> I really need to design a product that knows the official U.S. time,
aside
> from other features. Can someone tell me what is required for the
hardware
> and software to acquire the official time? And what kind of connections
are
> required?

There are several ways to do this, but you need to first decide what
accuracy you require.  If the gizmo already has an internet connection,
then the contacting a NNTP server requires no additional hardware.  There
are other options:

1  -  Have the user set it occasionally and use a real time clock in
between.

2  -  Decode the WWVL long wave broadcasts.  These are designed for this
purpose, but your hardware is susceptable to antenna orientation and
distance from Boulder.  Here in MA we are 2000 miles from Boulder and
placement and orientation of automatic clocks makes a big difference.  I
have two automatic clocks, and they only seem to pick up the signal at
night, sometimes.

3  -  Decode WWV broadcast.  These are at several shortwave frequencies.
I know 10MHz is one of them, and I think there are also broadcasts at
2.5MHz, 5MHz, and 15MHz, but I'm not sure.  These may be more difficult to
decode, but the coverage should be wider.  I'm not totally sure they even
have encoded data on them.

4  -  Canada also broadcasts a time standard.  The radio station is called
CHU if I remember right.  I don't know whether it contains coded
information that a micro can use.


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