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MSP430FR5987: ADC12B Interrupt

Part Number: MSP430FR5987

I have initialized the ADC12B on the MSP430fr5987 but can not get it to generate and interrupt??? Single conversion triggered of ADC12ENC.

P9SEL0 |= BIT2;                    //Set P9.2 as Analog Input, A10
     P9SEL1 |= BIT2;

    ADC12CTL0 = ADC12ON;           // ADC12ENC = 0 , ADC12SC=0

     // REF_A SLAU367L p.668
     while(REFCTL0 & REFGENBUSY);     // If ref generator busy, WAIT
     REFCTL0 |= REFVSEL_1+REFON;      // Select internal ref = 2.0V

     // Sample & Hold Time use 16 sample clocks for MEM0 thru MEM32
     ADC12CTL0 |= 0x2200;             //  ADC_SMP_16;

     // use MOD Clock
     ADC12CTL1 |= 0x18;  //TODO Try SMCLK  ADC_CLK_MOD;

     // single channel single conversion
     ADC12CTL1 |= 0x0;                // ADC_SNGL;

     // Invert single sample and hold
     ADC12CTL1|= 0;                   // no invert

      // use 12 bit resolution
     ADC12CTL2 |= 0x0020;             // ADC_12_BIT;

     // VR+ = VREF buffered (2.0V), VR- = AVSS (0V)
     ADC12MCTL0 |= 0x0100;            // ADC_REF_VRF;

     //INCHx = 10  (A10 or DAC VOUTB)
     ADC12MCTL0 |= 0x000A;            // 10;

     ADC12IFGR0 = 0x0000;                  // clear the interrupt flag
     ADC12IFGR1 = 0x0000;
     ADC12IFGR2 = 0x0000;

     ADC12IER0 = ADC12IE0;           // Enable interrupt for ADC12MEM0
     ADC12IER1 =0;                   // Disable interrupts for MEM16 thru MEM31
     ADC12IER2 =0;                   // Disable interrupts for aux inputs

     ADC12CTL0 |= 0x0003;              // ADCSC = On,ADCENC= On

---------------------------------------------------------------------------------------------------------------------

#pragma vector=ADC12_VECTOR
__interrupt void ADC12 (void)
{

   __disable_interrupt();                // disable any more interrupts
    
   ADC12CTL0 &= 0xfffc;                     // ADC12ENC =0, ADC12SC =0

//switch(__even_in_range(ADC12IV, ADC12IV_ADC12RDYIFG))
//  {
// case ADC12IV_NONE:        break;        // Vector  0:  No interrupt
// case ADC12IV_ADC12OVIFG:  break;        // Vector  2:  ADC12MEMx Overflow
// case ADC12IV_ADC12TOVIFG: break;        // Vector  4:  Conversion time overflow
// case ADC12IV_ADC12HIIFG:  break;        // Is A1 > 2V?: High Interrupt
// case ADC12IV_ADC12LOIFG:  break;        // Is A1 < 1V?: Low Interrupt
// case ADC12IV_ADC12INIFG:  break;        // Vector 10:  ADC12IN
// case ADC12IV_ADC12IFG0:
//
//      break;        // Vector 12:  ADC12MEM0
//
//
// case ADC12IV_ADC12IFG1:   break;        // Vector 14:  ADC12MEM1
// case ADC12IV_ADC12IFG2:   break;        // Vector 16:  ADC12MEM2
// case ADC12IV_ADC12IFG3:

      ADC_Capture_Data(adc_rslt);

