Help to setup ADC for 16F1826

[Aussie Barry]

Two things I have noticed in your code:

1/. The 16F1826 has a 10 bit ADC whereas you have defined an 8 bit setup
2/. ADCCON0 = %00001001 sets the ADC channel to be AN9 where you are trying to use AN2

Cheers
Barry
VK2XBP

[SOTASOTA]

Hey Barry!
Thanks so much!!!
This did it!

DEFINE OSC 4
DEFINE ADC_BITS 10 ' 10 bit A/D Conversion
DEFINE ADC_CLOCK 4
DEFINE ADC_SAMPLEUS 50 ' 50 uS A/D sample time

PORTA = 0
PORTB = 0
TRISA = %00101100
TRISB = %00000000
ADCON1 =%11000000 'Right justified

ANSELA =%00000010 ' AN2 on PortA.2 analog
ANSELB =%00000000 ' Digital inputs

I actually thought you could tell a 10-bit ADC to work as an 8-bit. But no worries! All is perfect once again!!

[Sherbrook]

Hi SOTATOSA
10 bit A/D converters do work in 8 bit mode. Just set LEFT justified and the 8 MSBs are held in the ADRESH register and the 2 LSBs are held in the ADRESL register bits 6 and 7 which you ignore. ADRESH register contains the 8 bit result. I think this is how DEFINE ADC_BITS 8 works. Setting 8 bit conversion AND RIGHT justified would cause some confusion. Hope this helps.
Phil

[Heckler]

this tutorial helped me understand A/D a little better...

http://www.microcontrollerboard.com/...converter.html

and here is another good tutorial...

http://www.edaboard.com/nextoldesttoentry1570.html

[SOTASOTA]

Thanks for all the replies. Making some kind of sense now! :-)