16 x 2 OLED with RTC

[johnrelph]

Just received the above & set up the time and it runs just fine, until I insert the backup battery and the clock display freezes until it is removed and the time returns to the correct time,
Is it a faulty unit or have I overlooked something,
Any advice would be appreciated.

 

[nick12ab]

You haven't overlooked anything. Rev-Ed (this is the AXE033, right?) overlooked the consequences of adding a diode (which has a significant voltage drop) in series with something that requires 5V or near to 5V which the DS1307 does when the backup battery is fitted due to it preventing any access to it via the i2c bus when the power supply voltage is below a level determined by the battery voltage.

To bypass the diode, solder a wire link to the PWR header.

 

[johnrelph]

Thanks for the reply nick,
Yes it is a AXE033Y, I have a jumper on the power header,
Problem solved!
Thanks to your post about power supply voltage, I was running it with 3 rechargable AA cells = 3.6v changed to 3 ordinary batterys = 4.5v AOK.