CARS Cellular Automotive Remote System Critical Design Review

1. CARSCellular Automotive Remote SystemCritical Design Review Matt Lasek Blair Harness Nguyen Le Abhishek Jain Mike Charogoff

2. C.A.R.S.- System Overview Home Phone Cellular 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

3. Board Layout Presented by Abhishek Jain

4. Board Layout: Bottom View and Door Detail Presented by Abhishek Jain

5. 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

6. Alternative Button Pusher Apparatus (Optional) • Uses two motors and one solenoid. • Is the most flexible, but also most complicated design. Presented by Abhishek Jain

7. 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

8. 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

9. Regulated Voltage Supply • This circuit has been tested and works properly. Presented by Mike Charogoff

10. 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

11. Heater/Lamp Circuit Presented by Mike Charogoff

12. 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 Microcontroller’s 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

13. Audio Input Circuit Presented by Mike Charogoff

14. Actual “Audio-In” Signal F = 800 Hz 1.0 V/Div. (Vertical) 500 us/Div (Horizontal) F = 2 kHz Presented by Mike Charogoff

15. 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

16. Voice Messaging Circuit Presented by Mike Charogoff

17. Microphone Subcircuit(Only used to record messages) Presented by Mike Charogoff

18. Preliminary Message List Presented by Mike Charogoff

19. 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

20. Accelerometer Schematic Presented by Matt Lasek

21. Drop from 1ft: Pulses Amplitude: 900mV Duration: 750us Sampling Freq: 666Hz Drop from 6in: Pulses Amplitude: 600mV Duration: 1ms Sampling Freq: 500Hz Test Results Conclusion: Microprocessor can detect pulses since it can sample up to 140kHz Presented by Matt Lasek

22. Temperature SensorLM34 • Used to detect car’s inside temperature • Power Supply: 5V - 30V • Temp Range: -50 – 300 • Accuracy: over temp range • Conversion Factor: 10.0mV/ Presented by Matt Lasek

23. Temp Sensor Schematic Presented by Matt Lasek

24. 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

25. 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

26. Microprocessor Presented by Blair Harness

27. Microprocessor – port use Presented by Blair Harness

28. 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 >50ms (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 >300ns between setting the address and enabling the chip. Presented by Blair Harness

29. 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

30. 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

31. Parts and Cost Presented by Nguyen Le

32. Parts and Cost continued 5 Engineers*25 dollars/hour*40 hours/week*15 weeks=$75,000 At $400/unit we need to sell 290 units before we start to show a profit Presented by Nguyen Le

33. 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

34. 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

35. Questions?