Download - Project Forget-Me-Not
TCSP2 - DESIGN CONSTRAINTS
ECE477 GROUP 4
CHRIS CADWALLADERCRAIG PILCHERANDY SYDELKOMIKE WILLIAMS
Project Forget-Me-Not
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
CostOff-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 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