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Analog to Digital conversion?

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Hey there!

I've learned some A-D - and is it a way to let the A-D conversion to a maximum of 4-bits instead of 10-bits?

I searched the tutorials for the PK2 (Pic Kit 2) Lessons but didn't found anything.

Here's the code - I took some from Mike Predko's Evil Genius book and it's default to 10 bits. Anything I should add there? :)

Code:
#include <htc.h>

__CONFIG(INTIO & WDTDIS & PWRTEN & MCLRDIS & UNPROTECT 
& BORDIS & IESODIS & FCMDIS);
  
int main()
{
    ANSEL = 0x01;
    TRISC = 0x00;
    PORTC = 0x00;
    TRISA = 0xFF;
    ADCON0 = 0b000000001;
    ADCON1 = 0b000100000;
    
    int ADCState = 0;
    int ADCValue = 0;
    int array[5] = {0x00, 0x01, 0x02, 0x04, 0x08};
    int i=0;
    
    while(1)
    {
        PORTC = ADCValue;
        
        switch(ADCState)
        {
            case 0:
            GODONE = 1;
            ADCState++;
            break;
            case 1:
            if(!GODONE)
            ADCState++;
            break;
            case 2:
            ADCValue = ADRESH;
            ADCState = 0;
            break;
        }    
    }
}
Btw - the µC is a PIC 16F690. :)
 

3v0

Coop Build Coordinator
Forum Supporter
I am not sure why you would want a 4 bit result?

You can convert the 10 bit result to a 4 bit result by shifting it right 6 times.

You have two sources of information. The ADC section in the datasheet for the processor and the doucmentation for the ADC setup function for the C compiler.
 
Ok, got it. :)

But strangely, when I rammed up the potentiometer to max, it gives me only 1011 output (from the 4 LEDs, and the max output should be 1111). I'm not sure where's the last 3 number goes, but I have typed:

ADCValue = ADCValue >> 4

Is it the conversion too fast, or too slow, or something else? :D
 
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