CARS Cellular Automotive Remote System Critical Design Review

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CARSCellular Automotive Remote SystemCritical
Design Review

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

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C.A.R.S.- System Overview
Cellular Phone
Home Phone
Speaker, Microphone, and Solenoids
Voice Messaging Used to Obtain Data
Wireless
Audio PreAmp, Filter, and Amp
Solenoid Driver
Voice
Number Keys Used for Control
MCU (W/ ADC on-board)
Misc. Digital Outputs Heater, Door L/U, etc.
Temperature Sensor and Accelerometer
GPS
Misc. Digital Inputs
Presented by Abhishek Jain
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Board Layout
Presented by Abhishek Jain
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Board Layout Bottom View and Door Detail
Presented by Abhishek Jain
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Alternative Button Pusher Apparatus (Optional)

• Uses one motor and one solenoid.
• Is more flexible than stationary design, but
  more complicated as well.

• Principle of Operation
• A small DC motor goes though speed reduction
  gearing before turning a shaft.
• This shaft is attached to a slotted disk and a
  solenoid.
• The solenoid is constrained in all but one
  direction by the spiral slot which dictates the
  solenoids movement.
• An optical encoder is used to obtain movement
  data. This data is used to determine position.
  (Home switch not shown)

Presented by Abhishek Jain
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Alternative Button Pusher Apparatus (Optional)

• Uses two motors and one solenoid.
• Is the most flexible, but also most complicated
  design.

Presented by Abhishek Jain
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Solenoid Driver Circuit

• Design Features
• Optical Coupling (4N25) between large inductive
  load and MCU to minimize noise.
• Protective diode across load.

VA
Presented by Abhishek Jain
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Solenoid Driver Simulation and Measured Values
VLOAD
VA
During testing of the actual circuit the
following values were measured VLOAD 11.54
V VA 4.95 V Iin 300mA (Actual load is closer
to 40 Ohms)
Presented by Abhishek Jain
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Regulated Voltage Supply

• This circuit has been tested and works properly.

Presented by Mike Charogoff
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Basic Display Circuit

• A serial input (active low) controls the state
  of the parallel outputs.
• This circuit has been tested and works properly.
  It is used three times in the project.One of the
  three implementations will use discrete LEDs
  instead of the seven segment display shown.
• The 74LS164 chips will receive a decoupling
  capacitor (not shown).

Presented by Mike Charogoff
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Heater/Lamp Circuit
Presented by Mike Charogoff
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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, filtered,
  and fed to the Microcontrollers internal ADC.
• The digitized signal is decoded. The decoding
  method will most likely involve calculating the
  time or number of samples between peak values.
• After decoding, the Microcontroller executes the
  issued command (i.e. start vehicle, Lock doors,
  Unlock doors, etc.).

(2)
Audio Amp and Filter
(1)
Solenoid Driver
Voice
MCU 68HC12 (W/ ADC on-board)
(4)
(3)
Presented by Mike Charogoff
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Audio Input Circuit
Presented by Mike Charogoff
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Actual Audio-In Signal
F 800 Hz
1.0 V/Div. (Vertical) 500 us/Div (Horizontal)
F 2 kHz
Presented by Mike Charogoff
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Voice Messaging

• Principle of Operation
• Power Up MCU brings ISD25-120 Voice chip out of
  Power Down mode (by pulling PD pin low).
• Set Address An address corresponding to the
  message to be played is put on the address lines.
• Select Chip After meeting certain timing
  requirements (tset and tPUD), the chip is enabled
  (CE 0) thus playing the selected message.
• Wait for Message Completion The (active-low)
  End-Of-Message (EOM) pin is then polled for a
  logic low signal.
• Disable Chip The chip is then unselected (CE
  1) before the process is repeated.

Cellular Phone
Audio PreAmp, Filter, and Amp
Solenoid Driver
Voice
MCU (W/ ADC on-board)
Presented by Mike Charogoff
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Voice Messaging Circuit
Presented by Mike Charogoff
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Microphone Subcircuit(Only used to record
messages)
Presented by Mike Charogoff
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Preliminary Message List
Presented by Mike Charogoff
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AccelerometerACH-04-08-05

• Used for Car Alarm and Accident Alert Systems
• 3-Axis Detection X-axis, Y-axis, Z-axis
• Power Supply 5V
• Sensitivity Typical 1.80mV/g
• Temperature Variation .28 per
• Surface Mount Had to buy adapter

Presented by Matt Lasek
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Accelerometer Schematic
Presented by Matt Lasek
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Test Results

• Drop from 1ft
• Pulses
• Amplitude 900mV
• Duration 750us
• Sampling Freq 666Hz

• Drop from 6in
• Pulses
• Amplitude 600mV
• Duration 1ms
• Sampling Freq 500Hz

Conclusion Microprocessor can detect pulses
since it can sample up to 140kHz
Presented by Matt Lasek
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Temperature SensorLM34

• Used to detect cars inside temperature
• Power Supply 5V - 30V
• Temp Range -50 300
• Accuracy over temp range
• Conversion Factor 10.0mV/

Presented by Matt Lasek
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Temp Sensor Schematic
Presented by Matt Lasek
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Test Results

• Test to determine if Temp Sensor responded to
  heater (lamp)
• Recorded
• Room Temp 75.5
• Lamp heat 84.0 (with 5V supply)
• Conclusion Temp Sensor effectively detects heat
  given off by lamp.

