ADC problems MSP430FG4618

cjpascal88

Other Parts Discussed in Thread: MSP430FG4618

Hello

I'm trying to use only the A15 ADC channel usign the MSP430FG4618 but I'm not getting to make it work, I hope you guys can help me configure correctly to have this done.

My ADC configuration is attached.

Best Regards,

Pascal.

Fullscreen 5226.questionADC.txt Download

#include "msp430fg4618.h"

void ADC_init(void);
void Clock_init(void);

unsigned int sample;

void main (void){

    WDTCTL = WDTPW | WDTHOLD; 

    ADC_init();
    
    for(;;){
        ADC12CTL0 |= ADC12SC;                   // Start conversions
   	while (!(ADC12IFG & 0x8000));           // Conversion done?
    	sample = ADC12MEM15;
    }

}

void ADC_init(void){

unsigned int i;
	
   	/* Configure ADC12 */
	P10SEL |= BIT6;                         // Enable A/D channel A0
    	ADC12CTL0 &= ~ENC;                      // Enable conversions

    	ADC12CTL0 = ADC12ON + SHT1_2 + REFON + REF2_5V;
    	ADC12CTL1 = SHS_0 + CONSEQ_2 + CSTARTADD_15;           

	ADC12MCTL15 = INCH_15 + SREF_1;
    
	for (i = 0x3600; i; i--);               // Delay for needed ref start-up.
                                            	// See datasheet for details.
    
   	ADC12CTL0 |= ENC;                       // Enable the ADC   

}

void Clock_init(void){

   /*
   Set System Clock Frequency to (121+1) * 32786 * 2 = 7.995392Mhz
   This freq. allows for 2400 - 230400 bit rate UART operation with less than 0.86% error
   */
   FLL_CTL0 = (DCOPLUS | XCAP14PF);       //Enable Frequency Multiplier (DCO+) and XIN/XOUT caps to 14pF
   SCFI0 = (FLLD_2 | FN_8);               //Set Multiplier to 2, and DCO range to 8MHz nominal
   SCFQCTL = 121;                         //7.995392Mhz Operation with No Modulation

    // Loop until 32kHz crystal stabilizes
    do
    {
      IFG1 &= ~OFIFG;                       // Clear oscillator fault flag
	  _delay_cycles(50000);
    }
    while (IFG1 & OFIFG);                   // Test osc fault flag	

}

over 14 years ago

0 BrandonAzbell over 14 years ago

TI__Guru 64840 points

Are you able to get any of the examples to work for the MSP430FG4618 just to verify basic functionality?

0 cjpascal88 over 14 years ago in reply to BrandonAzbell

Intellectual 715 points

Yes! But those are configured to channel A0 and MEM0, so when I try to change to A15 is not working...

Why am I want that? This is because I'm using P10.6 and I want it as an ADC.

Best Regards,

Pascal.

0 BrandonAzbell over 14 years ago in reply to cjpascal88

TI__Guru 64840 points

Pascal Hernandez said:

Yes! But those are configured to channel A0 and MEM0, so when I try to change to A15 is not working...

I realize this. I just wanted to make sure that you are able to get the examples working with the ADC properly performing conversions. Now we need to migrate to your desired channel A15 on P10.6.

As an experiment, would you modify one of the examples from A0 to target A15? You can use ADC12MCTL0 and ADC12MEM0 and assign it to channel A15. I would suggest converting the code example msp430xG46x_adc12_07.c to target A15.

See if this generates the results you desire and then you can tailor your code accordingly.

#include "msp430xG46x.h"

volatile unsigned int Results[8];
unsigned int Index;

void main(void)
{
WDTCTL = WDTPW + WDTHOLD;                         // Stop watchdog timer
P10SEL |= 0x01;                                                           // Enable A/D channel A15 pin
ADC12CTL0 = ADC12ON + SHT0_8 + MSC;       // Turn on ADC12, set sampling time
ADC12CTL1 = SHP + CONSEQ_2;                        // Use sampling timer, set mode
ADC12IE = 0x01;                                                        // Enable ADC12IFG.0
  ADC12MCTL0 = INCH_15 + SREF_1;                  // Setup ADC12MCTL0 to convert channel A15 and use Vref+, AVss
ADC12CTL0 |= ENC;                                                // Enable conversions
__enable_interrupt();                                               // Enable interrupts
ADC12CTL0 |= ADC12SC;                                      // Start conversion
__bis_SR_register(LPM0_bits);                            // LPM0
}

#pragma vector = ADC12_VECTOR
__interrupt void ADC12_ISR(void)
{
Results[Index++] = ADC12MEM0;                         // Move result, IFG is cleared
Index &= 0x07;                                                         // Modulo pointer
__no_operation();                                                   // SET BREAKPOINT HERE
}

0 cjpascal88 over 14 years ago in reply to BrandonAzbell

Intellectual 715 points

Hello,

Thanks for your help! I made it in a different way (because I can not use interrupts) and this was the results.

Fullscreen 7633.ADCquestionResolved.txt Download

#include "msp430xG46x.h"

volatile unsigned int i;

void main(void)
{
  WDTCTL = WDTPW + WDTHOLD;                 // Stop watchdog
 
  	ADC12CTL0 &= ~ENC;                     	// Disable Conversions    
  
  	ADC12CTL0 = REFON + REF2_5V + ADC12ON + SHT0_2 + MSC;
                                            // turn on 2.5V ref, set samp time
                                            // Multiple sample and conversion
  	ADC12CTL1 = SHP + CONSEQ_3;             // Use sampling timer
  											// Sequence of channels
  	ADC12MCTL0 = SREF_1 + INCH_1;           // Vr+=Vref+
  											// Input Channel A1 = OA0
  											// FINAL ANALOG OUTPUT
 	ADC12MCTL1 = SREF_1 + INCH_3;     		// Vr+=Vref+
  											// Input Channel A3 = OA1 
  											// TRANSIMPEDANCE OUTPUT  											
 	ADC12MCTL2 = SREF_1 + INCH_15 + EOS;     // Vr+=Vref+
  											// Input Channel A3 = OA1 
  											// Battery Input

  	_delay_cycles(3600);					// Delay for needed ref start-up.
                                            // See datasheet for details.
							                
  	ADC12CTL0 |= ENC;                       // Enable conversions
 	ADC12CTL0 |= ADC12SC;                   // Start conversions


  while (1)
  {
    ADC12CTL0 |= ADC12SC;                   // Start conversions
    while (!(ADC12IFG & 0x8003));           // Conversion done?
    ADC12MEM1;                              // Access result
    ADC12MEM2;                              // Access result
    ADC12MEM3;                              // Access result
    __no_operation();                       // SET BREAKPOINT HERE
  }
}

Best Regards,

Pascal.

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ADC problems MSP430FG4618