hayee
Joined: 05 Sep 2007
Posts: 252
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| wanna know about delay in ADC |
 Posted: Thu Oct 09, 2008 11:30 pm |
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Hi,
I am working on 18f452.I have some Analoge Channels Some digital Inputs.Exactly i want to know that is it necessary to add a delay in adc routine for example
| Code: |
set_adc_channel(2);
delay_ms(5);
ts1=read_adc();
ts2=(ts1*0.488);//ts2=((ts1*5)/1023)*100 => ts2=(ts1*0.488)
rotate_left(&ts2,2);
rotate_left(&ts2,2);
rotate_left(&ts2,2);
rotate_left(&ts2,2);
rotate_left(&ts2,2);
rotate_left(&ts2,2);
rotate_left(&ts2,2);
rotate_left(&ts2,2);
hold_regs[10]=ts2;//loading value of ts2 in holding register
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Here the delay is too much because i want to run the entire program in 55uS.My program consists of 4 analoge channels so it would be take too much time.
i used another technique.i have initialize a counter.when a conter reaches at a particular value it read adc like
| Code: |
set_adc_channel(2);
if(counter==2400)
{
ts1=read_adc();
ts2=(ts1*0.488);//ts2=((ts1*5)/1023)*100 => ts2=(ts1*0.488)
rotate_left(&ts2,2);
rotate_left(&ts2,2);
rotate_left(&ts2,2);
rotate_left(&ts2,2);
rotate_left(&ts2,2);
rotate_left(&ts2,2);
rotate_left(&ts2,2);
rotate_left(&ts2,2);
hold_regs[10]=ts2;//loading value of ts2 in holding register
}
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But by doing this when i vary any one analoge channel by potentiometer all analoge channels varies.
Tell me another way for doing this |
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