CARS Cellular Automotive Remote System

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CARSCellular Automotive Remote System

• Abhishek Jain
• Mike Charogoff
• Matt Lasek
• Nguyen Le
• Blair Harness

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Objective

• Effectively work in a group to produce a working
  prototype of a cellular automotive remote
  system.
• At expo the demonstration system will send and
  receive information via a cellular phone.

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Functionality

• Resembles OnStar
• More universal, many more and different
  convenience features.
• Through CARS the user can control
• Starter
• Security system
• Heat and cooling system

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Functionality

• CARS obtains and sends information about
• Temperature
• Theft
• Vehicle location
• Accidents

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Optional Features

• User obtains information via voice messages
• Control movement of vehicle (prototype)
• Gives information of vehicle distance from user
• Information received from car on a terminal
• PC or microcontroller

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C.A.R.S.- System Overview
Vehicle
Home
Speaker, Microphone, and Solenoids
Cellular Phone
Home or Cellular Phone
Speaker, Microphone, and Solenoids
Wireless
Audio Amp
Audio Amp
Solenoid Driver, DAC and Audio Amp
Solenoid Driver, DAC and Audio Amp
Alternate implementation does Not require
solenoids, DAC, Or Speaker on Home system.
Misc. Digital Outputs Heater, Door L/U, etc.
MCU (W/ ADC on-board)
MCU (W/ ADC on-board)
Memory (RAM or Serial EEPROM)
Misc.Analog Inputs (Temp., Accelerometer)
Memory (RAM or Serial EEPROM)
Misc. Digital Inputs (Bumper, Optical
Encoders, Door Switch, ..etc.
GPS
LCD or Serial link to PC
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Functionality OverviewVehicle-based system
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Functionality OverviewHome-based system
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Preliminary Board Layout
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Preliminary Board Layout(And Mechanical Design
of OPTIONAL Mobile Platform)
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Tone Reception and Decoding
Cellular Phone
Speaker, Microphone, and Solenoids

• Principle of Operation
• Audible tones generated by the phone are
  converted
• to an electrical signal by the microphone
  (transducer).
• This electrical signal is amplified and fed to an
  ADC.
• The digitized signal is decoded. The specific
  decoding method has yet to be established, but
  one possible method would involve calculating the
  number of samples between zero crossings (or peak
  values). This number (n) would be unique for
  tones of different frequencies if the sample rate
  is adequate (gt 30k/sec).
• After decoding, the Microcontroller executes the
  issued command (i.e. start vehicle, Lock doors,
  Unlock doors, etc.).

(2) (LM380?)
Audio Amp
(1)
Solenoid Driver, DAC and Audio Amp
MCU PIC? 68HC1X? (W/ ADC on-board)
(4)
(3)
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Tone Creation and Transmission
Cellular Phone
Speaker, Microphone, and Solenoids

• Principle of Operation (Very much the
  opposite of tone reception process)
• The phone number of the Home station is stored
  in the cell phone so that the auto-dial function
  may be used. Two Solenoids are positioned
  (variable to accommodate various models) to push
  the appropriate buttons (thus calling the base).
• The Vehicle-based system then waits for the Home
  station to transmit an initialization tone to be
  sure that it has picked-up. (Alternatively,
  Vehicle-based system waits for ringing to stop
  followed by a delay. This simplifies Home system,
  but may sacrifice reliability and features).
• Now the Vehicle-based system may transmit by
  converting its stored data into an analog signal
  (via a DAC).
• This analog signal is amplified (LM380/LM386?)
  and converted into sound by way of a small
  speaker (transducer).
• Design Considerations
• Frequency response of Microphone and speaker.
• Solenoid voltage/power requirement (12V?).
• How standard is auto-dial on current generation
  cell phones?
• (Audio) cross-talk between speaker and
  microphone.
• How to hang-up? Another solenoid?
• How much data may be stored on memory device of
  choice?

Audio Amp
(2)
Solenoid Driver, DAC and Audio Amp
(1)
(4)
(3)
MCU PIC? 68HC1X? (W/ ADC on-board)
Stored Data EEPROM? SRAM? FLASH?
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Solenoid Control
MCU

• Principle of Operation
• A digital signal is used to control the driver
  circuit.
• Driver circuit consists of discrete components or
  an IC. Current spikes and other large, inductive
  load concerns must be analyzed.
• Solenoid only needs to be energized for a
  fraction of a second in order to push the
  appropriate button. Overall power use should be
  relatively small.

