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

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.

Block Diagrams

Block Diagrams

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

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

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