcddata,a clr Lcd_rs clr Lcd_rw setb Lcd_en nop nop clr Lcd_en ret Lcd_data_out: call delay_50ms mov Lcddata,a setb Lcd_rs clr Lcd_rw setb Lcd_en nop nop clr Lcd_en ret Disp_string: clr a movc a,@a+dptr jz exit call delay_50ms call Lcd_data_out nc dptr jmp Disp_string exit:ret /*****************************************************/ /***************************** ************************/ ;routine for clearing display Clr_Display: mov a,#01h call lcd_cmnd ret /****************************************************/ /****************************************************/ ;this routine is for display in different lines DispLine1: mov a,#80h call LCD_Cmnd ret DispLine2: mov a,#0C0h call LCD_Cmnd ret DispLine3: mov a,#94h call LCD_Cmnd ret DispLine4: mov a,#0D4h call LCD_Cmnd ret /*****************************************************/ delay: call Delay50ms call Delay50ms all Delay50ms call Delay50ms call Delay50ms ret delay50ms: mov r2,#5 back2:mov r1,#200 back1:mov r5,#250 back:djnz r5,back djnz r1,back1 djnz r2,back2 ret delay_50ms: mov r4,#20 back4:mov r3,#250 back3:djnz r3,back3 djnz r4,back4 ret /*ââ¬âââ¬âââ¬âââ¬âââ¬âââ¬âââ¬âââ¬âââ¬âââ¬âââ¬âââ¬â-*/ ;Display String data Proj_name: DB ââ¬Å"DTMF REMOTE APPLIANCE ââ¬Å",0 Proj_name1: DBââ¬Å"CONTROL SYSTEMâ⬠, 0 Proj_name2:DBâ⬠USING MOBI LE PHONEâ⬠, 0 College_name:DB ââ¬Å"MIC COLLEGE OF TECHNOLOGY ââ¬Å", 0 College_location: DB â⬠KANCHIKACHERLA ââ¬Å", 0 TEAM:DB â⬠DEVELOPED ââ¬Å", 0 NAME1: DB â⬠BY ââ¬Å", 0 NAME2: DB â⬠A2 BATCH ââ¬Å", 0 NAME3: DB â⬠LAVANYA ââ¬Å", 0 NAME4: DB â⬠SIRISHA ââ¬Å", 0 NAME5: DB â⬠PAVAN KUMAR ââ¬Å", 0 NAME6: DB â⬠KISHORE ââ¬Å", 0 myname: DB ââ¬Å"ENTER PASSWORD:â⬠,0h yesOk: DB ââ¬Å"VALID PASSWORDâ⬠,0h NotOk: DB ââ¬Å"INVALID PASSWORDâ⬠, 0h labela:db â⬠DEVICE1 ON ââ¬Å",0 labelb:db â⬠DEVICE2 ON ââ¬Å",0 labelc:db â⬠DEVICE3 ON ââ¬Å",0 labeld:db â⬠DEVICE4 ON ââ¬Å",0 labele:db â⬠DEVICE1 OFF ââ¬Å",0 labelf:db â⬠DEVICE2 OFF ââ¬Å",0 labelg:db â⬠DEVICE3 OFF ââ¬Å",0 labelh:db â⬠DEVICE4 OFF ââ¬Å",0 end CHAPTER 9 ADVANTAGES APPLICATIONS 9. 1 Advantages: Increased productivity Low cost Reduces power consumption Virtual control of appliances High security 9. Disadvantages: No acknowledgement Switch-device pair should be known Network failure 9. 3 Applications: Other applications of this circuit include Agriculture Industry Colleges Schools Future Enhancement: Acknowledgement of the deviceâ⠬â¢s initial condition through SMS. This system can be expanded to provide control over the GPRS. CONCLUSION This project ââ¬Å"DTMF REMOTE APPLIANCE CONTROL SYSTEM USING MOBILE PHONEâ⬠overcomes the limitations of Wireless Domestic Automation which uses a transmitter and receiver to control the home appliances. It resembles a virtual human controlling the remote appliances using a control unit and a mobile phone. It mainly uses DTMF transceiver for decoding the tones generated by the mobile phone, which is given to the micro-controller to control the appliances. The remote appliances control system using mobile phone will one day become a reality and it may revolutionize our way of living. The wide areas of application include controlling the appliances like microwave oven, lighting fans, lights, etc. Another major application is industrial automation as it reduces the power consumption and is of low cost. As this system is implemented using in 2G communication network, the video data cannot be obtained. Future work includes research on the robot control system in 3G communication networks which facilitates controlling the remote robot using DTMF of mobile phone, with video data from the remote mobile robotââ¬â¢s camera. The Future enhancement also includes control of GPRS system using this system. REFERENCES Text Books: The 8051 Micro Controller architecture and embedded systems by Mazidi and Mazidi. Other References: www. atmel. com www. alldatasheets. com www. electronicshub. com www. philips. com International Journal of Electrical Computer Sciences IJECS Vol: 9 No: 10 How to cite Dtmf Remote Appliance Control System Using Mobile Phone, Papers
Monday, April 27, 2020
The Trip To The New England Colonies free essay sample
