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Dual tone multiple frequency


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Dual tone multiple frequency

  1. 1. ON EMBEDDED SYSTEM AND ROBOTICS (PLC Institute of Electronics ,Rohini ,Delhi)SUBMITTED TO: – SUBMITTED BY:–Mr. Tajender Malik Neeraj Khatri(H.O.D.:– ECE Deptt.) (926/ECE/10) (ECE Department)Neeraj Khatri Page 1(926/ECE/10)
  2. 2. ACKNOWLEDGEMENTI would like to add a few heartfelt words for the people who were part ofthis training report in numerous ways. People who gave unending supportright from the stage of training report idea were conceived. In particular, Iam extremely grateful to PLC INSTITUTE OF ELECTRONICS ,Rohini ,Delhi for providing me with an excellent opportunity of undergoingsummer training for the duration of six weeks.I express my effusive thanks to Mr. B.P. ARUN (Teacher & Mentor) andother staff members. With their expert guidance and kind help this trainingwould have been a distant dream.Finally a special thanks to all the Members of PLCIE, Rohini, Delhi Whohelp me lot to carried out the project report and to compete my trainingsuccessfully.Last but not the least; I thank my teacher, friends and my family membersfor their constant encouragement. NEERAJ KHATRI (926/ECE/10)Neeraj Khatri Page 2(926/ECE/10)
  3. 3. PREFACEIndustrial training is must for every student pursuing professional degreebecause the ultimate goal of every student is to get the information theindustrial training helps us to get an idea of things.We should known in order to get a good job i.e. have a good professionalcarrier. Industrial training teaches us a lot of things. It helps us to know thekind of environment we would be getting in an industry and help us to getwith the kind of environment.Industrial training helps us to know what kind of grade an engineer ofspecific branch plays in an industry. It help us to get used to working ingroups of known people in it teach us team work because my work inindustrial is accomplished by a group and not an individual.In totality the industrial teaches us industrial ethics. Some advance technicalknowledge how and help us to acquired with industrial working style.Neeraj Khatri Page 3(926/ECE/10)
  4. 4. CONTENTS S.No. Topic Page 1. Introduction 5 2. Technology Used 9 3. Electronics Part 14 4. Mechanical Part 31 5. Software Part 36 6. Snapshot 39 7. Conclusion 44Neeraj Khatri Page 4(926/ECE/10)
  5. 5. INTRODUCTIONNeeraj Khatri Page 5(926/ECE/10)
  6. 6. INTRODUCTION :Radio control (often abbreviated to R/C or simply RC) is the use ofradio signals to remotely control a device. The term is usedfrequently to refer to the control of model vehicles from a hand-heldradio transmitter. Industrial, military, and scientific researchorganizations make [traffic] use of radio-controlled vehicles as well. A remote control vehicle is defined as any mobile device that is controlledby a means that does not restrict its motion with an origin external tothe device. This is often a radio control device, cable between controland vehicle, or an infrared controller. A remote control vehicle (Alsocalled as RCV) differs from a robot in that the RCV is alwayscontrolled by a human and takes no positive action autonomously.One of the key technologies which underpin this field is that of remotevehicle control. It is vital that a vehicle should be capable of proceedingaccurately to a target area; maneuvering within that area to fulfill itsmission andreturning equally accurately and safely to base.Recently, Sony Ericsson released a remote control car that could becontrolled by any Bluetooth cell phone. Radio is the most popularbecause it does not require the vehicle to be limited by the length ofthe cable or in a direct line of sight with the controller (as with theinfrared set-up). Bluetooth is still too expensive and short range to becommercially viable.Neeraj Khatri Page 6(926/ECE/10)
  7. 7. EMBEDDED SYSTEM:An embedded system is a computer system designed for specificcontrol functions within a larger system, often with real-time computingconstraints.It is embedded as part of a complete device often includinghardware and mechanical parts. By contrast, a general-purposecomputer, such as a personal computer (PC), is designed to be flexibleand to meet a wide range of end-user needs. Embedded systems controlmany devices in common use today.Embedded systems contain processing cores that are typicallyeithermicrocontrollers or digital signal processors (DSP).The keycharacteristic, however, is being dedicated to handle a particular task.Since the embedded system is dedicated to specific tasks, designengineers can optimize it to reduce the size and cost of the product andincrease the reliability and performance. Some embedded systems aremass-produced, benefiting fromeconomies of scale.Physically, embedded systems range from portable devices suchas digital watches and MP3 players, to large stationary installationslike traffic lights,factory controllers, or the systems controlling nuclearpower plants. Complexity varies from low, with asingle microcontroller chip, to very high with multipleunits, peripherals and networks mounted inside a large chassis orenclosure.Neeraj Khatri Page 7926/ECE/10
