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					   Michael Felix, EE
 Matthew Fortin, EE
   Vince Crosby, EE
Kennard Childs, CpE
   Ken Bednasz - Telit Wireless solutions
   Tom Dang – L-3 Communications ALST
   Nicholas Hargar - NASA
   Design and implement a system using global
    system for mobile technology to unlock and
    start an automobile.
   Design and implement a system using Radio
    Frequency Identification capable of unlocking
    a vehicle.
                             Kennard   Matthew   Michael    Vince
                              Childs    Fortin    Felix    Crosby
GSM Programming                ●         ●
Interface Functionality        ●
Touch Sensing                                      ●
Passive Keyless Entry Sys.                         ●         ●
Power Systems                                                ●
Remote Starter                           ●
   Concept
    ◦ Call into the GSM, type in a number that specifies a
      command, that can unlock the doors, unlock the
      trunk, and start the engine.
   Considerations
    ◦ Security
    ◦ Input currents and voltages
    ◦ Programming
   Telit
    ◦ Government Regulations
    ◦ Resources that they provide
   GE863-GPS Interface
    ◦ Functionality
       18 configurable I/O pins
       Integration capability of GPS
       Supports an extended temperature
        range
       Quad Frequency band
   Evaluation Kit
    ◦ Reliability
    ◦ User Friendly
    ◦ Additional Accessories
       Documentation
         Set up cd
         Quick Start Guide
       GSM and GPS antenna
       Wall transformer
   Widely available
    ◦ Encompasses 86% of wireless tech
   Ease of integration
   Operational Range
    ◦ Limited to carrier service range
   Spectral Flexibility
    ◦ 400 MHz to 1900 MHz
   GSM is made in such a way that the RF
    transmission is not continuous
   Uses Guassian Minimum Shift Keying
   GSM requires 3.4 – 4.2 V with a 3.8 V nominal
    voltage
   Different operational modes require different
    amounts of power
   7.3/3.4 mA power saving mode (depends on
    network configuration)
   24 mA during normal operation
   53 mA during GSM receiving mode
   135/254 mA GSM sending mode
   Battery capacity must be at least 500 mAh in
    order to withstand current peaks of about 2A
   What is a practical solution?
    ◦ We will use a Lithium Ion Rechargeable Battery cell
      3.7 V per GSM module requirements
   Lithium Ion Battery is “sensitive” to charging
   They become unstable if overcharged and the
    cell can heat up
   May vent with flame
   Will use the LT1734 Lithium-Ion Linear
    Battery Recharger Controller
   Based on 5 V input
   PNP BJT collector carries
   300 mA to Lithium Ion Battery
   Depending on battery, charge specs may vary

                           Vcc              Isense
       5Vdc           C2
                      1u                             FMMT549/SOT
                           GND    LT 1734   DRIVE
                                                     Q1

                           PROG             BAT


              0
                                                                   Lithium
                      R1                                 C3
                      5k                                 10u        Ion
                                                                   Battery

                  0                                  0         0
   Tap into readily available sources
   Will use 12 V lighter adapter to charge
    Lithium Ion Battery
   Linear Regulator versus Switching Regulator
   Because of the large voltage drop, we will use
    a switching regulator circuit
   A linear regulator would require a sink to
    manage the wasted heat
   LM7805 Switching Regulator
                                   Q1                             L2
                              PNP BCE



                                                            D2
               V1
       12Vdc            C1
                        10u
                               R2                R3
                               4.7               4700
                                                        0 U1
                                        D1
                                                             LM7805C
               0    0                                   1                    2




                                                                   GND
                                                             IN        OUT




                                                                  3
                                                        C2                           C3
                                                        0.33u                        2000n


                                                                                 0

                                                 R4
                                                 0.5



                                             0
   Input/outputs
       GE863-GPS

       Antennas (2)

       USB Port

       SIM Card

       60 Male Pins (above)
             connect to the automobile
        80 Female Pins (below)
             connect to EVK2
Pins usage – (9)
Starter (5)
 - 2 pin outputs
 - 3 pin inputs
Doors Locks 1 output pin
Trunk 1 output pin
Power 1 input pin
Ground 1 pin

Pins Voltage and
Currents
Ports output 1mA @ 2.8V
Ports input 1µA @ 3.8V

Communication
GSM Antenna
T-Mobile SIM card
 Purpose: to program the GSM Module
    Connects the module to the Interface
    Connects to the computer via RS232/USB
We are able to load code using HyperTerminal through a virtual port.
While we have this setup we are also able to:
         Make calls from and into the GSM
         Run AT commands
 The HyperTerminal is an application that uses ATTENTION commands.



