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Variable Time to Read Timer1 Counts

 
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Chicky



Joined: 04 Aug 2005
Posts: 21

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Variable Time to Read Timer1 Counts
PostPosted: Mon Mar 03, 2008 1:35 am     Reply with quote
Hi All..

I have a problem in setting time to count pulses in Timer 1..
This is how I usually do it:

Code:
   setup_timer_1 ( T1_EXTERNAL | T1_DIV_BY_1 );
   count=0;
   set_timer1(0);

   output_low(S2);
   output_low(S3);

   delay_ms(200);
   count=get_timer1();


This means I'll count incoming pulses to my pin15 of pic16f877a for~200ms.. But right now I need to vary the time because it depends on other factors.. I guess I cant use delay_ms() anymore right? How to do it then? Confused

Please help... TQ soo much Very Happy
ckielstra



Joined: 18 Mar 2004
Posts: 3680
Location: The Netherlands

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PostPosted: Mon Mar 03, 2008 5:51 am     Reply with quote
Quote:
But right now I need to vary the time because it depends on other factors.. I guess I cant use delay_ms() anymore right?
Do you know ahead how long the delay needs to be? If yes, you can vary the time by passing delay_ms() a variable instead of a fixed constant.

For a more detailed help you will have to explain to us what the 'other factors' consist of.
ChickymEAL
Guest
PostPosted: Mon Mar 03, 2008 6:41 pm     Reply with quote
The 'other' factor is actually an input from sensor.
I need to count incoming pulse from sensor for certain period of time, then based on the number of pulse I'll need to adjust the time period to count the next incoming pulse..

The time period is adjusted by using bisection method (but thats a different story).. The important part is i need to vary the time to count the incoming pulse...

Any idea? I'm quite at dead end here.. Please advice..
Guest
PostPosted: Mon Mar 03, 2008 8:34 pm     Reply with quote
ckielstra wrote:
Do you know ahead how long the delay needs to be? If yes, you can vary the time by passing delay_ms() a variable instead of a fixed constant.


Ermm.. how do I do that? Is it like this:

Code:
x=1000;
delay_ms(x);


I've tried this before n it does not work..
PCM programmer



Joined: 06 Sep 2003
Posts: 21708

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PostPosted: Mon Mar 03, 2008 8:49 pm     Reply with quote
Do you have version 3.xxx of the compiler ? (Instead of 4.xxx)
If so, see this thread for links to delay routines that accept 16-bit variables.
http://www.ccsinfo.com/forum/viewtopic.php?t=32288
Chicky



Joined: 04 Aug 2005
Posts: 21

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PostPosted: Tue Mar 04, 2008 12:38 am     Reply with quote
ooook..
I've updated my compiler n it works! Yay!

Thanks a lot guys~ Very Happy
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