Issue with RTC retaining time

Troubleshooting
1

Using both the Electron and Photon, I’ve got a CR2032 hooked up to the VBAT line to keep the RTC retained through power cycles. However, when I restart the device and call Time.isValid() it returns false; the time is also not correctly set (reads Jan 1, 1990 or whatever). What could be the reason for this? Anything I can debug? I’ve checked the connection several times and have verified there is 3V on VBAT when the device is powered off. I have also remove the 0 ohm resistor on the Electron…

2

It shouldn’t be required but you could try adding

STARTUP(System.enableFeature(FEATURE_RETAINED_MEMORY))

Also what system version are you running?

Sorry for the stupid question, but you have the negative pole of the cell connected to GND too?

3

Yup, the negative poll is connected to Ground (and verified). I am running OSv0.7.0 and already have that line in the firmware:

void startup() {
    System.enableFeature(FEATURE_REATAINED_MEMORY);
    System.enableFeature(FEATURE_RESET_INFO);
}

STARTUP(startup);
4

It should actually be

STARTUP(startup()); // <-- don't forget the parentheses
5

Did you remove the 0 Ohm resistor that ties Vbat to the 3.3V line? It’s #3 shown here.

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image1438×1902 136 KB

6

@LabSpokane, he did!

2 Likes
7

Sorry. That line didn’t show on my mobile. Apologies.