Problem with Multiple ADC channels

[pandu.ranganadh]

Hi to all,

I am using the bellow details of version.

CCS C Compiller 6.0
PCM version 3.170b
PCH version 3.170b
IDE version 3.36

MPLAB IDE version v8.02

I have a problem with accessing multiple ADC Channels in PIC16F877,
and i am using PIC older version demo board.

http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1406&dDocName=en010072&part=DM163022


#include <16F877.H>
#device adc=10
//#fuses XT, NOWDT, NOPROTECT, BROWNOUT, PUT, NOLVP
#use delay(clock=16000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7, ERRORS)

#include "flex_lcd.c"

//============================
void main()
{
int16 adc_value;
float volts,a=10.25;

lcd_init();


setup_adc_ports(RA0_ANALOG);
setup_adc(ADC_CLOCK_INTERNAL);
set_adc_channel(0);
//set_adc_channel(1);
delay_us(20);


while(1)
{
adc_value = read_adc();

/***************************************************************************/
/* The formula for ADC conversion is */
/* ADC result = (ADC Digital output value * V.reff)/2^no.of ADC channels */
/* -> 1023.0 or 1024.0 represents the 10 bit ADC, inorder to get acurate */
/* result that value should be maintain as float. */
/* -> 5 represents the V reference voltage for ADC is 5V */
/* -> " adc_value " represents the o/p of the ADC, inetially is was binary */
/* but " read_adc(); " function converts that value in to integer. */
/* -> Inoder ot get float result answer should be convert(Typecast) in to */
/* float. */
/***************************************************************************/

volts = (float)(adc_value * 5)/1023.0; // This is the fixed formula

//lcd_putc("\f Output \n");

printf(lcd_putc,"\f %3.4f Volts\n",volts);


delay_ms(500);

}


}

Its working for Channel-0 only. How to use remaining channels.
Please check and resend code.

Bye
Thanking you.

[densimitre]

setup_adc_ports (other ports)

Bye

[pandu.ranganadh]

Hi,

Thank you for sending reply,
I have done that job as

setup_adc_ports(ALL_ANALOG); or any of other, then its not working, There is no display on LCD.


Bye
Thanking you.

[densimitre]

First set_adc_channel, then read_adc()

to read other channel you mut set the correct channel and read it after..

Bye

[PCM programmer]