Normally the due IO pins only can stand 3.3 V, but what about the I2C? Can i use the bus with 5V? i cannot find a good documentation about the I2c specification for the due.
Why do say DS1307 is 5V only? Datasheet indicates it will work much lower:Logic 1 Input, VIH: 2.2 to VCC + 0.3VLogic 0 Input, VIL: -0.3 to +0.8VLooks like a 3.3V capable part to me.