PIC18F1230 ADC problem - the ADC is not working.

[eem2am]

adcon2bits.acqt2 adc

hello,


I would be very grateful for help with my ADC problem.

I am using PIC18F1230 with C18 C compiler.

However, the ADC is not working.

My code is simple .....it just reads the AN0 voltage in a loop, then lights an LED on RB1 if Volts > 1 Volt but turns it off if voltage < 1 Volt.

Here is my code...

//Program to light LED if ADC
//input is > 1V
//Turns LED off if ADC input
//is < 1V

//ADREF is 5V

//PIC18F1230
//Compiler = Microchip C18 v3.22
//MPLAB v8.10


#include <p18f1230.h>
#include <adc.h>
#include <portb.h>

#pragma config OSC = INTIO2
#pragma config IESO = OFF
#pragma config PWRT = OFF
#pragma config BOR = OFF
#pragma config WDT = OFF
#pragma config MCLRE = OFF
#pragma config DEBUG = OFF
#pragma config CP0 = OFF
#pragma config CP1 = OFF
#pragma config CPB = OFF
#pragma config CPD = OFF
#pragma config WRT0 = OFF
#pragma config WRT1 = OFF
#pragma config WRTB = OFF
#pragma config WRTC = OFF
#pragma config WRTD = OFF


unsigned char m,n,c,ADRESL_1,ADRESH_1;
volatile unsigned conversion_val;

void main(void) {

//Set up ports
PORTB = 0x00;

//----------------------------------------
//Set up OSCTUNE
//Disable PLL
OSCTUNEbits.PLLEN = 0;

//Set up OSCCON
//4MHZ
OSCCONbits.IRCF2 = 1;
OSCCONbits.IRCF1 = 1;
OSCCONbits.IRCF0 = 0;
//Internal oscillator block
OSCCONbits.SCS1 = 1;
OSCCONbits.SCS1 = 0;
//----------------------------------------

//Set up port direction
//AN0 is analog input (0-5V)
TRISA = 0x01;
TRISB = 0x00;

//----------------------
//Disable PWM
//$$ PWM time base timer disable $$
PTCON1bits.PTEN = 0;
//SET UP pwm control register 0
//PWM disabled...pins GPIO
PWMCON0bits.PWMEN2 = 0;
PWMCON0bits.PWMEN1 = 0;
PWMCON0bits.PWMEN0 = 0;
//----------------------

//----------------------
//Disable the comparator
CMCONbits.CMEN2 = 0;
CMCONbits.CMEN1 = 0;
CMCONbits.CMEN0 = 0;
CVRCONbits.CVREN = 0;
//----------------------

// ------------------------------------------
// SET-UP ADC:-
//Set-Up ADCON0bits

//disable the special event trigger from PWM
ADCON0bits.SEVTEN = 0;
//ADC MODULE IS DISABLED
ADCON0bits.ADON = 0;

//Set-up ADCON1bits
//+ve ref for AD is AVDD
ADCON1bits.VCFG0 = 0;
//RA6
ADCON1bits.PCFG3 = 0;
//RA4
ADCON1bits.PCFG2 = 0;
//RA1
ADCON1bits.PCFG1 = 0;
//AN0
ADCON1bits.PCFG0 = 1;


//Set-up ADCON2bits
//Right justify
ADCON2bits.ADFM = 1;
//20 TAD = AD acquisition time
ADCON2bits.ACQT2 = 1;
ADCON2bits.ACQT1 = 1;
ADCON2bits.ACQT0 = 1;
//AD conversion clk select bits = Fosc/64
ADCON2bits.ADCS2 = 1;
ADCON2bits.ADCS1 = 1;
ADCON2bits.ADCS0 = 0;
//^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
//Channel 0 = AN0
ADCON0bits.CHS1 = 0;
ADCON0bits.CHS0 = 0;
//ADC MODULE IS ENABLED
ADCON0bits.ADON = 1;

//DISABLE INTERRUPTS
INTCONbits.GIE = 0;
PIE1bits.ADIE = 0;

// *** THIS IS A LOOP WHERE AD CONVERSIONS ARE DONE. ***
for(; {
//Acquisition time wait
for(m=0;m<55;m++) {;}

//clear conversion value
conversion_val = 0x0000;

//Start AD Conversion
ADCON0bits.GO = 1;


while (ADCON0bits.GO) {;}


//Clear AD flag
PIR1bits.ADIF = 0;

//Load up temporary Conversion value holders
ADRESL_1 = ADRESL;
ADRESH_1 = ADRESH;

//Load up conversion_val from ADRESH_1 & ADRESL_1
if (ADRESL_1 & 0x01) {(conversion_val = (conversion_val | 0x0001));}
if (ADRESL_1 & 0x02) {(conversion_val = (conversion_val | 0x0002));}
if (ADRESL_1 & 0x04) {(conversion_val = (conversion_val | 0x0004));}
if (ADRESL_1 & 0x08) {(conversion_val = (conversion_val | 0x0008));}

if (ADRESL_1 & 0x10) {(conversion_val = (conversion_val | 0x0010));}
if (ADRESL_1 & 0x20) {(conversion_val = (conversion_val | 0x0020));}
if (ADRESL_1 & 0x40) {(conversion_val = (conversion_val | 0x0040));}
if (ADRESL_1 & 0x80) {(conversion_val = (conversion_val | 0x0080));}

if (ADRESH_1 & 0x01) {(conversion_val = (conversion_val | 0x0100));}
if (ADRESH_1 & 0x02) {(conversion_val = (conversion_val | 0x0200));}

//...conversion_val is now loaded.
//...zero out the 6 MSB's...
conversion_val = conversion_val & 0x03FF;

//Light LED on RB1 if AD input was > 1 V
if (conversion_val > 0x00CC) {LATBbits.LATB1 = 1;}

//Extinguish LED on RB1 if AD input was < 1V
if (conversion_val < 0x00CC) {LATBbits.LATB1 = 0;}


}
// *** END OF ADC LOOP ****
return;
}
// *** END OF MAIN ***



.......................................................................................................
here is my cct diagram..

many thanks for your reading.

Added after 3 minutes:

hello, sorry that face somehow appeared in my code, i don't know why.

that bit is just the two semi-colons to get the loop going in which the ADC happens.

code was
for (; {

(i hope the face did not appear again)

Added after 43 seconds:

sorry again, i guess this PC is set up to make two semi-colons appear as a face.