(Car Security System)

A final project for: ECE 551, Computer Systems Manufacturing Lab

Dept. of ECE, UMASS Amherst

Project Description

The final project consisted of two main parts. The programming of the PIC16C71, and a graphic emulator using a lab pc. The emulator was coded using C++, and some 8086 assembly for the mouse controls. The purpose of having an emulator was to be able to speak with the PIC demo board through the COM2 port, was to allow for a more interactive interface then was previously offered by using PROCOMM. By using the mouse, the emulator allows for selection of the signal values. A fully functioning car alarm would have pre-installed sensors to send the signals to the brain(PIC). These signal values would then be relayed to the PIC via the COM2 port on the lab pc. The PIC then compares these values to values that were initially programmed into the PIC. Depending on which values were imputed, there would be an output to the LEDs on the PIC board.

Design Process

The code for the PIC16C71 consists of a finite state machine. There are three states; 1. Disarm: within this state there is a BEEP function. This function does not allow the exiting of the state unless the signal received from the emulator is 4F in hex. 2. Armed: there are two ways of exiting this state, one is by receiving a 5X in hex (X=don't care), which exits back to the disarm state. Or by receiving [(4or3)!F] in hex, which exits to the Alarm Sounding Off(ASO) state. 3. ASO: there is only one way out of this state, and it is by receiving a 5F in hex, which exits to the disarm state. Tools used with design of the project: Mpasm, Mpsim, and PICstart software PIC demo board and PROCOMM C++ and 8086 assembly

Manufacturability

The Car Alarm, in today market, is on high demand day in, and day out. Therefore our design has a real marketable aspect to it. Our design is built on the use of a Microchip PIC16C71 as the brain of the unit. There a couple or reasons for choosing this certain pic for our unit. Taking into account that these units will be used in cars, were the temperature of operations varies greatly, we chose the 71 series chip that allows for a - 40deg C to 85deg C(16C71-04I/P-ND). The cost of this chip is also attractive, being only $5.86/per chip in quantity. This chip is of a OTP configuration. This chip will allow for future expansion at a minimal cost overhead. The support circuitry is hard to judge for cost and development, but a good estimation of our cost of the unit would be approximately $55.00 This includes the cost of the finished emulator. Time to market would be approximately, 3 months for 1000 units. Due to the high demand, there will always be a market for a car alarm.

Acknowledgements

Prof. Burleson
Abdul Kanaan : AKanaan@ecs.umass.edu (12/22/95) li Wu : LWu@ecs.umass.edu (12/22/95) Mark Krause: Krause@.umass.edu (12/22/95) burleson@ecs.umass.edu (Last Update: 12/18/95)