Measuring long pulse widths with BS2p40

Archiver

I need to measure pulse widths in the 500 ms range and the max pulse
width that the 2p40 can measure is 49.125 ms with the pulsein
command. How can I accurately measure these long pulses with the
stamp then? Accuracy is important, in the range of +-500us. Any help
is welcome.

Basically I am trying to measure the rise time, Time on, fall time,
and time off of a pulsed vacuum using a SenSym pressure transducer. I
am going to use window comparitors for each of these phases and feed
that into the stamp. The frequency of the waveform is about 1Hz.

Can the stamp handle this task or have I chosen poorly?

Jason

Archiver

You should have no trouble achieving that accuracy on the BS2p with a
coded timing loop. See this URL for some comments and caveats:
http://www.emesystems.com/BS2speed.htm#longpulse

-- Tracy

>I need to measure pulse widths in the 500 ms range and the max pulse
>width that the 2p40 can measure is 49.125 ms with the pulsein
>command. How can I accurately measure these long pulses with the
>stamp then? Accuracy is important, in the range of +-500us. Any help
>is welcome.
>
>Basically I am trying to measure the rise time, Time on, fall time,
>and time off of a pulsed vacuum using a SenSym pressure transducer. I
>am going to use window comparitors for each of these phases and feed
>that into the stamp. The frequency of the waveform is about 1Hz.
>
>Can the stamp handle this task or have I chosen poorly?
>
>Jason

Archiver

Why wouldn't the "count" instruction work ?

Mike