I have a DS1307 RTC chip that I want to interface with multiple masters. One, an ATMega chip, will only ever really need to pull time data from the chip and the other (probably just an ATTiny) will be there solely for the purpose of receiving wireless time updates and updating the time on the RTC. I realize that I could just build in this wireless update functionality to the ATMega chip, but I'm trying to work on a modular RTC board that, as far as the ATMega is concerned, is exactly the same as any other similar RTC like the DS1307 or the DS3231 (Chronodot).
Question is, can I just wire it all to the same two i2c bus lines and communicate with the RTC from BOTH chips? If so, do I need to do anything to ensure that both are not trying at the same time? I assume that, since i2c already supports multiple slave devices that this should generally be handled for me. But, in general, should this work. I'm ok with the ATMega trying to get the time and having to wait if the RTC is being updated. Which would be rare anyways, maybe every hour at most.