raspi-config --------------------------- Interfacing Options I2C enable ---------------------------- nano /boot/config.txt add at end -------------------------- # Enable HWclock dtoverlay=i2c-rtc,ds3231 ------------------------- nano /lib/udev/hwclock-set comment out -------------------------- if [ -e /run/systemd/system ] ; then exit 0 fi ------------------------- Good to know: read time directly from rtc module hwclock -r update rtc module time from system time (system time should be regularly updated by ntp from the internet if your pi is networked): hwclock -w update system time from the rtc module (this should happen on startup): hwclock -s and the most fun of all - monitor the "drift" between your system clock and the rtc module: hwclock -c