Presented by Matt Lasek
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Microprocessor

• Using a 9S12BADGE development board.
• Utilizes a Motorola MC9S12DP256B 16-bit processor
  (112 pin LQFP ).
• Features
• 256K Flash, 12K Ram, 4K EEPROM
• 2 8 channel (10 bit) ADC
• 89 digital I/O channels, 20 with interrupt/wakeup
• 2 SCI, 3 SPI, 8 channel timer

Presented by Blair Harness
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Microprocessor
Presented by Blair Harness
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Microprocessor port use
Presented by Blair Harness
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Microprocessor - software

• Void Update_Display(int display_A, int display_B,
  int display_C)
• This would just update the displays with the
  bytes provided. We would use a single "clock"
  for all three displays (that's why we might do
  them all in a single function).
• Void Load_MSG(int MSG_NUM)
• This is actually alot like the above function,
  since it mainly modifies a shift register. It
  would need to check that the PD pin on the voice
  chip is low first (and make it low, then wait for
  gt50ms (if not already low)).
• Void Play_MSG(Void)
• This would set CE_BAR low on the voice chip
  (selecting it). The message would play. The
  EOM_BAR pin would be polled during this time
  looking for a logic (which indicates an
  End_Of_Message). Then the CE_BAR could be set
  high (deselecting the chip). Note We need
  gt300ns between setting the address and enabling
  the chip.

Presented by Blair Harness
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Microprocessor - software

• INT GET_TEMP()
• Reads ADC channel of temp sensor.
• ____ GET_POSITION()
• Return/store the data obtained from the GPS.
  Return data format unknown.
• Void DIAL(int SOLENOID_NUMBER, int
  TIME_DURATION)
• Energizes selected solenoid for TIME_DURATION
  milliseconds.
• Void main()
• Monitor audio and accelerometer input, in some
  form of loop. If either is detected, process,
  and call appropriate function.

Presented by Blair Harness
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GPS Module

• Decision TBD on GPS module
• Laipac's 12-channel"ALL-in-View" TF10 GPS module
  
• Tri-M REB 12R7 12 channel GPS module

Presented by Nguyen Le
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Parts and Cost
Description Part Number Price Quantity Total Cost
Motorola Processor (in use) 68HC12 Donated 1 0.00
Processor PIC 16F87 3.00 1 3.00
Memory Voice Rec/Play IC ISD25120P 9.58 1 9.58
3 Axis Accelerometer MSP1004 25.00 1 25.00
Temp Sensor IC LM34DZ 2.33 1 2.33
Low Power Audio Amp IC LM386M-1 0.58 1 0.58
OMNI Microphone 359-1011 1.09 1 1.09
Incand Lamp CM7219 0.49 2 0.98
Capacitors 1uF 399-2155 0.12 15 1.82
Volt Reg. Fix Pos IC 296-12396-1 0.75 3 2.25
NPN Transistors 2N3904 0.17 30 5.14
Serial In/Parallel Out Register IC DM74LS164N 0.72 4 2.88
Presented by Nguyen Le
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Parts and Cost continued
Description Part Number Price Quantity Total Cost
Solenoids SOL-52 2.00 4 8.00
GPS TBD 80.00 1 80.00
Cell Phone Donated
LEDs Donated
Bumper Switch Donated
Door Switch Donated
Perf Board Donated
Fan Donated
Tentative Total Cost 144.97
5 Engineers25 dollars/hour40 hours/week15
weeks75,000
At 400/unit we need to sell 290 units before we
start to show a profit
Presented by Nguyen Le
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Division of Labor

• Abhishek Jain Solenoid mounts and driver circuit
• Matt Lasek Accelerometer and temperature sensor
  interfacing
• Nguyen Le GPS data control and interfacing
• Mike Charogoff Audio Tone Reception and Decoding
• Blair Harness Microcontroller Programming

Presented by Nguyen Le
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Schedule
Milestone 1 Hardware is to be built with partial
software interface completed with partial
testing in progress
Milestone 2 Hardware and software to be
interfaced, continue testing and debugging.
Presented by Nguyen Le
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Questions?