Jonathan Baker <PICLIST@MITVMA.MIT.EDU> wrote:

> Im working on a network using PICS.
>
> All nodes on the network are identical, all joining onto a single
> bus - ie each pic doesnt receive and the re-transmit the data.
>
> (each pic is also programmed identicaly - including ID bits)
>
> Can anyone think of a way to get each PIC to allocate itself a
> unique number

Jonathan:

Someone -- I forget who -- already suggested a method that involved
random-number generation, and I'm sure that others will post similar
methods that are a little simpler.

If you use one of those methods, remember that absent any difference
between the PICs, each PIC will generate the same random numbers,
thereby preventing the ID-allocation method from working.

So... You need some differences between the PICs.  The easiest way is
to put a low-accuracy RC on each PIC's MCLR line or -- if the PICs
don't need to have accurate timing for anything else they're doing --
to clock the PICs with RC oscillators rather than crystals or ceramic
resonators.

-Andy

=== Andrew Warren - fastfwd@ix.netcom.com
=== Fast Forward Engineering - Vista, California
=== http://www.geocities.com/SiliconValley/2499