RE: Re: Rabbit 2000

["Keith Doxey" <ukha@xxxxxxxxxxx>]

Hi Paul,

> 	That?s a problem for me as what I am trying to do is
> monitor at least 3 inputs

Apologies if I have grasped the wrong end of this thread, but as I
understand it, you are trying to count pulses from utility meters.

The problems as I understand them are that the pulses are quite short
(hence
your use of a 555 monostable to lengthen the pulses) and also the time
between pulses varies greatly depending on usage.

How about this as an alternative idea.....

use the meter pulses to clock a Flip-Flop

Pulse 1 - flipflop goes high
Pulse 2 - flipflop goes low
Pulse 3 - flipflop goes high

etc

I dont know what the maximum pulse rate is that you expect but assuming it
is one pulse every 10 seconds then just look at each of the flipflops more
often than that eg every second.

If the state of the flipflop is different to the last time you looked at
it,
increment your count.

That way you dont "have to be there" when the pulse happens, you
just need
to know that it DID happen.

Regards

Keith