>>Your right the SDA and SCL line are supposed to pull up, the
>>address lines are used to cascade up to four devices and arent
>>required for this particular project.
>
>Whether they're required or not for your application, they should't be
>left floating. They should either be:
>
>1) all pulled down to ground and use address 0 or
>
>2) all pulled up and use an address of all 1's.
>
>Either way will work but open inputs are generally a bad practice that
>will sometimes create strange problems.

Many of these devices seem to have internal weak pull-downs in them, biasing
the pins so that the device will appear at the base address as though the
pins are wired to 0. You then need only to pull up the address pins
required. I have done exactly this with Atmel AT24C36/64 devices. They
specifically state to leave the address pins open circuit when a low state
is required on that pin, so it is not necessarily bad practice for these
devices.

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