Changing I2C address of DS1307 RTC

Hello to the Arduino community!

I have 2 DS1307 RTCs and i want to connect them to the same I2C bus.

I have read the datasheet of DS1307 but i can not find something that states how to change the default address.

Is it possible to change the default address of DS1307? So i can program each of them with a different time (kind of World Time project).

Thank you :)

I see no indication of being able to change the address.

Why not use a single DS1307 and simply calculate the difference is software? If you only care about time of day it's a simple operation.


I agree. Also be aware that man with one watch always knows the time, man with two watches never really sure. ;)


Hey guys

Thanks for you replies.

Never though it that way! I will try the software approach.

And yes, imagine what a confusion would be when having multiple watches showing different times :D

Watch out for the tricky quarter and half hour zones!

Make me think of the Three Stooges routine when Moe asks Curly for the time? Curly pulls up his sleeve to reveal three watches and asks Moe: "What's with the three watches?" Curly replies: "That's how I tell time. See, the one on this end is three hours fast every other day. The one on the other end is two hours slow each Thursday. The one in the middle is broken and stopped at 3 o'clock" "So," says Moe, "What time is it?" Curly reaches into his pocket, pulls out a pocket watch, and says: "Four-thirty."