At 11:14 a.m. 16/12/01 -0500, you wrote:
>Well, your rate is so low that you can measure the period in software.
>You can either use the capture compare, or just catch the times in
>software. Say you have a 100uS timer tick. At 1/6Hz, or 6Sec, you will
>have a 1 in 60000 resolution.

Well, thank you for your suggestion, I have been thinking about this=20
possibility,
but, there is a little problem with this, l may be didn=B4t explain that=20
well, I have to
measure pulse length from 60 sec (1pulse/min) up to may be 200msec=20
(300pulse/min).
The condition is, that I have a refreshed display every lets say 5 sec.=20
Given that
the pulse width using the capturing tool, has to be within 50 to 65500=20
clock cycles,
what would be my system clock ?
Anyway I do have the processor quite busy doing the counting for the 2=20
counters, and
especially the multiplexing for the 4 displays out there. There quit a bit=
=20
of timers
and monoflops going on, anyway the RB bus is completely occupied. This will=
=20
probably
make accurate measurement imposible.
So i figured I have to get in with a multiplied number of pulses, let=B4s=
 say=20
real world input
is 1 pulse per minute ( I can=B4t really make my customer wait 60 seconds to=
=20
get the result)
I need to make this at least 8 pulses to come down to 7.5 sec time base,=20
better I multiply
by 16 and have a 3.75 sec time base (refresh if you want so). Of course the=
=20
displayed
result will be wrong for the first couple measurments (btw the pulse number=
=20
will not change
rapidly, they regulate that to a value and there it stays for hours).
Why do I need a time base value as lets say 7.5 sec, lets look at the other=
=20
end, lets say
100 pulse/min, I can not justify to have that updated each 60 sec or 30=20
sec, even 15 sec is a
lot.

You get me now ?

Thank you anyway

Friedel
>Capture the edge to edge on the RB0 pin,
>or just poll, and run a counter in Timer0. You will have a fresh value
>every pulse, or every 6 Sec. If you are concerned about bogus readings
>or bobble on the display, then low pass filter the readings with an IIR
>style filter.
>
>Chris~
>
>Friedel Bruening wrote:
> >
> > Hi all,
> > I need to multiply some incoming pulses, let4s say ther are coming
> > in 10 pulses per minute, but I need to display this as 10 pulse/min
> > on a lets say 5 sec time base, means all 5 seconds I need to have
> > the calculation done and display the result.
>
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