> I need a bunch (max 6) 16f877 pic's to be able to talk to each other.
From
> the literature on the Microchip site I gather I can use SSP with
SPI(Master
> Mode) and I2C(Master/Slave).  Is this the only(best) way to have my pic's
> talk?

Of course not.  You can invent an infinite number of schemes.

> What are the benefits of SPI to I2C?

SPI can go faster because each line is actively driven in both directions,
and two bits (one in each direction) are transferred each clock cycle.  On
the other hand, it requires three bus wires instead of two, and usually a
separate "chip select" line per slave device.

IIC specifies a bit more protocol than just pumping bits between master and
slave.  It is therefore more flexible, and the PIC implementation allows for
flow control in one direction at least.

I would use IIC unless you are trying to go off board or the transfer rate
isn't fast enough.  Due to a bug in the PIC implementation, you need to put
a capacitor on the SDA, and I personally won't use it above 500Kbits/second.


********************************************************************
Olin Lathrop, embedded systems consultant in Littleton Massachusetts
(978) 742-9014, olin@embedinc.com, http://www.embedinc.com

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads