On Fri, 3 Jan 2014 13:12:52 -0800
Chris Albertson <[email protected]> wrote:
> The TTL level PPS did not work for me when I tried to drive a long cable.
> I used the MAX232 level converter chip to level shift.
>
> Do check the polarity. If you get it wrong it will appear to work but the
> timing will biased by the pulse width. (the falling edges is used if you
> get it wrong. RS-232 levels are backwards from TTL except control
> signals. Just be sure you have the "correct" number of inverter. Then
> when you are done check the time is right.
Also keep in mind that RS-232 relies on the voltage going negative
to encode a "1". I.e. getting 0V is not enough and might only work
by chance with some RS-232 receivers.
Attila Kinali
--
I pity people who can't find laughter or at least some bit of amusement in
the little doings of the day. I believe I could find something ridiculous
even in the saddest moment, if necessary. It has nothing to do with being
superficial. It's a matter of joy in life.
-- Sophie Scholl
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