Adding a RTC to the emonPi

The emonPi updates its internal linux time from NTP when connected to the internet. However if the emonPi is to be used on an offline network or for an application when accurate timestamp is essential then a hardware Real Time Clock (RTC) can easily be added to the Pi's GPIO. We have tested using a DS3231 based RTC module. This RTC module communicates with the emonPi via I2C, it can be easily connected as follows by soldering a four-pin header onto the emonPi aux GPIO pins:

emonPi with hardware RTC module added

DS3231 based RTC module

I2C bus scan showing LCD & RTC

Full install guide can be found on the wiki:
http://wiki.openenergymonitor.org/index.php/EmonPi#Adding_a_Real_Time_Clock_.28RTC.29