Essay, Research Paper The Trip to The New England Colonies My trip started off with the 30 twenty-four hours ocean trip across the mighty Atlantic. Not cognizing that I would be sent to the well established settlement of Jamestown. I would be remaining with the mean household. They are to allow me remain on history of rent from my publishing house in England. My tenant, a well developed adult male. He runs a silverworker store. He is besides an creative person. I am certain he will demo me pieces of his work. His married woman, a really friendly lady from the studies. She is half Indian. They have 2 boies. Both good built and are really gracious. They are immature grownups. So far in twenty-four hours 12 of my 30 twenty-four hours ocean trip I don? Ts have any illness symptoms. I had seen many people eating icky nutrient and non cognizing it. I was afraid so I ate every bit small as possible. We will write a custom essay sample on The Trip To The New England Colonies or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page I knew I could do it. Finally twenty-four hours 28 had reached. I was excited to be off the seashore of Jamestown. I figured that by the clip we reached at the dock that we would be in for the dainty of fresh nutrient. The H2O on board is yellow and it stinks. The nutrient is turning this so called hair. It was awful to eat but we had nil else. It was past midnight and I cant slumber due to the crowded floors. I hear a voice, # 8220 ; I heard we? ve reached the point. # 8221 ; I began to acquire aroused and over whelmed. I eventually could eat something fresh. I ran up to the deck non cognizing that the captain wasn? T in his cabin. He looked up to the cat on the Crow? s nest. He said, # 8220 ; Sir I see land. # 8221 ; I neer think it would go on. I made it. The Sun was get downing to come out and light began to uncover land. I could see the garrison but it was a weak position. I see the people at the seashore line wave and happy to see the riders. I couldn? T Tell who I was to accommodate with but I thought I had an thought. There was a nice household standing in the far left. I think that they new what I looked like. After a hebdomad had gone by I got used to the life. I helped out with my portion of jobs and in the store. I helped out with the male childs analyzing. I didn? T know that here they learn how to read from the Bible. After a few months had past I began to observe about the household? s traditions and things they do. I began to see Mrs. Wise have more and more Quilting Bee parties. The Boys do more work around the store. Besides Mr. Wise ease off working every bit hard. He must get downing to base on balls the concern on T o the male childs. At the Quilting Bee parties Mrs. Wise would hold several ladies over and hold a party out of doing a comforter. Most of these parties had around 20 people. The put together several people because it makes it faster to do comforters. I noticed several misss larning from their female parents how to sew and so 4th. I besides noted about there importance of Church. I saw that their discourses lasted 2 or 3 hours. Back in England they lasted around 20 proceedingss. They would socialise and observe major events during church besides. I noted that the Indians there taught the settlers really good. They taught them how to pin down fish, and happen wild herbs and leafy vegetables. Although subsequently Roger Williams a clergy was about arrested in 1636 for back uping land rights for Native Americans. I saw many enslaved people. The Wises did non believe in bondage. African Americans were either slaves or apprenticed retainers. In 1775 I learned they were one fifth of the population. Trading was of import to the settlers. Merchants helped to interrupt the barrier between settlements. They helped to do better integrity. I noted about the towns category differences. Most were in-between category. Native Americans ranked at the underside of the category list. They were neer treated with regard for all the thing s that they did for settlers. Gentry were known as the rich people. The apparels told about the adult male. I notice the turning struggle traveling on between Native Americans and Settler in the struggle over the land. The settler killed the Native Americans by disease, guns, and intoxicant. The Natives didn? T have an unsusceptibility to the disease like the settlers did. The settlers matrimony rites were really different than that in England. The Quakers didn? Ts have a curate at the nuptials. They besides married at place non at church. Marriage was for life. Wifes could non run off with out the hubby giving a divorce. Their spiritual rites were different excessively. They had a Sabbath twenty-four hours on Sunday. It was required that you be at that place unless you were making work. Their version of the bible Teachs instructions for the settlers. Virginia daring was the first English babe born in America. So in all the New England settlements are first-class in faith and work. They have developed really good. They largely follow the same guidelines as England except with a few corrections and curves to regulations. 350
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