Hi there,
I don’t understand what do you want because in the title you write about USB, and at the end of your post you write about internet.
- Over internet, if you have a Network Interface, you can use a NTP server.
- Over USB, you can send the time in seconds via terminal.
- With some limitations is also possible to use “Compilation time” as a starting time
printf("Time is: %s %s\n",__TIME__,__DATE__);
- Probably most fun is Radio clock, but it takes some time for synchronization.
BR, Jan