All you need to do is read temperature you may think about just using an
A/D converter and a temperature chip, can't think of any temperature
chips off the top of my head but you can look for them in Analog Devices
or National Semiconductor.  I think the Analog Devices LT1019, which is
a voltage reference has a temperature pin on it.  The I2C bus is just a
means of communication so if you're not putting any other devices on the
bus you could very well read the temperature through an A/D.  There are
PIC's with build on A/D, although they do cost more.

If you do want to stay with the I2C you will probably have to bit bang
your SDA and SCL lines.
There are a couple of App notes you can look at and the section on I2C
in the PIC data book should be enough to get you started.

Later
Dw

        -----Original Message-----
        From:   Craig Webb [SMTP:lucid@MAGNET.CA]
        Sent:   Thursday, May 14, 1998 2:22 PM
        To:     PICLIST@MITVMA.MIT.EDU
        Subject:        Re: I2C Interfacing (was I2C/LM75/16F84
Interfacing)

        check out scenix' appnote on I2C:

        http://www.scenix.com/app_note/index.htm

        At 12:53 PM 5/14/98 -0400, you wrote:
        >> I am working on a greenhouse temperature controller where a
16F84 is
        >> to communicate with a National temperature sensor LM75 over
the i2c
        >> protocol.  After reading all the data sheets on the LM75, I
find it
        >> difficult to begin.
        >>
        >> Is there an easy way out? If I am only reading the
temperature values
        >> and not using all the features that i2c can do.  There is
nothing much
        >> I can find in national and Philips web sites that is useful.
        >
        >I sure would like to see a little tutorial on I2C.  Anybody out
there
        >want to show us what they learned on?
        >
        >Thanks,
        >
        >- dan
        >
        >