  8. 8. CHARACTERISTICSEmbedded systems are designed to do some specific task, rather than bea general-purpose computer for multiple tasks. Some also have real-time performance constraints that must be met, for reasons such assafety and usability; others may have low or no performancerequirements, allowing the system hardware to be simplified to reducecosts.Embedded systems are not always standalone devices. Many embeddedsystems consist of small, computerized parts within a larger device thatserves a more general purpose. For example, the Gibson RobotGuitar features an embedded system for tuning the strings, but theoverall purpose of the Robot Guitar is, of course, to play music.Similarly, an embedded system in an automobile provides a specificfunction as a subsystem of the car itself.The program instructions written for embedded systems are referred toas firmware, and are stored in read-only memory or Flash memory chips.They run with limited computer hardware resources: little memory,small or non-existent keyboard or screenNeeraj Khatri Page 8926/ECE/10
  9. 9. TECHNOLOGY USEDNeeraj Khatri Page 9926/ECE/10
  10. 10. TECHNOLOGY USEDDual-Tone Multi-Frequency(DTMF):Dual-tone multi-frequency (DTMF) signaling is used fortelecommunication signaling over analog telephone lines in thevoice-frequency band between telephone handsets and othercommunications devices and the switching center. The version ofDTMF used for telephone tone dialing is known by thetrademarked term Touch-Tone (canceled March 13,1984), andis standardized by ITU-T Recommendation . It isalso known in theUK as MF4. Other multi-frequency systems are used forsignaling internal to the Telephone network.As a method of in-band signaling, DTMF tones were also used bycable television broadcasters to indicate the start and stop times oflocal commercial insertion points during station breaks for thebenefit of cable companies. Until better out-of-band signalingequipment was developed in the 1990s, fast, unacknowledged, andloud DTMF tone sequences could be heard during the commercialbreaks of cable channels in the United States and elsewhere.Neeraj Khatri Page 10926/ECE/10
  11. 11. Telephone KeypadThe contemporary keypad is laid out in a 3x4 grid, although theoriginal DTMF keypad had an additional column for four now-defunct menu selector keys. When used to dial a telephonenumber, pressing a single key will produce a pitch consisting of twosimultaneous pure tone sinusoidal frequencies. The row in which thekey appears determines the low frequency, and the columndetermines the high frequency. For example, pressing the[1] key will result in a sound composedof both a 697 and a 1209 hertz (Hz) tone. The originalkeypads had levers inside, so each button activated two contacts.The multiple tones are the reason for calling the systemmultifrequency. These tones are then decoded by the switching centerto determine which key was pressed. A DTMF Telephone KeypadNeeraj Khatri Page 11926/ECE/10
  12. 12. DTMF Keypad Frequencies (With Sound Clips) 1209 Hz 1336 Hz 1477 Hz 1633 Hz 697 Hz 1 2 3 A 770 Hz 4 5 6 B 852 Hz 7 8 9 C 941 Hz * 0 # D DTMF Event Frequencies Event Low Freq. High Freq. Busy Signal 480 Hz 620 Hz Dial Tone 350 Hz 440 Hz Ringback 440 Hz 480 Hz Tone(US)Tones #, *, A, B, C, and DThe engineershad envisioned phones being used to accesscomputers, and surveyed a number of companies to seewhat they would need for this role. This led to the addition ofthe number sign (#, sometimes called !octothorpe! in thiscontext) and asterisk or ’star’ (*) keys as well as a group of keysNeeraj Khatri Page 12926/ECE/10
  13. 13. for menu selection: A, B, C and D. In the end, the lettered keys weredropped from most phones, and it was many years before thesekeys became widely used for vertical service codes such as *67in the United States and Canada suppress caller ID.The U.S. military also used the letters, relabeled, in their nowdefunct Autovon phone system. Here they were used beforedialing the phone in order to give some calls priority, cuttingin over existing calls if need be. The idea was to allow importanttraffic to get through every time. The levels of priority available wereFlash Override (A), Flash (B), Immediate (C), and Priority (D), withFlash Override being the highest priority.Neeraj Khatri Page 13926/ECE/10
  14. 14. ELECTRONICS PARTNeeraj Khatri Page 14926/ECE/10
  17. 17. THIS PROJECTS :RESISTORS:Resistors restrict the flow of electric current, for example a resistor isplaced in series with a light-emitting diode (LED) to limit the currentpassing through the LED.Resistance is measured in ohms, the symbol for ohm is an omega .1 is quite small so resistor values are often given in k and M .1 k = 1000 1 M = 1000000 .CAPACITOR :Neeraj Khatri Page 17926/ECE/10
