enable rtc on udoo quad

Hello, I've an UDOO Quad with UDOObuntu installed within.
I would to enable the rtc, so I've bought a button battery with the connector. When the udoo is unplugged from the power source i've connected the rtc battery to "ext bat" connector, then I've powered the board.
After the clock synchronization with online server (sudo ntpdate) the clock is updated but after i have halted and restarted the board the date command returns the original date: 1970.
What's the problem?
Thanks!

 

Hi there,
what sort of rtc battery do you connect to the ext bat connector?

 

the battery has nominally 3V, but fully charged the battery voltage is 3.37V

 

Solved! the rtc battery is disconnected from the circuit because there isn't the Schottky diode that connects the battery to the supply system. I will fix it.

 

So, you are saying that there is a missing component that you found in the schematics, aren't you?

 

Check voltage polarity on the connector side with a meter if possible but... from this image the "positive" side of the cell is clearly that with 2 pins.
you should exchange the "red cable" with the "black cable" on the battery side (on the connector side pins and colors are right).

 

yes, but i think the component was desoldered.

 

dxmann, if you think you received a board with missing parts please open a ticket and we'll give you assistance.

 

ok, thanks