//     break;        // Vector 18:  ADC12MEM3
// case ADC12IV_ADC12IFG4:   break;        // Vector 20:  ADC12MEM4
// case ADC12IV_ADC12IFG5:   break;        // Vector 22:  ADC12MEM5
// case ADC12IV_ADC12IFG6:   break;        // Vector 24:  ADC12MEM6
// case ADC12IV_ADC12IFG7:   break;        // Vector 26:  ADC12MEM7
// case ADC12IV_ADC12IFG8:   break;        // Vector 28:  ADC12MEM8
// case ADC12IV_ADC12IFG9:   break;        // Vector 30:  ADC12MEM9
// case ADC12IV_ADC12IFG10:  break;        // Vector 32:  ADC12MEM10
// case ADC12IV_ADC12IFG11:  break;        // Vector 34:  ADC12MEM11
// case ADC12IV_ADC12IFG12:  break;        // Vector 36:  ADC12MEM12
// case ADC12IV_ADC12IFG13:  break;        // Vector 38:  ADC12MEM13
// case ADC12IV_ADC12IFG14:  break;        // Vector 40:  ADC12MEM14
// case ADC12IV_ADC12IFG15:  break;        // Vector 42:  ADC12MEM15
// case ADC12IV_ADC12IFG16:  break;        // Vector 44:  ADC12MEM16
// case ADC12IV_ADC12IFG17:  break;        // Vector 46:  ADC12MEM17
// case ADC12IV_ADC12IFG18:  break;        // Vector 48:  ADC12MEM18
// case ADC12IV_ADC12IFG19:  break;        // Vector 50:  ADC12MEM19
// case ADC12IV_ADC12IFG20:  break;        // Vector 52:  ADC12MEM20
// case ADC12IV_ADC12IFG21:  break;        // Vector 54:  ADC12MEM21
// case ADC12IV_ADC12IFG22:  break;        // Vector 56:  ADC12MEM22
// case ADC12IV_ADC12IFG23:  break;        // Vector 58:  ADC12MEM23
// case ADC12IV_ADC12IFG24:  break;        // Vector 60:  ADC12MEM24
// case ADC12IV_ADC12IFG25:  break;        // Vector 62:  ADC12MEM25
// case ADC12IV_ADC12IFG26:  break;        // Vector 64:  ADC12MEM26
// case ADC12IV_ADC12IFG27:  break;        // Vector 66:  ADC12MEM27
// case ADC12IV_ADC12IFG28:  break;        // Vector 68:  ADC12MEM28
// case ADC12IV_ADC12IFG29:  break;        // Vector 70:  ADC12MEM29
// case ADC12IV_ADC12IFG30:  break;        // Vector 72:  ADC12MEM30
// case ADC12IV_ADC12IFG31:  break;        // Vector 74:  ADC12MEM31
// case ADC12IV_ADC12RDYIFG: break;        // Vector 76:  ADC12RDY
// default: break;
//  }

      ADC12IFGR0 = 0x0000;                  // clear the interrupt flag
      ADC12IFGR1 = 0x0000;
      ADC12IFGR2 = 0x0000;
 
 __enable_interrupt();                   // re-enable interrupts

 ADC12CTL0 |= ADC12ENC | ADC12SC;        // Start sampling/conversion

}
------------------------------------------------------------------

 void ADC_Capture_Data(unsigned int *data)
 {

      data[0] = 1;

      data[1] =  ADC12MEM0;
      data[2] =  ADC12MEM1;
      data[3] =  ADC12MEM2;
      data[4] =  ADC12MEM3;
}

  • Hi Gary,
    There is a piece of example code that covers this called adc12_02. All you should need to do is change the channel assignment.
  • Here is the code, to make it easier for you:

    #include <msp430.h>
    
    int main(void)
    {
      WDTCTL = WDTPW | WDTHOLD;                 // Stop WDT
    
      // GPIO Setup
      P1OUT &= ~BIT0;                           // Clear LED to start
      P1DIR |= BIT0;                            // P1.0 output
      P1SEL1 |= BIT1;                           // Configure P1.1 for ADC
      P1SEL0 |= BIT1;
    
      // Disable the GPIO power-on default high-impedance mode to activate
      // previously configured port settings
      PM5CTL0 &= ~LOCKLPM5;
    
      // By default, REFMSTR=1 => REFCTL is used to configure the internal reference
      while(REFCTL0 & REFGENBUSY);              // If ref generator busy, WAIT
      REFCTL0 |= REFVSEL_0 | REFON;             // Select internal ref = 1.2V
                                                // Internal Reference ON
    
      // Configure ADC12
      ADC12CTL0 = ADC12SHT0_2 | ADC12ON;
      ADC12CTL1 = ADC12SHP;                     // ADCCLK = MODOSC; sampling timer
      ADC12CTL2 |= ADC12RES_2;                  // 12-bit conversion results
      ADC12IER0 |= ADC12IE0;                    // Enable ADC conv complete interrupt
      ADC12MCTL0 |= ADC12INCH_1 | ADC12VRSEL_1; // A1 ADC input select; Vref=1.2V
    
      while(!(REFCTL0 & REFGENRDY));            // Wait for reference generator
                                                // to settle
    
      while(1)
      {
        __delay_cycles(5000);                    // Delay between conversions
        ADC12CTL0 |= ADC12ENC | ADC12SC;         // Sampling and conversion start
    
        __bis_SR_register(LPM0_bits + GIE);      // LPM0, ADC10_ISR will force exit
        __no_operation();                        // For debug only
      }
    }
    
