I.K.E. Infrared Keyless Entry

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I.K.E. Infrared Keyless Entry
EE 4512 Senior Design
Department of Electrical and Computer
Engineering April 24, 2001 Design Review
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Team Members

• Kenny Reynolds Team Leader Dr. Ray Winton -
  Advisor
• Adria D. Jones Ray Smith

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Design Task Breakdown

• Kenny Reynolds
• Digital Signal Encoding / Decoding
• Microcontroller Interface
• Adria Jones
• Transmitter / Receiver Amplification
  Transmission
• Ray Smith
• IrDA Implementation

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Problem Statement

• Radio Frequency Keyless Entry (RFKE) does not
  provide flexible interaction between automobiles
  and external communication devices.
• Solution
• Infrared 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.

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Key Components

Handheld Ir Signal Transmitter
Optical Signal Receiver
Amplification
Decode


Micro- Controller
Specified Function
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Block Diagram
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Objectives

• 1. Functionality
• The receiver unit will be able to lock and unlock
  doors on properly equipped vehicles. For proper
  signal detection, a series of infrared diode
  receivers to receive the incoming infrared
  signal.
• 2. Unique Signal Keying
• Necessary to ensure vehicle security is not
  compromised.
• This will be obtained by encrypting the
  transmission signal and decrypting the signal at
  the receiver unit.
• The receiver must acknowledge IR signaling from
  devices operating at IrDA v1.1 protocol to
  receive to allow communication from third-party
  devices.

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Objectives

• 3. Effective Range
• Handheld transmitter Conventional infrared
  signaling must be able to be operated at a
  minimum of 20 feet under normal sunlight
  conditions.
• IrDA device Due to limitations with IrDA
  transceiving, communication with third party
  devices will be limited to two meters.
• IR receiver Must be able to receive proper
  signals from outside the vehicle (glass
  refraction, window tinting, etc.).

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Objectives

• 4. Power
• Power to the receiver will be provided by the
  automobiles 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.
• The transmitter battery will last 2 years with
  typical usage.

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Objectives

• 5. Packaging
• IR receiver LED Packaged dimensions will not
  exceed 1" by 1" by ½". The receiver LED will be
  placed within sight from the outside of the
  vehicle.
• IR receiver logic capabilities will be packaged
  in a box no larger than 5" by 5" by 2".
• Transmitter unit Package dimensions will be no
  larger than 2" by 3" by 0.75". It will be formed
  in a shape conducive to pointing.
• 6. Durability
• Transmitter will be shock resistant.
• Receiver must be rugged enough to withstand
  vehicle mobility.

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Objectives

• 7. Cost
• The total component cost of the system will not
  exceed 35.

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Transmitter
HT-680 Encoder
PIC16F84
Transmitter Circuitry
LED
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Serial Encoding / Decoding ICs
Holtek HT-680 serial encoder and HT-692
decoder. Provide 8 data address lines and 4
control lines. (High, Low, Open) Built-in RC
Oscillator allows for multiple
transmission frequencies (0.15 kHz to 2.6
kHz).
HT-680 Serial Encoder 4 Data Address Lines 8
Address Lines
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Serial Encoding

• 8 control lines, 4 data lines
• Can be tied High, Low, or left open.
• 312 531,000 possible serial combinations.
• Example Coding from PIC (f 100 kHz)
• A0 A1 A2 A3 A4 A5 A6 A7 A8 D1 D2 D3 D4
• 0 1 0 1 1 0 1 0 0 1 1
  1 0

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Signal Transmitter Circuit
IR LED's
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Signal Transmitter Circuit
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Receiver
HT-692 Decoder
PIC16F84
Interface to Vehicle Wiring Harness
Receiver Circuitry
IrDA Endec
IrDA Transceiver
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Signal Receiver Circuit
IR Sensor
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IrDA Signaling
3/16 RZI-IR
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IrDA Reception

• We plan to use a IrDA transceiver and
  encoder/decoder pair linked to the PIC
  microcontroller.
• Only reception is necessary.

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Conclusions / Continuing Work

• Signal coding is necessary to ensure proper
  security.
• Infrared provides a reliable medium to pass
  information.
• Next
• Develop means of easy code setting.
• Develop secure IrDA device encryption coding to
  ensure security.
• Hardware Fabrication.