ADC 12F683

[javi.ar]

Hello everybody:
I´m using a 12f683 and reading ADC from a LM35, but the reading is always the same no matter what I read (GND or VCC) , I used all 3 AD inputs and set all analog. No success so far , I am using CCS 3.23 .
Thanks in advance to everybody.

[PCM programmer]

[javi.ar]

Sorry Version is 3.235
I use read_adc() for reading ADC output.

[PCM programmer]

I don't see any problems with the A/D code or the CCS setup code
for your version of the compiler. So you need to post a test program.
Make it be complete but short. (like 20 lines, total).

[javi.ar]

Here is all the code...

#include <12F683.h>
#include <ini12F683.h>
#device adc=8

#FUSES NOWDT //No Watch Dog Timer
#FUSES INTRC_IO
#FUSES NOCPD //No EE protection
#FUSES NOPROTECT //Code not protected from reading
#FUSES MCLR //Master Clear pin enabled
#FUSES PUT //Power Up Timer
#FUSES NOBROWNOUT //No brownout reset
#FUSES IESO //Internal External Switch Over mode enabled
#FUSES FCMEN //Fail-safe clock monitor enabled

#use delay(clock=4000000)

//#bit led = GPIO.2
#bit ledr = GPIO.5
#use rs232(baud=9600,parity=N,xmit=PIN_A4,bits=8)
data ()
{

int dato;
while (1)
{
dato = read_adc();
printf ("valor %2X ", dato);

if (dato < 0)

ledr = 1;
delay_ms(500);
}
}


void main()
{

setup_adc_ports(sAN2|VSS_VDD);
setup_adc(ADC_CLOCK_INTERNAL);
set_adc_channel(0);
delay_us(100);

setup_timer_0(RTCC_INTERNAL|RTCC_DIV_1);
setup_timer_1(T1_DISABLED);
setup_timer_2(T2_DISABLED,0,1);
setup_comparator(NC_NC);
setup_vref(FALSE);
setup_oscillator(OSC_4MHZ);

//Funciones Personales

GPIO= 0b000000; TRISIO= 0b001100;
ledr = 1 ;

data ();

}

Thanks guys a lot...

[PCM programmer]

One obvious problem is that you have configured the A/D port so that
pin AN2 is the analog input pin, but then you have selected channel 0
for the A/D conversion. They have to be the same. You need to
change it so that both lines are setup for channel 0, or both for channel 2.

[javi.ar]

[Humberto]

You defined the variable dato as an unsigned integer, its permissible range is 0-255.

[javi.ar]

Thanks Humberto... very kind ...
I´ll try it later, and let everybody know if it worked...

Saludos (Soy de Buenos Aires)

[javi.ar]