  18. 18. Capacitors store electric charge. They are used with resistorsin timing circuits because it takes time for a capacitor to fill with charge.They are used to smooth varying DC supplies by acting as a reservoir ofcharge. They are also used in filter circuits because capacitors easilypass AC (changing) signals but they block DC (constant) signals.CapacitanceThis is a measure of a capacitors ability to store charge. A largecapacitance means that more charge can be stored. Capacitance ismeasured in farads, symbol F. However 1F is very large, so prefixes areused to show the smaller values.Three prefixes (multipliers) are used, µ (micro), n (nano) and p (pico): µ means 10-6 (millionth), so 1000000µF = 1F n means 10-9 (thousand-millionth), so 1000nF = 1µF p means 10-12 (million-millionth), so 1000pF = 1NfNeeraj Khatri Page 18926/ECE/10
  19. 19. DIODES:Diodes allow electricity to flow in only one direction. The arrow of thecircuit symbol shows the direction in which the current can flow. Diodesare the electrical version of a valve and early diodes were actually calledvalves.Neeraj Khatri Page 19926/ECE/10
  20. 20. CRYSTAL OSCILLATOR:A crystal oscillator is an electronic oscillator circuit that uses themechanical resonance of a vibrating crystal of piezoelectric material tocreate an electrical signal with a very precise frequency. This frequencyis commonly used to keep track of time (as in quartz wristwatches), toprovide a stable clock signal for digital integrated circuits, and tostabilize frequencies for radio transmitters and receivers. The mostcommon type of piezoelectric resonator used is the quartz crystal, sooscillator circuits designed around them became known as "crystaloscillators." 3.57954 MHz CRYSTALNeeraj Khatri Page 20926/ECE/10
  21. 21. H-BRIDGE:L293D is a dual H-Bridge motor driver. So with one IC, two DC motorscan be interfaced which can be controlled in both clockwise and counterclockwise directions and its direction of motion can also be fixed. Thefour I/O’s can be used to connect up to four DC motors. L293D hasoutput current of 600mA and peak output current of 1.2A per channel.Moreover for the protection of the circuit from back EMF,output diodes are included within the IC. The output supply (VCC2) hasa wide range from 4.5V to 36V, which has made L293D a best choicefor DC motor driver. The name "H-Bridge" is derived from the actualshape of the switching circuit which controls the motion of the motor. Itis also known as "Full Bridge".Neeraj Khatri Page 21926/ECE/10
  22. 22. SNAPSHOT OF H-BRIDGE: PCB OF H-BRIDGE:Neeraj Khatri Page 22926/ECE/10
  23. 23. 8870 DTMF DECODER: MT8870DE ICDTMF KITINTRODUCTION:DTMF means DUAL TONE MULTIPLE FREQUENCY .Thistechnology is widely used and has many applications. One of theapplication is discussed that is mobile controlled robotic carusing DTMF technology . Being able to achieve reliablecommunication is an important open area of research to roboticsas well as other technology areas. As interest in roboticscontinues to grow, robots are increasingly being integrated ineveryday life. The results of this integration are end-userspossessing less and less technical knowledge of the technology.Currently, the primary mode for robot communication uses RF(radio frequency). RF is an obvious choice for communicationsince it allows more. Information to be transferred at smallerdistance. The overall goal of the project is to control robot over along distance using DTMF technology efficiently.Neeraj Khatri Page 23926/ECE/10
  24. 24. DescriptionThe transmitter side is placed in the area which is to besupervised. The receiver section is placed in the operator sidewhich receives the video from the corresponding area.DTMF TONE :The DTMF technique outputs distinct representation of 16 commonalphanumeric characters (0-9, A-D, *, #) on the telephone. The lowestfrequency used is 697Hz and the highest frequency used is1633Hz, as shown in Table.Neeraj Khatri Page 24926/ECE/10
  25. 25. The DTMF keypad is arranged such that each row will have its ownunique tone frequency and also each column will have its own uniquetone frequency. Above is a representation of the typical DTMF keypadand the associated row/column frequencies. By pressing a key, forexample 5, will generate a dual tone consisting of 770 Hz for the lowgroup and 1336 Hz for the high group.DTMF Decoder:The MT-8870 is a DTMF Receiver that integrates both band split filterand decoder functions into a single 18-pin DIP or SOIC package. It ismanufactured using CMOS process technology. The MT-8870 offerslow power consumption (35 mW max) and precise data handling.Its filter section uses switched capacitor technology for both the highand low group filters and for dial tone rejection. Its decoder uses digitalcounting techniques to detect and decode all 16 DTMF tone pairs into aNeeraj Khatri Page 25926/ECE/10
