Analog input problem

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- 27th February 2009, 15:20
burak450

Analog input problem

Hi everybody,

When I use this code i get correct results

Code:

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???

Code:

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
- 27th February 2009, 15:34
burak450

By the way I just tried adcon1=0 it didnt work again...How can I use porta.5 as analog input ????
- 27th February 2009, 17:08
mister_e

Knowing your PIC model would help us.
- 27th February 2009, 17:10
burak450

my pic is 16f877a
- 27th February 2009, 17:13
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...

Quote:

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 ???
- 27th February 2009, 17:20
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
- 27th February 2009, 17:31
burak450

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

Code:

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
- 27th February 2009, 17:43
mister_e

try ADCON1=%11100010
- 27th February 2009, 17:57
burak450

i tried this it worked !

deneme var byte
ADCON1=0
trisa.5=1
CMCON=7
basla:
LCDOUT $FE,1
adcin 4,deneme
LCDOUT $fe,2,#deneme," "
pause 3000
goto basla

after that i tried this it didnt work
values is getting smaller now..
its so weird

bilgi var byte
red var byte
green var byte
blue var byte
ADCON1=0
trisa.5=1
trisa.1=1
trisa.2=1
trisa.3=1
trisa.0=1
CMCON=7

TRISB=0
PORTB=0
TRISC=0
TRISD=0
LCDOUT $FE,1

yap:

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

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

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

CALL GOSTER

pause 7000
goto yap

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

Where am i wrong this final code???
- 27th February 2009, 18:02
mister_e

In the first you have ADCIN 4, the second you have ADCIN 5.

What is your analog source? Any available schematic ?

You want to use GOSUB instead of CALL. don't forget the RETURN as well.
- 27th February 2009, 18:11
burak450

sorry. i put code there imcomplete.there is a "return" at the end.i saw this picture .there is RA5 after RA3.thats why i used porta.5.do you have any idea why did it work with first code and didnt with second???

http://img18.imageshack.us/img18/8128/adszbby.jpg
- 27th February 2009, 20:16
HYETİK

I saw and I experience that my friend's a pin of pic16f877 was not working. Only one pin was not working:) others are works well may be u should change your pic:)

so weird:)
- 27th February 2009, 20:19
HYETİK

when my friend changed his MCU hic circuit worked well.
I was shocked when I saw it