Examples:
AT+CPIN?
 -Query’s the SIM status

AT+CREG?
-Query’s the Networks status
Telit provided us with a custom version
of Python for Windows

PythonWin
 Compiler
 High level Scripting language

Storage Capabilities
 3MB of memory allocated for scripting
 1.5MB allocated for the Python engine
   Design Considerations:
    ◦ Modify pre-built (too easy)
    ◦ Interface with vehicle’s internal computer (too
      hard)
    ◦ Research, design and build our own module (just
      right)
                                    6”w X 6”d X 2”h
                                     3 input, 2 output
                            1
                           2
                           3
                             4
                                 
    GSM MCU

                                     ◦    Can use more for
                                          added features
BRAKE
CHECK
              TACHOMETER            Ignition Key
                                     positions
        “KEY-IN”
         CHECK                       1.   Off
                                     2.   Accessory
                                     3.   Run
                                     4.   Start
Steps for Proper Startup
                            1
                        2
                        3                    1) GSM receives signal
                                                to start
                            4



                                             2) Confirms password
GSM MCU
                                             3) Starter Relay to high
                                                (~2.8V to relay)
                                ALWAYS HOT
                                             4) Waits in loop for
                                                tachometer
TACHOMETER
                                             5) Starter Relay to low

             IGNITION
               COILS
Steps (continued)
                                                      6) Run Relay to high
                                                         (~2.8V to relay)
                                     1
                                 2
                                 3

                                                      7) Waits in loop for 20
                                     4



                                                         minutes
   GSM MCU                                            8) Pings both brake
                                                         check and “key-in”


                                         ALWAYS HOT
                                                         check inputs
                                                      9) Run Relay to low if
BRAKE   “KEY-IN”
CHECK    CHECK


                                                         either checks are
                    Electrical
                                                         high or time expires
                   Components
   Components:
    ◦   LM2907N-8 Frequency to voltage converter
    ◦   3 D1N4148 Diodes
    ◦   1 LED
    ◦   1 2N2222A transistor
    ◦   Assorted resistors and capacitors
    ◦   Voltage Regulator
                                                    VOLTAGE
                                                               GSM MCU
                                                   REGULATOR




    INDUCTIVE
      PICKUP
    ON SPARK
      PLUGS




   Frequency to voltage:           Voltage Regulator:
    ◦ 1000RPMs – LED off             ◦ Still needs design
    ◦ 2000RPMs – LED dim             ◦ Vmin = 3.4V
    ◦ 3000RPMs – LED fully lit       ◦ Vnominal = 3.8V
                                     ◦ Vmax = 4.2V
   Current Choice:            Other options:
    ◦ Design our own            ◦ Magnetic Pickup
      Need more research         Placed near a gear
                                  Pulses when gear cogs
    ◦ Modify a purchased           pass
      unit                        Can use same circuit as
                                   the inductive pickup
                                ◦ Interface with
                                  vehicle’s tachometer
                                  Easier but takes a lot
                                   less design
                                     D1           R4
                                                                        GSM MCU
                                   1N4148        1.5MOhm_5%
                             R1
                            1.5kOhm_5%
                                                              D3
                            LED1
                                                              1N4730A




                                         BRAKE
                                         LAMP
              BRAKE FLUID
               PRESSURE
        12V     SENSOR




   MCU input ~3.8V                                   Components:
   Brake Lamp input = 12V                              o 2 Resistors and 1 LED
   Brake System:                                       o 1 1N4148 Diode
    ◦ Brake Lamp turns on when                          o 1 1N4730A Zener
      brake fluid pressure
      increases
   Options:
    ◦   Positional Sensor
    ◦   Pressure Sensor
    ◦   Push-button
    ◦   Accepting Ideas…
   Objectives
    ◦ To design a radio frequency identification receiver
      capable of reading 13.56 MHz tag
    ◦ To create robust design suitable for application
      within a vehicle
    ◦ To implement capacitive touch sensors into system
      to activate receiver
               User



        Sense Electrode                              Envelope
                                            Detectors/Filters/Amplifiers
                                                   /Comparator



 Capacitive
Touch Sensor                                                                   Antenna
                                                                                         Tag
                                                                                Coils




                                             Power                 RF Tuning
                      Microcontroller
                                            Amplifier               Circuit




