sorry if i'm wrong understanding your post, but in ds1307 ch bit is in register 00H, however in my experience with ds1307, only leaking backup battery will destroy register value and make the chips stop to works
in my project i have 3 device on the i2c bus at24c256,atmega16(as master),ds1307
but my project works fine for about 1 month but after it the ds1307 stops working
do u have any idea for this problem?
Is the at24c256 still working? Any error flag from the ds1307? As far as I know, 1307 is very durable in many condition including over voltage. That problem could be software, try to control the ds1307 manually (such as setting the clock) and see if there is any response.
the at24c256 is working properly the only error that i get is that after sometimes(about 2 or 3 weeks) the CH bit will be disabled (tie to 1) and i don`t know why? i use bascom to write code for my atmega16 and i defined i2cdelay=10 (100khz clock) for ds1307 data transfer and i2cdelay=1(400khz) for at24c256 data transfering
in my project i have 3 device on the i2c bus at24c256,atmega16(as master),ds1307
but my project works fine for about 1 month but after it the ds1307 stops working
do u have any idea for this problem?
May be ur battery stopped working , strange if no voltage is given to DS1307 battery backup pin(3rd pin) it stops working ,no newbie should make the mistake ,i wasted lot of time on it concentrating on software.....