I have not found a library that will drop directly into the SDK, but there are several libraries out there that you can look at for inspiration. You will also want to look at the TWI master driver for handling the I2C communication with the DS1307.
If you intend to power the nRF at all times (which is the case for most products), it could be an option to use the internal RTC instead of a external RTC. You would have to handle the complexities of date and time, such as adjusting for months with fewer than 31 days and corrections for leap year in software, but the accuracy will be just as good as using the DS1307 (as it only depends on the 32 kHz crystal).
I see. The RTC of the nRF will not work when the power supply is lost. That sort of applies to the DS1307 too, but there you have the optional backup supply, and moreover, the current consumption of the DS1307 when in battery backup mode is lower than you would get for the nRF5.
It is difficult to say anything about the error you get returned when calling nrf_drv_twi_rx() or nrf_drv_twi_tx(). However I wander if you called nrf_drv_twi_init() before? With what parameters?
I see. The RTC of the nRF will not work when the power supply is lost. That sort of applies to the DS1307 too, but there you have the optional backup supply, and moreover, the current consumption of the DS1307 when in battery backup mode is lower than you would get for the nRF5.
It is difficult to say anything about the error you get returned when calling nrf_drv_twi_rx() or nrf_drv_twi_tx(). However I wander if you called nrf_drv_twi_init() before? With what parameters?
