16F684 AtoD problem

[hell_pk]

Hi!
I am trying ADC of 16F684 with this simple code.The problem is that the analog input channels are pulled high.I have tried with different registers but all in vain.


PORTC=0
CMCON0=$07
'CMCON0=$00
ANSEL=$00
TRISC=$00
WPUA=$00 'doesnt effect the output
'OSCCON=%1110111

'configure ADC
ADCON1=%01110000
TRISA.0=1
PORTA=$00
ANSEL.0=1

ADCON0=%00000001

Define ADC_BITS 8 ' Set number of bits in result
Define ADC_CLOCK 3 ' Set clock source (3=rc)
Define ADC_SAMPLEUS 50 ' Set sampling time in uS

adval var word ' Create adval to store result
Res Var word


Define LCD_DREG PORTC
Define LCD_DBIT 0
Define LCD_RSREG PORTC
Define LCD_RSBIT 4
Define LCD_EREG PORTC
Define LCD_EBIT 5
DEFINE LCD_BITS 4


Lcdout $fe,1
loop:
ADCIN 0, adval

Res = 2*adval

Lcdout $fe, $80
Lcdout "T:", DEC2 Res,"C" 'text for the line 1

Pause 300
goto loop

[mackrackit]

I think this is all you need to set for this PIC. I have not used one for awhile...

Define ADC_BITS 8 ' Set number of bits in result
Define ADC_CLOCK 3 ' Set clock source (3=rc)
Define ADC_SAMPLEUS 50 ' Set sampling time in uS
TRISA.0=1
ANSEL.0=1

[hell_pk]

I have Set these bits in my program but still the port pins are pulled up.

[mackrackit]

What is your analog source?
Can you post a schematic and your current code?

[hell_pk]

I have already posted the code.Analog source is simply a pot for 1-5V range.

[Archangel]

Hello hell_pk,
Try adding OPTION_REG.7 = 0 to the upper area of you code.

[mackrackit]

I have already posted the code.Analog source is simply a pot for 1-5V range.

Post #1 shows a lot of things but it is difficult to tell where the code is or the things you hace tried. Post your current code in tags like Mr.E suggest.

You have ANSEL set two different ways in post #1. Is that the way you have it in your code?

Did you read and try post #2? Some of the registers PBP handles for you when using ADCIN.