https://devzone.nordicsemi.com/f/nordic-q-a/78343/troubleshooting-ds1339-rtc-twi-on-custom-board-with-nrf52832Hello, I am working on a project that I built using the nRF52DK and then created a custom PCB. The software I wrote works on the DK with a breakout board for the RTC and the custom PCB should have the same connectivity. I am getting a negative acknowledgementen-USTelligent Community 13Sun, 08 Aug 2021 19:10:05 GMThttps://devzone.nordicsemi.com/thread/323894?ContentTypeID=1Sun, 08 Aug 2021 19:10:05 GMT137ad170-7792-4731-bb38-c0d22fbe4515:a88b6035-43cf-4656-9022-49dd92a574acjake11212<p>I found the issue.&nbsp; The DS1339 has to operate above a power failure threshold.&nbsp; This threshold is 2.7 for the 3V version of the 1339, and due to resistance in my VDD line my voltage occasionally drops below this threshold which puts the RTC in a state that cannot be accessed.&nbsp; Increasing the voltage to above this threshold returned behavior to work as expected.</p><div style="clear:both;"></div>