Well what do u recommend?
Should I buy another ds1307 module or ds3231 module...actually ds1307 was cheaper hence I had bought it. I'm not using a breadboard in the project so I don't think that the connection is bad. I can try to build a the same thing with new parts but it would take a lot of time (weeks) and I think it doesn't make sense to buy all the modules again...I know that my arduino uno works fine as I have used it many times. I have also used the cable a few times so I think there is no problem with that.
Can u give some examples of I2C devices?