Analog input problem

[burak450]

Hi everybody,

When I use this code i get correct results

DEFINE LCD_DREG PORTB
DEFINE LCD_DBIT 0
DEFINE LCD_RSREG PORTB
DEFINE LCD_RSBIT 4
DEFINE LCD_EREG PORTB
DEFINE LCD_EBIT 5
DEFINE LCD_BITS  4
DEFINE LCD_LINES 2
DEFINE OSC 4                                                                       
DEFINE ADC_BITS     8       
DEFINE ADC_CLOCK  3       
DEFINE ADC_SAMPLEUS 100
bilgi var byte
red var byte
green var byte
blue var byte
flag1 var byte
flag2  var byte
flag3 var byte
SYMBOL VERI=PORTA.0
ADCON1=2
TRISA=%00000001 
TRISB=0
PORTB=0
TRISC=0
LCDOUT $FE,1 




yap:

flag1=0 
flag2=0
flag3=0

high PORTA.1
PAUSE 750
CALL ADC_OKUMA
red=bilgi
pause 5
low PORTA.1


high PORTA.2
PAUSE 750
CALL ADC_OKUMA
blue=bilgi
pause 5
low PORTA.2


high PORTA.3
PAUSE 750
CALL ADC_OKUMA
green=bilgi
pause 5
low PORTA.3


 
pause 7000

goto yap



ADC_OKUMA:
ADCIN VERI,bilgi
RETURN

But I cannot use porta.5 and get wrong results
Where am I wrong adcon1 settings or something else???

DEFINE LCD_DREG PORTB
DEFINE LCD_DBIT 0
DEFINE LCD_RSREG PORTB
DEFINE LCD_RSBIT 4
DEFINE LCD_EREG PORTB
DEFINE LCD_EBIT 5
DEFINE LCD_BITS  4
DEFINE LCD_LINES 2
DEFINE OSC 4                                                                       
DEFINE ADC_BITS     8       'A/D çevirim sonucu kaç bit olacak
DEFINE ADC_CLOCK  3       'Clock kaynağı (3=rc)
DEFINE ADC_SAMPLEUS 100
bilgi var byte
red var byte
green var byte
blue var byte
ADCON1=2
input PORTA.5
SYMBOL VERI=PORTA.5 
TRISB=0
PORTB=0
TRISC=0
LCDOUT $FE,1 



yap:

high PORTD.7                    
PAUSE 750
ADCIN VERI,bilgi
red=bilgi
pause 5
low PORTD.7


high PORTD.6
PAUSE 750
ADCIN VERI,bilgi
blue=bilgi
pause 5
low PORTD.6


high PORTD.5
PAUSE 750
ADCIN VERI,bilgi
green=bilgi
pause 5
low PORTD.5

CALL GOSTER











 


   
pause 7000
goto yap

 ADC_OKUMA:
ADCIN VERI,bilgi
RETURN 

GOSTER:
LCDOUT $fe,2,#red," ",#blue," ",#green," "

RETURN

[burak450]

By the way I just tried adcon1=0 it didnt work again...How can I use porta.5 as analog input ????

[mister_e]

Knowing your PIC model would help us.

[burak450]

my pic is 16f877a

[burak450]

ı wrote this code.


What i see on lcd is the values getting bigger .Started 90,100,108,120,145

How can i use first analog five input pins in 16f877a...

DEFINE LCD_DREG PORTB
DEFINE LCD_DBIT 0
DEFINE LCD_RSREG PORTB
DEFINE LCD_RSBIT 4
DEFINE LCD_EREG PORTB
DEFINE LCD_EBIT 5
DEFINE LCD_BITS 4
DEFINE LCD_LINES 2
DEFINE OSC 4
DEFINE ADC_BITS 8
DEFINE ADC_CLOCK 3
DEFINE ADC_SAMPLEUS 100
SYMBOL VERI=PORTA.5
deneme var byte
ADCON1=10000010
TRISA=%11111111
basla:
LCDOUT $FE,1
adcin veri,deneme
LCDOUT $fe,2,#deneme," "
pause 3000
goto basla

end

which setting is wrong ???

[mister_e]

1. you have to set trisa.5 to 1, make this pin as input
2. choose an ADCON1 setting that set AN4 as analog, =0 or =2 have to work
3. make sure analog comparator is disable. CMCON=7
4. use ADCIN with analog channel number, not his pin name
ADCIN 4, YourVariable

HTH

[burak450]

I wrote this but same problem continues.the value starts 111 gets bigger and bigger up to about 249-254

DEFINE LCD_DREG PORTB
DEFINE LCD_DBIT 0
DEFINE LCD_RSREG PORTB
DEFINE LCD_RSBIT 4
DEFINE LCD_EREG PORTB
DEFINE LCD_EBIT 5
DEFINE LCD_BITS  4
DEFINE LCD_LINES 2
DEFINE OSC 4                                                                       
DEFINE ADC_BITS     8       
DEFINE ADC_CLOCK  3     
DEFINE ADC_SAMPLEUS 100
deneme var byte
ADCON1=2
trisa.4=1
CMCON=7 
basla:
LCDOUT $FE,1 
adcin 4,deneme
LCDOUT $fe,2,#deneme," "
pause 3000
goto basla