At 11:54 PM 6/20/02 -0300, Gabriel Caffese wrote:
>Hello everyone,
>
>         I have a project where I have to take GREAT care of battery life.
>         It=B4s a portable system with a 16F627, that has to make some=20
> measurements
>every
>          300 seconds, and stay on for 20 seconds.
>         Once the system is turned on, it will NEVER be turned off.
>         So, system=B4s life depends on batteries life. When batteries die,=
=20
> the whole
>system is disposed.

How accurate does the 300 seconds have to be?  If you can tolerate some=20
variation, I would consider using the watchdog timer.  You will have to=20
calibrate the watchdog on a periodic basis - this is easily done by setting=
=20
the watchdog to no pre-scaler, running the PIC, then timing how long it for=
=20
the watchdog to trigger.  Use that measured time as the basis for setting=20
how many watchdog timeouts you need to achieve 300 seconds.

dwayne

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Dwayne Reid   <dwayner@planet.eon.net>
Trinity Electronics Systems Ltd    Edmonton, AB, CANADA
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