    #if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
    #pragma vector = ADC12_VECTOR
    __interrupt void ADC12_ISR(void)
    #elif defined(__GNUC__)
    void __attribute__ ((interrupt(ADC12_VECTOR))) ADC12_ISR (void)
    #else
    #error Compiler not supported!
    #endif
    {
      switch (__even_in_range(ADC12IV, ADC12IV_ADC12RDYIFG))
      {
        case ADC12IV_NONE:        break;        // Vector  0:  No interrupt
        case ADC12IV_ADC12OVIFG:  break;        // Vector  2:  ADC12MEMx Overflow
        case ADC12IV_ADC12TOVIFG: break;        // Vector  4:  Conversion time overflow
        case ADC12IV_ADC12HIIFG:  break;        // Vector  6:  ADC12BHI
        case ADC12IV_ADC12LOIFG:  break;        // Vector  8:  ADC12BLO
        case ADC12IV_ADC12INIFG:  break;        // Vector 10:  ADC12BIN
        case ADC12IV_ADC12IFG0:                 // Vector 12:  ADC12MEM0 Interrupt
          if (ADC12MEM0 >= 0x6B4)               // ADC12MEM = A1 > 0.5V?
            P1OUT |= BIT0;                      // P1.0 = 1
          else
            P1OUT &= ~BIT0;                     // P1.0 = 0
            __bic_SR_register_on_exit(LPM0_bits); // Exit active CPU
          break;                                // Clear CPUOFF bit from 0(SR)
    
        case ADC12IV_ADC12IFG1:   break;        // Vector 14:  ADC12MEM1
        case ADC12IV_ADC12IFG2:   break;        // Vector 16:  ADC12MEM2
        case ADC12IV_ADC12IFG3:   break;        // Vector 18:  ADC12MEM3
        case ADC12IV_ADC12IFG4:   break;        // Vector 20:  ADC12MEM4
        case ADC12IV_ADC12IFG5:   break;        // Vector 22:  ADC12MEM5
        case ADC12IV_ADC12IFG6:   break;        // Vector 24:  ADC12MEM6
        case ADC12IV_ADC12IFG7:   break;        // Vector 26:  ADC12MEM7
        case ADC12IV_ADC12IFG8:   break;        // Vector 28:  ADC12MEM8
        case ADC12IV_ADC12IFG9:   break;        // Vector 30:  ADC12MEM9
        case ADC12IV_ADC12IFG10:  break;        // Vector 32:  ADC12MEM10
        case ADC12IV_ADC12IFG11:  break;        // Vector 34:  ADC12MEM11
        case ADC12IV_ADC12IFG12:  break;        // Vector 36:  ADC12MEM12
        case ADC12IV_ADC12IFG13:  break;        // Vector 38:  ADC12MEM13
        case ADC12IV_ADC12IFG14:  break;        // Vector 40:  ADC12MEM14
        case ADC12IV_ADC12IFG15:  break;        // Vector 42:  ADC12MEM15
        case ADC12IV_ADC12IFG16:  break;        // Vector 44:  ADC12MEM16
        case ADC12IV_ADC12IFG17:  break;        // Vector 46:  ADC12MEM17
        case ADC12IV_ADC12IFG18:  break;        // Vector 48:  ADC12MEM18
        case ADC12IV_ADC12IFG19:  break;        // Vector 50:  ADC12MEM19
        case ADC12IV_ADC12IFG20:  break;        // Vector 52:  ADC12MEM20
        case ADC12IV_ADC12IFG21:  break;        // Vector 54:  ADC12MEM21
        case ADC12IV_ADC12IFG22:  break;        // Vector 56:  ADC12MEM22
        case ADC12IV_ADC12IFG23:  break;        // Vector 58:  ADC12MEM23
        case ADC12IV_ADC12IFG24:  break;        // Vector 60:  ADC12MEM24
        case ADC12IV_ADC12IFG25:  break;        // Vector 62:  ADC12MEM25
        case ADC12IV_ADC12IFG26:  break;        // Vector 64:  ADC12MEM26
        case ADC12IV_ADC12IFG27:  break;        // Vector 66:  ADC12MEM27
        case ADC12IV_ADC12IFG28:  break;        // Vector 68:  ADC12MEM28
        case ADC12IV_ADC12IFG29:  break;        // Vector 70:  ADC12MEM29
        case ADC12IV_ADC12IFG30:  break;        // Vector 72:  ADC12MEM30
        case ADC12IV_ADC12IFG31:  break;        // Vector 74:  ADC12MEM31
        case ADC12IV_ADC12RDYIFG: break;        // Vector 76:  ADC12RDY
        default: break;
      }
    }
    

    Try this and let me know if it does not work.

  • Thank you. The only difference I can see is that you turned on Sample and Hold Pulse mode (ADC12SHP). I was attempting to use ADC12ENC and ACD12SC to start the conversion. Figure 28-8 shows the "sample input channel defined in ADC12MCTLx"bubble starting the conversion without the rising edge of SAMPCON. I realize that I will need a sample and hold time to get a accurate reading but thought I could get the ADC working with out it. Apparently not. I guess I don't see what triggers SHI in Figure 28-3&4. So, I tried to figure it out using the supplied documentation, which typically I find to be excellent.
  • Happy to help. I'll take note of your feedback, but yes, the ADC can be tricky sometimes.

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