> -----Original Message-----
> From: pic microcontroller discussion list
> [mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Charles Laforge
> Sent: Saturday, January 10, 1998 15:04
> To: PICLIST@MITVMA.MIT.EDU
> Subject: MORE... I2C protocol
>
>
> Hi
>
> First I have to thank everyone who gave me info and pointers on this. I
> have alot of reading to do now.  I have a few more questions first.
>
> Are the I/O pins on the 16C84 (or other Pics without built in I2C)
> compatible with I2C directly (with pull ups) or do I need to attach some
> piece of hardware in between the pins and I2C lines?

        No, the pins will work fine. If you are using the PIC as a lone master,
or
if you are using it as only a slave, than almost every PIC outthere would
work through bit banging. However, in a multimaster environment you would
need an open drain output, something the 16C84 does have, so it should work
for almost any situation. About the only thing you might need are pullups on
the data line, depending how you do it.

> What are the advantages of using a Pic which has I2C capabilities built
> into it?  Do they contain instructions for I2C protocol?  Is it a
> hardware thing?

        Warning, the I2C hardware on the PICs that have it only does slave mode,
for master you will have to bit bang. Aside from that, if you are looking
for a PIC to be a slave, many people recommend using a PIC with the
hardware, it is just simpler. TTYL