  26. 26. 4-bit code. External component count is minimized by provision of anon-chip differential input amplifier, clock generator, and latched tri-stateinterface bus. Minimal external components required includes a low-cost3.579545 MHz color burst crystal, a timing resistor, and a timingcapacitor.The filter section is used for separation of the low-group and high grouptones and it is achieved by applying the DTMF signal to the inputs oftwo sixth order switched capacitor band pass filters, the bandwidths ofwhich corresponds to the low and high group frequencies. The filtersection also incorporates notches at 350 and 440 Hz for exceptional dialtone rejection. Each filter output is followed by a single order switchedcapacitor filter section which smoothes the signals prior to limiting.Limiting is performed by high-gain comparators which are providedwith hysteresis to prevent detection of unwanted low-level signals. Theoutputs of the comparators provide full rail logic swings at thefrequencies of the incoming DTMF signals. Following the filter sectionis a decoder employing digital counting techniques to determine thefrequencies of the incoming tones and to verify that they correspond tothe standard DTMF frequencies. CIRCUIT DIAGRAMNeeraj Khatri Page 26926/ECE/10
  27. 27. SNAPSHOT OF DTMF: : PCB OF DTMF:Neeraj Khatri Page 27926/ECE/10
  28. 28. 8051 MICROCONTROLLER(AT89S52): Brain of the DTMF 40 Pin IC Actually a small computer Fitted on the Robot. Has Internal RAM , ROM , Microprocessor , Input/output buses , timer , counter and many other things. Code is burned on this IC and Processing is also done here. It has 4 Ports : P0 , P1 , P2 , P3 are shown on next page. Ecah port has 8 Bit. Crystal Oscillator Provides external Frequency.Neeraj Khatri Page 28926/ECE/10
  29. 29. Neeraj Khatri Page 29926/ECE/10
  30. 30. SNAPSHOT OF 8051 MICROCONTROLLER: PCB OF 8051 MICROCONTROLLER:Neeraj Khatri Page 30926/ECE/10
  31. 31. MECHANICAL PARTNeeraj Khatri Page 31926/ECE/10
  32. 32. MECHANICAL PARTS:S.No. Component Quantity Dimension1. Chassis 1 L*B (in inches) 9*72. Wheel 2 Diameter (in cm)73. Nut 7 2-4 inches long4. Bolt 13 As per the dimension of the nut5. Clamps 2 As per the size of dc motor6. Caster wheel 1 Diameter (in cm) 37. DC motor 2 12 volt 100 rpmNeeraj Khatri Page 32926/ECE/10
  33. 33. DC MOTOR:A DC motor is designed to run on DC electric power. Two examples ofpure DC designs are Michael Faradays homopolar motor (which isuncommon), and the ball bearing motor, which is (so far) a novelty. Byfar the most common DC motor types are the brushed and brushlesstypes, which use internal and external commutation respectively toreverse the current in the windings in synchronism with rotation.Neeraj Khatri Page 33926/ECE/10
  34. 34. Most electric motors operate through the interaction of magneticfields and current-carrying conductors to generate force. The reverseprocess, producing electrical energy from mechanical energy, is doneby generators such as an alternator or a dynamo; some electric motorscan also be used as generators, for example, a traction motor on avehicle may perform both tasks. Electric motors and generators arecommonly referred to as electric machines.Electric motors are found in applications as diverse as industrial fans,blowers and pumps, machine tools, household appliances, power tools,and disk drives. They may be powered by direct current, e.g.,a battery powered portable device or motor vehicle, or by alternatingcurrent from a central electrical distribution grid or inverter. Thesmallest motors may be found in electric wristwatches. Medium-sizemotors of highly standardized dimensions and characteristics provideconvenient mechanical power for industrial uses. The very largestelectric motors are used for propulsion of ships, pipeline compressors,and water pumps with ratings in the millions of watts. Electric motorsmay be classified by the source of electric power, by their internalconstruction, by their application, or by the type of motion they give.Features of 12v dc motor: 100RPM 12V DC motors with Gearbox 3000RPM base motor 6mm shaft diameter with internal hole 125gm weight Same size motor available in various rpm 1.2kgcm torque No-load current = 60 mA(Max), Load current = 300 mA(Max)Neeraj Khatri Page 34926/ECE/10
  35. 35. AFTER ASSEMBLING MECHANICAL PARTS :(Snapshot)Neeraj Khatri Page 35926/ECE/10
  36. 36. SOFTWARE PARTNeeraj Khatri Page 36926/ECE/10
  39. 39. SNAPSHOTNeeraj Khatri Page 39926/ECE/10
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  44. 44. CONCLUSIONI am very satisfied with the experience gained during this practicaltraining. I was given the possibility to work hand in hand with otherStudents inside the Institute learning about essentials of EmbeddedSystem.As a student of ELECTRONICS & COMM. ENGINEERING I tried tolearn somewhat concept of the Embedded System which is mainlyconcerned with my focus area.In the technical aspect, we conclude that nothing can be understoodthoroughly without practical knowledge and practice. We observedalmost each process related to casting that we had just studied in books.It was really a fruitful training for us to enhance our knowledge andconfidence level.At last, I would like to say thanks again all staff of the unit who helpedme through my training period.Neeraj Khatri Page 44926/ECE/10