Gerhard Fiedler wrote:
>
> At 09:02 07/11/96 +1100, Peter Homann wrote:
> >I think the problem is that the output of serial data will be
> >corrupted by the interrupts.
>
> Didn't you say that you need to send only in quite big intervals? How about
> stopping measuring while sending data, if there really is a timing problem?

Although I wish to initially  transmit approximately once every
five seconds, eventually I would like to speed it up. Otherwise I
could restart the measurement after the transmission has finished.

At 20 rpm the period is 3S. The worst case is when the pulse is
missed during transmission and the next pulse is not for another
3 seconds, then the next pulse is another 3 seconds a delay of
6 seconds before the frequency value is calculated.

If necessary I can live with this but its not ideal.

I plan to transmit the signal at a random interval, averaged at
once every 5 seconds. It would be nice to have the "Current"
value ready for when the transmission is required.

The reason for the random transmission is that there is more than one
unit transmitting. A poor mans ethernet with no collision detection
by the sender. If the receiver get a screwed message it ignores it
and picks up the value on the next transmission.



--
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Peter Homann   email: peterh@adacel.com.au       Work : +61 3 9596-2991
Adacel Pty Ltd                                   Fax  : +61 3 9596-2960
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