Hi!

I have already did this. The PIC is in sleep mode when it is waiting for the

key press so consumption is reduced to minimum.
For changing the key code you have to enter the code: "1234" then the your
old valid code "XXXX" end then your new code "YYYY" and repeat the new one
ones again "YYYY".

If you want to unlock (the door for ex.) just enter the valid key code end
press "#".( # is as enter, * is as clear whole number) . If the code is NOT
correct, you can try once more and if the code is NOT correct the second
time, you can try again. But, if the third time the code is not correct the
pic will disable keypad for three minutes. After that, it will give you two
chances to enter the right code. If the second time (in global it is the
fifth)
is not correct the pic will disable keypad for cca THREE HOURS. After
that you can enter just ones. If this time the code is NOT correct, the pic
will disable the keypad for cca THREE DAYS.
Interesting thing is something else.

For example:

You have entered (in global) five times the code and it wasn't correct. You
now have disabled keypad for THREE HOURS. After TWO HOURS you decided to
switch the power off to reset the pic and this three hours period. You CAN
NOT. When the power will come back, it will start to count down WHOLE THREE
HOURS period again. So in total will be five hours period.

During those periods NO ONE can reset it. This may be a bug (may be not)
take it as you want.

Valter

Chris Camerlin wrote:

> I'm working a keyless entry system using the PIC16C84 and would
> appreciate anyone's tips and or advice.  I plan for the system to run on
> a 4x3 keypad outside and it will unlock or lock the door on a house when
> the proper code is entered.
> Thanks.
> chris camerlin

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Content-Disposition: inline;
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