NNTP-Posting-Date: Sat, 11 Jan 2003 10:09:29 -0600
From: firstname.lastname@example.org (John Fields)
Subject: Re: Counter Skipping.....
Date: Sat, 11 Jan 2003 15:41:51 GMT
Organization: Austin Instruments, Inc.
References: <email@example.com> <firstname.lastname@example.org>
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On Fri, 10 Jan 2003 23:55:38 -0700, William
>William : Ok .....John The main purpose is to see visual reset counter
>for an alarm circuit. I wanted to make it brief becuase all I need to
>know is how to improve the the enable signal to the Pic12C508 from
>the ones counter (enable or carry out signal) to the tens counter.
>Basically it comes down to 2 Pic's working in sync, with two different
>programs on board for each Pic12C508. First, one to detect the enable
>line or input to subtract 1 in the tens counter. like 5,4, 3 etc. Once
>the ten and one counters reach zero, then this signal from both pic's
>is sent into an AND Gate which then switches on a relay(power down).
>At this point in time, both programs loop forever. I could take
>advantage of the sleep mode. I didn't...........Oh well.
>The work is divided in half for this counter, I could of placed all
>the code one IC perhaps, but there is another reason as well.
>It gives me 2 reset lines instead of one.(Pin 3 on the 508)
>The advantage of this is that I can see where the count stopped
>and why........Because half the counter will latch up and freeze on
>the count.................... Some of you may not agree :)
>I wrote this code on purpose to do just that.
>Make sence ? I hope I was clear on this..........................
>If your wondering there are 4 lines used to drive the MC14511,
>and I won't explain this, because it's in any text book.
>The heart of the matter: The signal line to enable the pic
>to move forward, meaning to display 5 then 4 then 3 etc.
>to reach the end of the program.
>The CR time constant should it be longer or shorter than one
>I'm using now?
Well, William, I'm still at a loss as to why you've decided to go
the way you have, when it seems to me there may be many more less
trouble-fraught ways to accomplish your goal which, as I understand
it, is a 2 digit display and an event counter which counts down and
powers something down when it gets to zero.
In any case, thanks for the description, but count me out.
P.S. If it's only a question of the RC time constant, _try_
different ones until you get something that works...
Professional circuit designer