ESP8266 Community Forum

Now I got it!
So I've been trying to write to DS1307 memory till now...
Is this why I failed to set my clock while writing to that memory?!
I need to know my eeprom address. Could you please tell me how to find it?
This is my module:
https://www.banggood.com/Tiny-RTC-I2C-A ... 90137.html
Is there any difference between ports on each side? and if there is, Which side is for eeprom?
I really appreciate your help. Thanks.

As I've said, those have 2 separate I2C buses, and they are not connected together.
You have to connected them together yourself.
I2C address of most of AT24Cxx is 0x50.
I strongly suggest to download PDF specs of both chips.

Everything up & running. Thanks again.
Just one small problem:
How should I erase eeprom? I mean with programming.

Unlike Flash which need to be erased or page-erased before writing, EEPROM doesn't have such limitation, so you can write them directly. If you still wish to erase the content for security reason, simply write zeros all over the places.