Quote Originally Posted by malc-c View Post

The only part I don't grasp is the $D0 part -
OK now got it...

from the datasheet The address byte contains
the 7 bit DS1307 address, which is 1101000, followed by the *direction bit (R/W ) which, for a write,
is a 0.
I used a binary to decimal / hex convertor.... 11010000 is D0, therefore the $D0 is the address which the PIC looks for to locate the DS1307 on the I2C buss and sets the DS1307 to either receive data or to send it ?