                  Keyless Entry Module
                 (Located within vehicle)
   Operating Temperature
    ◦ 0°C – 70°C
   Reader Signal Range
    ◦ 2 feet
   Enclosure
    ◦ 1’ X 1’ X .25’
   Power Consumption (Low)
    ◦ Not to exceed 50 mA during operation
   Robust
    ◦ Reduce the effects of ESD and other transients
   Overall Operation Time
    ◦ 800 ms
   Capacitive Touch Sensor
   Microcontroller
   Power
   Reader Antenna
   Filters
   RFID Tag (Transponder)
   Capacitive Touch Sensor
    ◦   8 Pin DIP
    ◦   Single Channel Sensor
    ◦   Response Time – 130 ms
    ◦   Drift Compensation
    ◦   Low power consumption – 20μA @ 3V
    ◦   Operating Temperature – 0°C – 70°C
   The QTouch device will continually charge a
    sense electrode surface
   The charge is then transferred to a
    measurement circuit
   After a few charge/transfer cycles within the
    chip, it can determine capacitance
   Once a finger is placed on the electrode
    surface, an external capacitance in introduced
    and thus affects the flow of charge
   The device then recognizes this change in
    charge and registers it as a “touch”
   RFID reader is activated by signal from touch sensor
   Reader will then being propagating a 13.56 MHz RF
    carrier signal
   Rectified carrier signal becomes power source for
    RFID tag, and tag is energized
   The tag will then send back an Amplitude Modulated
    signal to the RFID receiver circuit
   The Envelop Detector circuit recognizes changes in
    voltage amplitude and passes it through the RC filter.
   The shaped data signal is then fed into the
    microcontroller for processing
   The microcontroller then sends a signal to the
    Vehicle’s keyless entry module, which then unlocks
    the doors
   Overall flow of RFID software
    ◦ Microcontroller will remain in a Sleep mode
      Continuous software loop to put microcontroller in low
       power state.
    ◦ Interrupt will come from the QTouch sensor
      circuitry that will bring MCU out of sleep mode
    ◦ It will then initiate the software needed to begin
      propagating the signal from the antenna circuit
    ◦ Remaining software design focuses on data
      processing
   MicroChip PIC16C558 Microcontroller
    ◦   13 I/O Pinouts
    ◦   3 Interrupt Sources
    ◦   Voltage Range – 2.5 – 5.5V
    ◦   Clock Input – 20 MHz
    ◦   EPROM Program memory – 2 Kbytes
    ◦   Advantages
         Easy to program
         Using C Language
         Development Kit will assist with evaluating MCU
   Design
    ◦ Series LC Resonant Circuit
    ◦ Coil of wire is tuned to resonate at carrier frequency
                              b - thickness
               1                                    N - turns
      fo 
             2 LC
                     2                               a - radius
          .31(aN )
     L
        6a  9h  10 b


                                                         h - height
   Distribution of Power
    ◦ We will be using a series of voltage regulators to
      acquire the various voltages that we need
    ◦ 12 V Source – Direct to 12V Battery
    ◦ 5 V Source – LM78L05M
    ◦ 9 V Source – LM78L09M
   Amplitude Shift Keying
    ◦ The various bits are recognized through a variation
      in amplitude of the carrier signal
   Manchester Bi-phase Encoding
    ◦ The pattern of bits “1 1 0 1 0" encodes to
        “10 10 01 10 01"
                   Item     Expenses to   Projected
                               Date        Budget
Telit GSM/GPS Module         $295.98      $295.98
Telit EVK2 Evaluation Kit    $299.99      $299.99
SIM Card                      $10.00       $10.00
Microcontroller               $8.99        $8.99
Touch Sensor                  $9.99        $9.99
Relays                          $0         $34.84
Batteries                       $0         $49.95
Misc Components               $48.75       $53.25
Breadboard                    $29.98       $29.98
Soldering Kit                 $12.95       $12.95
Informational Materials       $29.95       $29.95
Total                        $788.84      $826.27
   Interface Complications
    ◦ Running single commands
      Command Prompt
      HyperTerminal
    ◦ Coding
      Gained insight into scripting in Python
    ◦ Connecting to a computer
      USB
      Serial Port
    ◦ Register GSM onto the network
   Starter Complications
    ◦ Mounting
    ◦ Ignition position
   PCB
    ◦ Not certified
   RFID complications
    ◦ Automobile interfacing
    ◦ Antenna Design
   Allocate more time towards circuit building
   Finish collecting data from vehicle
   Complete coding

				
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posted:8/17/2011
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