Synchronize time motes and Option RTC_ALM1_MODE3

Sara Jimenez · **Joined:** Tue Aug 21, 2012 2:03 pm **Posts:** 99

Hi,

How can I do to synchronize the time in two waspmote? I set the time-date in both of them, but they have a time lag of 7 seconds. I need that they have the same time and with function RTC.setTime() I can't do it.

On the other hand, I want to wake up motes at the same time all days. I use:
PWR.hibernate("10:00:00", RTC_ABSOLUTE,RTC_ALM1_MODE3); (to wake up motes at 10:00 am)

But they don't wake up. I don't know what I am doing wrong.

Regards

libelium-dev · **Joined:** Mon Sep 28, 2009 1:06 pm **Posts:** 7472

Hi Sara Jimenez,

the best option to synchronize the motes time is to pick it from the GPS.

Regarding the hibernate time, you are introducing it wrongly, when configuring alarm 1 the date format must always be "dd:hh:mm:ss" (day, hour, minute, second), even if you are not using some of those parameters (in your case it would be something like ""00:10:00:00").

Regards.

Sara Jimenez · **Joined:** Tue Aug 21, 2012 2:03 pm **Posts:** 99

Can I get time and date from GPRS? Or only from GPS?

mlucarelli · **Joined:** Tue Sep 04, 2012 12:35 pm **Posts:** 25

Hi,
I'm interested in the same argument.
libelium-dev say "the best option to synchronize the motes time is to pick it from the GPS".
Well: what if GPS module is not available?
There is another way (not the best) to synchronize mote's clocks?

Thank you.

libelium-dev · **Joined:** Mon Sep 28, 2009 1:06 pm **Posts:** 7472

Hi all,

there is an option with the SIM900 GPRS, the AT command AT+CLTS returns the local timestamp from the network to which it is connected, but we have never tried it and we don't know how accurate it will be.

Regards.