Hi Picpros,

I'm using the PIC16f84 in an automotive application. Basically, its an alarm
and an anti-theft device. The alarm monitors the doors, trunk and the hood
of the vehicle when the ignition is turned off. Whereas, the antitheft
device monitors it continually.

The most significant feature of this project is a bypass that gives the user
the option of setting a bypass word. This word is used for two things;

1. To reset the system in the event the vehicle was tampered with.

2. To impliment a bypass of the system in the event that the vehicle must be
sent    to the mechanic.


My problem is that the contents of the registers which contain the bypass
word is lost whenever the vehicle's battery power is removed then replaced.
Obviously, this would defeat the purpose of the system.

As I see it, the way out of this to have a back-up battery on board, or on
the other hand to use some form of memory device. However don't have the
knowledge in none of the above. I'm therefore asking your assistance.

Thanks in advance.

Rawle
Bye,
Rawle.