Caroma smart toilet isn't filling
It sounds like there's a problem with the inlet valve, which should fill the tank when it falls below the set depth. Here's a video on maintenance for a Caroma Dual Flush:

http://www.caromausa.com/resources/videos/articles/29.php

And here's a PDF on servicing the inlet valve:

http://www.caromausa.com/database/rte/files/QuietFlow%202%20Service%20Guide.pdf