1. Project Forget-Me-Not
TCSP2 - Design Constraints
ECE477 Group 4
Chris Cadwallader
Craig Pilcher
Andy sydelko
Mike williams

2. Updated PSSCs
An ability to determine the operating state of the vehicle via the OBD-II port.
An ability to determine the presence of a child in a safety seat.
An ability to use multiple safety seats in one vehicle.
An ability to sound an audible alarm when the ignition is turned off.
An ability to interface directly to the internal vehicle CAN.

3. Block Diagrams

4. Block Diagrams

5. Important Design Constraints
On-chip peripherals
CAN, PWM for audio output
On-chip memory
Flash for audio samples
Power consumption
Child-side is battery powered
Cost
Off-chip peripherals
RF Tx/Rx, 433 MHz

6. Microcontroller – 9S12DP512C
Advantages
Multiple OBD-II protocols supported
CAN, SWCAN, Keyword 2000, J1850
PWM, A/D for older protocols
Built-in software libraries (Code Warrior)
512K Flash
2 SCI ports (debugging and RF decoder)
Extra input pins for future expansion
8 inputs = 256 possible status messages
Disadvantages
Audio – Want to be loud enough to hear easily
LM386 Audio Amplifier

7. Wireless Interface RF RFID Adequate range Low power consumption
Low cost
Linx XCVR
Tx and Rx units easily paired
No micro needed on Tx side – lowers power cost
RFID
Passive transmitters – low range
Active transmitters – disposed after use
Prohibitively expensive