onboard external Real Time Clock on nrf52840

Question

Hello , 
 
 Does nrf52840dk has an onboard external Real Time Clock ..? If yes, I couldn't find it's specifications anywhere in the documentation. Please help with the links. 
 Can I get any sample programs link to interface any external RTC like ds1307 or ds3231 etc,. over i2c with nrf52840dk..? 
 Using nCS. 
 
 Thanks,

runsiv · Accepted Answer

Hi 
 You can have a look at this case . Just remember by default it would not keep the time if the device is reset. If you want to I would look into the following: 
 Using Settings in Zephyr to write something to the reserved flash page before shutting the core and read from the stored value when waking up. You can still use the read value to add on top of the RTC value to get an essence of tracking the time from the start. 
 Regards 
 Runar

onboard external Real Time Clock on nrf52840

Top Replies