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Joris H
Joined: 24 Sep 2003
Posts: 14
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| Delay_ms and PIC12C671 |
 Posted: Sun Apr 18, 2004 6:50 pm |
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Hi,
In the following code it seams the the delay_ms is not working. Any Idea what I am overlooking here?
thanks
Joris H.
h.file:
include <12C671.h>
#device PIC12C671 ADC=8
#fuses NOWDT,PUT,INTRC,NOMCLR
#use delay(clock=4000000)
c.file:
void main() {
int SetDly,i;
setup_adc_ports(AN0_ANALOG);
setup_adc(ADC_CLOCK_INTERNAL);
set_adc_channel(0);
output_high(TRHRLY);
output_high(SafRLY);
SetDly = read_adc();
delay_ms ( 100 );
while ( input(Sensor) );
{
output_low(TRHRLY);
for (i=SetDly;i==0;i--)
{delay_ms ( 1180 );}
delay_ms ( 2000 );
output_low(SafRLY);
}
} |
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Neutone
Joined: 08 Sep 2003
Posts: 839
Location: Houston
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| Posted: Sun Apr 18, 2004 7:12 pm |
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Loosely translated these are the same.
for (i=SetDly;i==0;i--)
I = setDelay;
While(i==0)
{ .....
I--;
} |
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Ttelmah
Guest
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| Re: Delay_ms and PIC12C671 |
| Posted: Mon Apr 19, 2004 1:59 am |
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| Joris H wrote: | Hi,
In the following code it seams the the delay_ms is not working. Any Idea what I am overlooking here?
thanks
Joris H.
h.file:
include <12C671.h>
#device PIC12C671 ADC=8
#fuses NOWDT,PUT,INTRC,NOMCLR
#use delay(clock=4000000)
c.file:
void main() {
int SetDly,i;
setup_adc_ports(AN0_ANALOG);
setup_adc(ADC_CLOCK_INTERNAL);
set_adc_channel(0);
output_high(TRHRLY);
output_high(SafRLY);
SetDly = read_adc();
delay_ms ( 100 );
while ( input(Sensor) );
{
output_low(TRHRLY);
for (i=SetDly;i==0;i--)
{delay_ms ( 1180 );}
delay_ms ( 2000 );
output_low(SafRLY);
}
} |
First comment. You select the ADC channel, and then only two instructions latter 'read' the ADC. The capacitor in the ADC circuit, takes time to charge. Normaly you need to allow about 10mSec for this. I'd expect the 'read_adc', to allways return a very low value (assuming the capacitor is charging from 0v), so your loop counter will be programmed with a value of perhaps 0 or 1, and lead to a short delay being seen.
Split the 'delay_ms(100)' instruction, put a delay of perhaps 80mSec, before selecting the ADC, then 20mSecin front of the 'read_adc'. Remember that the external circuitry, will need time to start working.
Seperately, your test in your loop statement is wrong. The second statement in a 'for', is the condition to be met to loop. You need to test for i!=0, to count down from the ADC value.
There is nothing wrong with the 'delay', just in the program using it.
Best Wishes |
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Joris H
Joined: 24 Sep 2003
Posts: 14
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| Delay_ms and PIC12C671 |
| Posted: Mon Apr 19, 2004 6:31 pm |
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Hello,
I put the delay time in the code as proposed and changed the "for" conditions.
It didn't make a difference. Were I am the most confused with is the second delay_ms(2000). As soon as I enter the "while" loop the two RLY go to low. When the ADC doesn't work or =0 then I need still to have those 2 sec delay what I don't have. Any idea?
Thanks
Joris H |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Mon Apr 19, 2004 6:51 pm |
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Post the statements where you define these values:
TRHRLY
SafRLY
Sensor |
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