Not simpler and cheaper, but less power hungry.  I liked the idea of=
=20
using an RTC with alarm switching a FET or similar to power the PIC.=
=20
 The RTC can either have its own battery (internal, lasts several yea=
rs)=20
or connection to the regular batteries and draw very little power.

But there again (as was previously mentioned) your real drain, the on=
=20
time of the micro, is what you should really be concerned about...

-Adam

Gabriel Caffese wrote:

>Hi again,
>
>        I=B4ll give you more information about the project:
>
>        1) The whole system will be a 0=BAC for 4 days, and then 4 d=
ays at 25=BAC, and
>again....
>        2) I NEED to wake up the PIC, at exacly 300 seconds.
>        3) The system will store in an external EEPROM, the date and=
 time, every
>time
>the user pulses a switch.
>
>        So:
>        (a) I understand I have to use Timer1 with a 32,768khz crist=
al.
>        (b) I=B4ve succeeded in lowering the consumption up to 10ua.
>
>        Is (a) the best solution ??????
>        Do you know about another one, simpler, and cheaper ?
>
>        Thanks again,
>
>                                Gabriel.-
>
>-----Mensaje original-----
>De: pic microcontroller discussion list
>[mailto:PICLIST@MITVMA.MIT.EDU]En nombre de Morgan Olsson
>Enviado el: Viernes, 21 de Junio de 2002 06:51
>Para: PICLIST@MITVMA.MIT.EDU
>Asunto: Re: [PIC]: Turning on a PIC micro every 5 minutes.....
>
>
>In sleep, power the PIC by voltage from the lower cell only trrough =
a diode.
>Low voltage=3Dmuch lower current.
>
>Then when the PIC wakes up it uses two transistors to connect it=
=B4s supply to
>the top cell plus.
>
>If you can arrange to run on the 32kHz xtal all times except the rar=
e
>occasion every month that would help much!
>
>/Morgan
>
>Hej Gabriel Caffese. Tack f=F6r ditt meddelande 04:43 2002-06-21 enl=
igt nedan:
> =20
>
>>       But I forgot to say, that the system will use 2 button cell
>>   =20
>>
>(lithium)
> =20
>
>>batteries in parallel,
>>so Vdd is 6volt, and will use a 4mhz Xtal, cause it has to download=
 data
>>every 1 month.
>>       Another thing, is that I have never been able to get a lower
>>   =20
>>
>consumption
> =20
>
>>that 0.08 ma @5v,
>>in sleep mode !!!
>>       So, what can I do ?
>>   =20
>>
>
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>
>
>
>
> =20
>

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