On 2/28/2013 6:03 PM, Chris Adams wrote:
Once upon a time, Ralph Aichinger <ra...@pangea.at> said:
Has anybody *two* GPIO PPS devices on different GPIO
pins on their Raspberry Pi? Would a setup like this
enable the ntpd to check the devices against eachother
(or probably more likely give an idea of interrupt
handling capabilities)?
Remember: a man with two clocks never knows what time it is.
If they are the same, everything's great; if they are different, what do
you do?
This looks so simple!!! Is there a "catch" somewhere?
Try adding a third clock. If NO TWO CLOCKS AGREE
you have a serious problem.
If you are relying on time from the Internet, that
may be your one of your problems!!!
I use a Global Positioning System (GPS) Timing Receiver
and get time good enough for most purposes.
It's specified +/- 50 nanoseconds.
If you need better, you can get it but you have some
studying to do and you had better have a "deep pocket"!
If your "deep Pocket" is not full of $1000 bills. . . .
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