(1)
(2)
Solenoid Driver (L294/295 ?)
(3)
Solenoid
Cell Phone
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Digital Inputs
To Rest of Block Diagram

• GPS
• Take existing GPS device to track route of car.
• Data consisting of longitude, latitude, and
  possibly distance or speed of car sent via a
  serial data link to the microprocessor.
• Door Indictor
• Notifies home if user forgets to lock car door.
• Implemented by a push-button switch, which will
  be pushed if the door is locked and released if
  it is unlocked.
• Bumper Switch (Optional)
• Use spring-loaded switch so that when
  demonstration car hits an object the switch will
  be pushed. This will cause the car to change
  directions and avoid being stuck in one spot.
• Optical Encoder (Optional)
• Device will measure certain aspects of
  demonstration car such operating speed, direction
  and will relay this information, in the form of
  digital pulses, to the microprocessor.
• Microprocessor will then use this data to control
  the cars motion.

MCU (W/ ADC on-board)
Optical Encoder (Optional)
GPS
Door Indicator
Bumper Switch (Optional)
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Analog Inputs
To Rest of Block Diagram

• Temperature Sensor
• A thermocouple or RTD (resistance temperature
  detector) will be used to obtain a temperature
  reading inside and/or outside car. The
  measurement data will be sent to the user when
  the user gives the appropriate command.
• Anti-Theft Device
• A vibration sensor, possibly piezoelectric, will
  be used to detect any disturbances to the car.
  If a disturbance is detected, the data will be
  sent to the microprocessor which will alert the
  user.
• Accident Alarm
• Consists of a combination of devices that
  notifies emergency personal if the car is in an
  accident and gives them information about the
  location and severity of the accident. This will
  be done by using GPS (previously mentioned),
  accelerometer, and voice recordings. The
  accelerometer will give information about the
  magnitude of the accident and from this data will
  determine the severity of the crash.

MCU
Temperature
Anti-Theft Device
Accident Alarm
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Digital Outputs
To Rest of Block Diagram

• Heater/Air Conditioner
• Device will allow the user to warm/cool the
  interior of the vehicle from home by use of cell
  phone
• Heater will be implemented by use of a lamp which
  will be activated by a switch (MOSFET, BJT).
• Air conditioner can be realized by using a fan
  which would also be initiated by a switch.
• LEDs
• The realization of the peripherals such as
  activating the door lock/unlock, starter,
  headlamps, and horns used as the vehicle locater
  will be demonstrated using an array of LEDs.
• Motor Control (Optional)
• This device allows control of the demonstration
  cars motion. It does this by sending data to
  the cars motor and wheels to control the cars
  speed and direction.
• Auto-Dial Control
• This device consists of a solenoid which pushes
  buttons on the cell phone so that it can transit
  data.

MCU
Motor Control (Optional)
Auto-Dial Control
Heater Air Conditioner
Door Unlock/Lock Lights
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Division of Labor

• Abhishek Jain-Digital Outputs
• Matt Lasek/Nguyen Le-Inputs (excluding audio
  features)
• Mike Charogoff Audio Input/Output
• Blair Harness-Programming, Micro-controller

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Risks and Contingency Plans

• Areas of risk
• Microprocessor
• Learning hardware/software use of micro
  controller
• Shouldnt be an issue, several group members are
  familiar with technology
• Button pusher
• Ability to push (and possibly hold for speed
  dial) buttons
• Number of buttons we will need to push
• Plan on using solenoids for pushing buttons
• Multiple fixed solenoids vs single solenoid on
  servo drive
• Audio quality needed for tone recognition
• Shouldnt be a problem
• Add filters/amplification if needed

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Risks and Contingency Plans

• Areas of risk
• Voice reply (optional)
• Strings of digits sent back requires base
  station module
• If possible, add voice reply
• Time vs quality considerations
• Number of messages needed
• Storage requirements
• Accident alert thresholds
• Should not report accident under hi-performance
  vehicle acceleration
• Will need thresholds
• Might have to setup differently for different cars

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Schedule
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Summary

• CARS convenience features include
• Remote start/idle system
• Heat/Cool the interior of your car
• Lock/Unlock your car doors
• Anti-Theft System
• Accident Alarm System
• Temperature Sensor
• GPS

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Questions?