Adcon register with P18F4550

[lerameur]

Hi ,

I am trying to use A/D conversion, but my code compiles but does not even get to main loop when I add ADCON1 AND ADCON2 registers, these are valid registers in this pic, anybody knows why?

ADCON0 = %11000001 ' AN0, Configure and turn on A/D Module
'ADCON1 = %10001001 ' Analog input
'ADCON2 = %10000001 ' Right justified results for 10 bits,Fosc/8

K

[mackrackit]

ADCON0 and ADCON1 bits 6 and 7 should both be 0.

Are you using ADCIN or working the registers? Show your code.

[lerameur]

Ok Thanks , I wiil try it, but the datasheet sheet says: bit 7-6 Unimplemented: Read as ‘0’ .. shouldn't there be no difference as what is there?
ok work now, but gives me an 8 bit result instead of 10 bit

K

[lerameur]

Ok Thanks , I wiil try it, but the datasheet sheet says: bit 7-6 Unimplemented: Read as ‘0’ .. shouldn't there be no difference as what is there?
ok work now, but gives me an 8 bit result instead of 10 bit

I also have these defines in the prog:
Define ADC_BITS 10 ' Set number of bits in result
Define ADC_CLOCK 3 ' Set clock source (3=rc)
Define ADC_SAMPLEUS 50 ' Set sampling time in uSec

K

[mackrackit]

Adcon2.7=1

[lerameur]

ya thats what i had before I commented out. See I have 2.23v on pin ANA5 and it reading 93 on the LCD


K

[lerameur]

I change a bit of the program , but i am still getting 8 bit results ( max 255)

Define ADC_BITS 10 ' Set number of bits in result
Define ADC_CLOCK 3 ' Set clock source (3=rc)
Define ADC_SAMPLEUS 50 ' Set sampling time in uSec

ADCON0 = %00000001 ' AN0, Configure and turn on A/D Module
ADCON1 = %00001001 ' Analog input
ADCON2.7 =1 	   ' Right justified results for 10 bits,Fosc/8

Check_voltage_Low:
ADCON0 = 00010001 'Start Conversion
ADCON2.7 =1
ADCIN 4, voltage_check 'analog pin 4 get the 10 bit result  Check the battery voltage on pin PORTA.5

lcdout $FE,1, "Battery voltage"
lcdout $FE,$C0, "TempC: ",  dec voltage_check
pause 1500
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