I.K.E Infrared Keyless EntryTeam MembersProblem StatementKey ComponentsBlock DiagramDesign RequirementsFunctionalityUnique Signal KeyingEffective RangePowerPhysical PackagingPhysical CharacteristicsAffordabilitySerial EncodingSerial Encoding / Decoding IC’sTransmitter / Receiver PairSignal Transmitter CircuitExample Input SignalSignal Transmitter CircuitSignal Receiver CircuitContinuing WorkI.K.EInfrared Keyless Entry EE 4512 Senior Design Department of Electrical and Computer Engineering April 10, 2001Design PReviewTeam MembersKenny Reynolds – Team Leader Dr. Ray Winton - AdvisorMembersAdria D. Jones Ray SmithProblem StatementRadio Frequency Keyless Entry (RFKE) does not provide flexible interaction between automobiles and external communication devices. SolutionInfrared Keyless Entry (I.K.E) will provide a flexible way of remote entry as well as allow communication with devices containing infrared IrDa compliant ports.Key Components Optical Signal Transmitter Optical Signal ReceiverAmplification Decode Micro- Controller Specified FunctionBlock DiagramTransmitterIrDA PalmtopIR Standard ReceiverLogicIrIrDA ControlDesign RequirementsFunctionalityUnique Key SignalingEffective RangePowerPhysical PackagingPhysical AttributesPhysical CharacteristicsAffordabilityFunctionality The receiver unit will be able to lock and unlock doors of vehicles with preinstalled power door locks. The receiver unit will also posses the capability of providing other functionality, such as lowering windows.Unique Signal KeyingUnique Signal Keying helps to ensure the system is not compromised. This will be obtained by encrypting the transmission signal and decrypting the signal at the receiver unit. The receiver has to be compliant with Version 1.1 of the IrDA specifications so it may receive infrared signals from third-party communication devices.Effective RangeIt will only be necessary for IKE to be able to operated no less than 20 feet under normal daylight conditions. Communication with third party devices will be limited to two meters due to the requirements of infrared data communication.PowerPower to the receiver will be provided by the automobile’s battery. The operating range will be 10 to 15 VDC and consume no more than 100 mA of current.The transmitter operate by a 6V source and consume no more than 100 mA of current to maximize battery life.Additional current drops will be required from the automobile during locking and unlocking doors.Physical PackagingThe IR receiver unit will be packaged in a box no larger than 5’’ by 5’’ by 2’’. It will contain all components necessary for decryption of the signal and interface with the proper wiring of the vehicle for locking and unlocking the doors.The transmitter unit will be encompassed in a box no larger than 2” by 3” by 0.75’’, small enough to be placed on a key chain with the ignition key while in operation with the car.Physical CharacteristicsThe system must be durable enough to withstand the ruggedness of vehicle travel and user mobility.AffordabilityThe transmitter and receiver units will be packaged and be sold less than $35.00.Serial EncodingThe HOLTEK HT-680 and HT-694 chips will be used to serially encode the signal for IR transmission. 8 control lines, 4 data lines–8 control lines can be tied high, low, or left open.Provides 105,000 possible serial combinations.Varying R1 varies the frequency of oscillation, making countless combinations possible.Serial Encoding / Decoding IC’sHT-680 Serial EncoderHT-694 Serial DecoderTransmitter / Receiver PairHT-680 serial encoder and transmitterSignal Receiver, Amp,and serial decoderSignal Transmitter Circuit1kR2C1 100pfD2D1N75010 R4D6D1N4002D1N4002 D8D7D1N40021k R3Q2N6059Q1C2 100pFD1D1N41481k R1+-6VV1+-V2IR_outputEncoded_SignalExample Input SignalExample input waveform to transmitter circuitSignal Transmitter Circuit Simulated signal input and output from transmitter.Signal Receiver CircuitR83 3 kR 71 MC14 .7 n F1 kR61 0 kR4dD11 nC3C4 2 2 uR3 1 0 kR2 4 74 7R1C21 u fR5 1 0 0 k1+3-2V +4V-1 1LM3 2 4U2 A1+3-2V+4V-1 1LM3 2 4U1 A1+3-2V+4V-1 1LM3 2 4U4 A+-1 2 VV11 kR9d D2R1 11 0 k1+3-2V+4V-1 1LM3 2 4U3 A1 0 0 kR1 0sig n al_ou t p u tIR_in p u t _h ereContinuing WorkMore Simulations (that work)!IrDA compatibility circuitry.Interface to
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