milli seconds

[KarlZeilhofer]

to synchronize millis() with the second(), I used following workaround:

while(millis()%1000); // wait for milli seconds to be zero before setting new time. setTime(hour, minute, second, day, month, year);

hope this helps someone.
now you can print the time with milli seconds resolution.

[bojh]

... for an exact given second at time, second should be incremented by +1 before setTime().

@PaulStoffregen an alternative would be to enhance API by a additional method.
Proposal:

time_t milliSec() { now(); return(millis()-prevMillis); }

Pro: exact (no offset!) and everybody can find and use it.
Con: more computation! ... vs. delayed sync and simple millis().

[cyberman54]

while(millis()%1000); // wait for milli seconds to be zero before setting new time.

@KarlZeilhofer What happenes on a multitasking RTOS system, where we can miss the one moment when millis()%1000 = 0 ?