v1.5.14 adds a status indicator for the external real-time clock (RTC). If a DS3231 RTC is detected and in use, the timestamp is now prepended with 0x26 in the payload as well as in the flash log. If there is no DS3231 RTC detected, the timestamp is prepended with 0x25 (as in previous firmware versions).
v1.5.13 adds support for an external real-time clock (RTC).
When using an external RTC, the logged measurement data from your BEEP base will have correct timestamps even when the base is offline and disconnected from the LoraWAN network. This will ensure that the timestamps match when importing and merging the logged data afterwards.
It is recommended to use the Maxim DS3231 real-time clock with a coin-cell battery for backup power (available here). Connect the RTC module to the I2C screw-terminal on the BEEP base PCB as shown: