Hello all,
I have an assembly using a mini L3V7. Since the device is going to work on a seasonal basis and batteries should be disconnected when not in use, I would like the device time/RTC to sync upon re-installation of the device.
I assume this will be happening with a check of the system/rtc time vs the network time difference.
Anyone has any solution to this problem?
Thanks!
Witty Pi's software already provides a net_to_system() function to copy Internet time to local system and a system_to_rtc() function to copy local system time into RTC.
You may call them sequentially in your own BASH script (after including the utilities.sh script) to synchronize Internet time into RTC. If you don't use BASH, you may implement the same functionality with different programming languagues.
Thanks for the response.
After running those functions, I should re-define the schedule to make sure the correct shutoff and turning-on time are set, correct?
Do you see a problem running it at every startup or should I implement a check to assess whether the system/rtc time is off when compared to the network time?
Thanks again!
After running those functions, I should re-define the schedule to make sure the correct shutoff and turning-on time are set, correct?
Yes. This can be done by executing the runScript.sh script then.
Do you see a problem running it at every startup
We do not suggest to do time synchronization so frequently - the accurancy of RTC is good enough, and the time information from Internet is not always good. We have saw many cases that the incorrect time from Internet corrupts the RTC time and broke the schedule. Wrong Internet time information might be due to network issue, or timezone issue etc.
It is recommended to do the Internet time synchronization manually, or automatically after making sure the Internet time is good.
@admin Thanks for your reply.
May I add about internet time synchronization being required when system or RTC time is way off the internet time?
I think it is important to first check and confirm the Internet time is correct, before applying that time to system and RTC.
Usually you can trust the time in RTC and time synchronization is not necessary, as long as the battery's voltage did not drop too low.
If you can not trust the time on RTC, you may query the Internet time multiple times, that way you may detect and filter some bad values before actually writing it into the RTC.
@admin do you have any example code for that I could implement?
In which file do you suggest adding this piece of code?
Before running my application I guess.