RTC Only Keeping Time When Connected With USB

[KP_999]

This is not the first time I have used the Datalogger, a while back it worked perfectly and did all that I asked of it. However recently I have been logging temperatures in my loft space and intend to do so for another 12 months but I have ran into problems with the RTC on the logger.

Here's the problem:

When the Arduino+Datalogger are running on a 5v power adapter into the Arduino the date recorded on the Datalogger is always 2000/01/01 00:00:00.

The time has been set into the RTC as I've ran the time setting code several times as I have that as a separate file.

If I connect the Arduino+Datalogger to the laptop via a USB cable it only works intermittently. 99% of the time the serial monitor will report the correct date/time but occasionally it will return 2000/01/01 00:00:00 which is adding to the confusion.

I've replaced the battery thinking it was out of power but this hasn't resolved anything.


I'm not sure if it is a power issue as I'm using a 5v power adaptor to power the unit instead of a 9v adaptor and the Arduino also has to power 2 relay switches, however I thought the RTC's time was kept by the coin battery so power issues with a 5v adaptor shouldn't cause this.

I'm so lost with this it's driving me mad any help would be seriously appreciated.

Is it the DS1307 chip going mad or just me?

[adafruit_support_bill]

I'm using a 5v power adaptor to power the unit instead of a 9v adaptor

How do you have the 5v power adapter connected? If your adapter is regulated, you can use it, but you should connect it directly to the GND & +5 pins instead of going through the barrel connector. Going through the on-board regulator will drop the voltage further.