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ADC dsPIC please help

Electron_23

May 6, 2014
6
Joined
May 6, 2014
Messages
6
Hello everyone.

Im trying to use the ADC module of the dsPIC33ep512mu810, reading the potentiometer of the Explorar 16 board, and show the binary conversion in PORT A (LEDs). Up to now I did not have success and I don't know whats missing or wrong. Could someone help please?

//DEFINES or PARAMETERS
#define FOSC 8000000 //OSCILLATION FREQUENCY
#define PLL 1 //SETS PLL
#define FCY (FOSC*PLL/2) //CYCLE FREQUENCY



#include <stdio.h>
#include <stdlib.h>
#include <p33ep512mu810.h>

//MACROS or CONFIGURATION BITS
_FOSCSEL(FNOSC_PRI & IESO_OFF)
// Primary oscillator as source
// Start up with user-selected oscillator source
_FOSC(FCKSM_CSDCMD & POSCMD_XT & OSCIOFNC_ON)
// Both Clock switching and Fail-safe Clock Monitor are disabled
// XT Crystal Oscillator Mode
// OSC2 is general purpose digital I/O pin
_FWDT(FWDTEN_OFF)
// Watchdog timer enabled/disabled by user software
_FPOR(FPWRT_PWR16 & BOREN_ON)
// Power-on Reset Timer Value and bor enabled
_FGS(GWRP_OFF & GSS_OFF & GSSK_OFF)
// General Segment may be written
// General Segment Code protect is disabled
// General Segment Write Protection and Code Protection is Disabled


// FUNCTION DECLARATIONS
void adc(void);
void delay_ms(long ms);


/*
*
*/
int main() {
TRISA = 0;
adc();

//loop to sample and acquire data
while(1){
AD1CON1bits.SAMP = 1; //sampling
delay_ms(10); //sample time
AD1CON1bits.SAMP = 0; //holding

while(!AD1CON1bits.DONE); //is the conversion done?
PORTA = ADC1BUF1; //data is shown in port A (LEDs)
}

return (EXIT_SUCCESS);
}



void adc(void){

ANSELA = ANSELB = ANSELC = ANSELD = ANSELE = ANSELG = 0x0000;
// Set ports A, B, C, D, E, G as I/O digital ports.
ANSELBbits.ANSB5 = 1; //makes AN5/RB5 analog input.

AD1CON1bits.AD12B = 1; // Sets 12 bits ADC.

AD1CON1 = 0x0000;
AD1CON2 = 0x0000;
AD1CON3 = 0x000F;
AD1CON4 = 0x0000;
AD1CHS0 = 0x0005;
AD1CHS123 = 0x0000;
AD1CSSH = 0x0000;
AD1CSSL = 0x0000;
AD1CON1bits.ADON = 1; //enables ADC
delay_ms(10);
}



void delay_ms(long ms){

T1CON = 0; //reset timer
TMR1 = 0; //load timer count register to 0

IPC0bits.T1IP = 1; // interrupt priority count
PR1 = ((FCY/256)*ms)/1000; //20ms delay. Comes from (((Fosc/4)/prescaler)*20ms)/(1000ms)
IFS0bits.T1IF = 0;
IEC0bits.T1IE = 0;
T1CON = 0X8030; //hexadecimal of 1000000000110000
// which means start the timer and select 256 prescaler
while(IFS0bits.T1IF == 0);

}
 

shumifan50

Jan 16, 2014
579
Joined
Jan 16, 2014
Messages
579
Have you tried running this with a PicKit debugger to see that it is running through the logic as expected?
 

Electron_23

May 6, 2014
6
Joined
May 6, 2014
Messages
6
Have you tried running this with a PicKit debugger to see that it is running through the logic as expected?
Yes. I tried with the PicKit3 to load the code to the chip in a Explorer 16 Board. The LEDs shows one state, I rotate the potentiometer and the LEDs don't change.
 

shumifan50

Jan 16, 2014
579
Joined
Jan 16, 2014
Messages
579
I had a quick look at the datasheet and you should be able to step through the code, set breakpoints and interrupt execution from MPLAB using the PicKit3. This should help you to see if it is actually getting beyond your 'while(IFS0bits.T1IF == 0);' or whether it has not really started the conversion.
 
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