CCS/MSP430FR2433: Having difficulty reading temp sensor using ADC as part of larger program

Which parts did you adopt?

adc10_16 does the ADCSC in a timer; how are you starting it now?

I suppose you got rid of the "LPM forever" statement; what did you replace it with?

Are you still starting up the Reference Generator (including TSENSOREN)?

All parts were adopted for my code with exception to the timer. The enable and start conversion bits are set immediately following the reference settling. That should answer the second question as well. LPM forever is simply non-existent. I want to collect the temperature value and then move on with the program. Reference generator is being started including TSENSOREN.

The overall structure of the code is to run initializers on startup (including ADC initialization), go into LPM3 mode waiting for an interrupt over P2.4. Once an interrupt is received, the MSP430 waits for SPI commands to tell it what to do next. Reading temperature is one of these commands. Below is the initialization code, the read temperature code, and the ADC interrupt.

void InitializeADC(void){
    // Configure ADC10
    ADCCTL0 |= ADCSHT_2 | ADCON;                             // ADCON, S&H=16 ADC clks
    ADCCTL1 |= ADCSHP;                                       // ADCCLK = MODOSC; sampling timer
    ADCCTL2 |= ADCRES;                                       // 10-bit conversion results
}

int Temperature(void)
{
    ADCCTL0 &= ~(ADCSHT_2|ADCON); //initial setting off

    ADCCTL0 |= ADCSHT_8 | ADCON;                                    //  ADC ON, 64 ADCCLK cycles per sample
    ADCCTL1 |= ADCSHP;                                              //  sampling timer (already set)
    ADCCTL2 |= ADCRES;                                              //  10-bit conversion results (already set)
    ADCMCTL0 |= ADCSREF_1 | ADCINCH_12;                             //  A12 --> Temperature Sensor
    ADCIE |=ADCIE0;                                                 //  Enable the Interrupt

    // Configure reference and temp sensor
    PMMCTL0_H = PMMPW_H;                                            //  Unlock the PMM registers

    PMMCTL2 |= TSENSOREN;
    if (referenceV==1){
        PMMCTL2 |= INTREFEN;                                        //  Enable reference and temperature sensor
        __delay_cycles(400);                                        //  Delay for reference settling
    }

    ADCCTL0 |= ADCENC | ADCSC;                                      //  Sampling and ADC conversion begin
    __bis_SR_register(LPM0_bits | GIE);                             //  LPM0 with interrupts enabled (uses interrupt defined in ADC section)

    ADCCTL0 &= ~(ADCENC | ADCSC);                                    //  returned from interrupt,turn off ADC
    ADCIE &= ~ADCIE0;                                               //  disable ADC interrupt
    ADCMCTL0 &= ~ADCINCH_12;                                        //  A122 ADC input unselected

    //reseting initial settings
    ADCCTL0 &= ~ADCSHT_8;
    ADCCTL0 |= ADCSHT_2;
    ADCMCTL0 &= ~ADCSREF_1; //reference voltage

    //turn off reference
    PMMCTL2 &= ~(TSENSOREN);
    if (referenceV==1){
        PMMCTL2 &= ~(INTREFEN);                                //  disable reference and temperature sensor
        __delay_cycles(400);                                               //  Delay for reference settling
    }
    PMMCTL0_H &= ~PMMPW_H;                                             //  Lock the PMM registers

    int Cal30C = CALADC_15V_30C;
    int Cal85C = CALADC_15V_30C;
    //int value = (ADC_Result-CALADC_15V_30C)*(85-30)/(CALADC_15V_85C-CALADC_15V_30C)+30;
    int value = (ADC_Result-Cal30C)*(85-30)/(Cal85C-Cal30C)+30;
    return value;
}

// ADC interrupt service routine
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector=ADC_VECTOR
__interrupt void ADC_ISR(void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(ADC_VECTOR))) ADC_ISR (void)
#else
#error Compiler not supported!
#endif
{
        switch(__even_in_range(ADCIV,ADCIV_ADCIFG))
            {
                case ADCIV_NONE:
                    break;
                case ADCIV_ADCOVIFG:
                    break;
                case ADCIV_ADCTOVIFG:
                    break;
                case ADCIV_ADCHIIFG:
                    break;
                case ADCIV_ADCLOIFG:
                    break;
                case ADCIV_ADCINIFG:
                    break;
                case ADCIV_ADCIFG:                                         //   Our Case
                    ADC_Result = ADCMEM0;
                    __bic_SR_register_on_exit(LPM0_bits);            //   Clear CPUOFF bit from LPM0
                    break;
                default:
                    break;
    }
}

 

Hi Mitch,

No issues. I somehow missed Bruce's answer above. I discovered the same typo he found and it has been performing fine since. I've marked his answer above as resolving the issue.

Donald