I know the procedure to enable an external RTC, but I just wonder which are the available supported chip (in config.txt and to use with modprobe).
Where can I find such a list?
/boot/overlays/README particularly the
DO NOT use
modprobe use Device Tree!
Pick any of the listed modules.
ds3231 which is a good performer and works from 3.3V, although many of the others work well.