Has anyone here written a library for this module which you could share? The design is rather  convoluted using a port expander across the I2C bus, with the Hitachi controller in 4-bit mode. I could reverse engineer this, but would prefer not to expe...

I have a very simple example of using the RTC.  My trouble is I never get an interrupt when the alarm time comes. Clearly there is something very basic I am not getting quite right.  Many, if not all of the examples mentioned in this forum and includ...