Hi Magnus,

1.
Whats a 'read error' ?
E.g. SDA or SCL permanent low or what ?

2.
Have you tried my I2C-reset-routine after such errors ?

3.
Send you always ACK to read a byte and NACK to read the last byte ?

4.
Have you correct calculated all the minimal timings ?
Most EEPROMs are able to work up to 400kHz or 1Mhz but the DS1307 only at max 100kHz.

5.
I know not the DS1307 data sheet. But most other RTC circuits are busy anytime, if a new time and date was calculated. And then a busy signal was generated to tell, that now the time information may be invalid.


Peter