Would this even be possible...

Okay … I was just on the programming forums and saw this debate on time ,rtc’s,and web time… Would it be possible to use a Ethernet Shield to set an RTC so if the internet crashed or you ‘accidentally’ disconnect it the RTC will take over to keep your project going in case the world just failed you could still have brewed coffee waiting on you (lol just an ex.)

Don't see why not. Your code can be smart enough to read the internet time and the battery backed RTC time, and if way off ignore the internet time until you decide its valid again.

If I just left a part out let me draw this out...

IF internet is avalible ETHERNET---> RTC ----> Arduino if not ETHERNETXXXX RTC---->Arduino

-----> means that the first is telling the second what time it is

You’re on the right track but technically Ethernet can’t tell the RTC anything directly. Your drawing should probably be more like this

ETHERNET----> Arduino —> RTC

when you have Enet and

Arduino <— RTC

when you don’t.

In other words the Arduino gets the time from Enet if possible (and optionally uses that info to keep the RTC in sync), then when Enet goes away you get the time from the RTC.


Rob

Well... I believe I haz a new project alongside my clock that can be set 3 different ways

I don't see the point of looking up on the internet every time. Sure, you can do it... but the RTC will probably be more than enough for what you need. Maybe looking up once a day?

This is what your question answer is:

I don't see the point of looking up on the internet every time. Sure, you can do it... but the RTC will probably be more than enough for what you need. Maybe looking up once a day?

or for more accuracy twice or thrice or so on for more and more accuracy..

for some building blocks see - http://www.arduino.cc/playground/Main/DS1307OfTheLogshieldByMeansOfNTP -

Instead of an RTC-chip one could use a Radio-time station-receiver or GPS-module. If reception is good enough you may never need to set the clock again. Using SerialIP an ethernetshield probably won’t be needed…