April,

what about using second crystal TIMER1 to replace DS1307
TMR1 can run when the pic is in sleep and use one of pic's I/O
as one wire interface all you need is EEPROM.

hope this helps.
Andre Abelian






April Junkbox wrote:

> I am working on a hobby application involving a PIC 18F6621 c/w I2C 
> master, and 3 slave devices. The slaves are:
>    DS1307 Real Time Clock
>    DS2482 One Wire Interface
>    24LC512 EEPROM
> I have the early prototype working with brute-force delays (i.e. spin 
> the CPU until the status bit is ready). I have found numerous 
> samples/examples for I2C masters and each slave device, but nothing 
> applicable to multiple slave devices.
>
> Here is my tentative plan:
>    a) write an interrupt service routine for the I2C interface
>    b) in the Main loop, write an I2C service which dequeues requests 
> and queues results
>    c) also in the Main loop, write 3 (pseudo) tasks which queue 
> requests and dequeue results
>
> All the usual questions:
>    Does this strategy make sense?
>    Is there a better way?
>    Who has samples/examples?
>    What would you do differently?
>    etc.
>
> ... and thanks in advance for your input!
> Jake
>
>

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