ref_ex1_internalReference.c

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 * Copyright (c) 2017, Texas Instruments Incorporated
 * All rights reserved.
 *
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 *    notice, this list of conditions and the following disclaimer.
 *
 * *  Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
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 *    its contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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#include "driverlib.h"
 
//******************************************************************************
//******************************************************************************
 
#define TIMER_PERIOD 80
 
void main (void)
{
    //Stop Watchdog Timer
    WDT_A_hold(WDT_A_BASE);
 
    //Set P1.1 as an input pin.
    /*
 
     * Select Port 1
     * Set Pin 1 as input
     * Set Ternary module function
     */
    GPIO_setAsPeripheralModuleFunctionInputPin(
            GPIO_PORT_P1,
            GPIO_PIN1,
            GPIO_TERNARY_MODULE_FUNCTION);
 
    //Set P1.0 as an output pin.
    /*
 
     * Select Port 1
     * Set Pin 0 as output
     */
    GPIO_setAsOutputPin(
            GPIO_PORT_P1,
            GPIO_PIN0);
 
 
    //Set P3.5 as an output pin.
    /*
 
     * Select Port 3
     * Set Pin 5 as output
     */
    GPIO_setAsOutputPin(
            GPIO_PORT_P3,
            GPIO_PIN5);
 
    //Initialize the ADC10 Module
    /*
     * Base Address for the ADC10 Module
     * Use internal ADC10 bit as sample/hold signal to start conversion
     * USE MODOSC 5MHZ Digital Oscillator as clock source
     * Use default clock divider of 1
     */
    ADC10_B_init(ADC10_B_BASE,
        ADC10_B_SAMPLEHOLDSOURCE_SC,
        ADC10_B_CLOCKSOURCE_ADC10OSC,
        ADC10_B_CLOCKDIVIDER_1);
 
    ADC10_B_enable(ADC10_B_BASE);
 
    /*
     * Base Address for the ADC10 Module
     * Sample/hold for 16 clock cycles
     * Do not enable Multiple Sampling
     */
    ADC10_B_setupSamplingTimer(ADC10_B_BASE,
        ADC10_B_CYCLEHOLD_16_CYCLES,
        ADC10_B_MULTIPLESAMPLESDISABLE);
 
    //Configure Memory Buffer
    /*
     * Base Address for the ADC10 Module
     * Use input A1
     * Use positive reference of Internally generated Vref
     * Use negative reference of AVss
     */
    ADC10_B_configureMemory(ADC10_B_BASE,
        ADC10_B_INPUT_A1,
        ADC10_B_VREFPOS_INT,
        ADC10_B_VREFNEG_AVSS);
 
    ADC10_B_clearInterrupt(ADC10_B_BASE,
        ADC10IE0);
 
    //Enable Memory Buffer interrupt
    ADC10_B_enableInterrupt(ADC10_B_BASE,
        ADC10IE0);
 
    //Configure internal reference
    //If ref generator busy, WAIT
    while ( REF_BUSY == Ref_isRefGenBusy(REF_BASE) ) ;
 
    //Select internal ref = 1.5V
    Ref_setReferenceVoltage(REF_BASE,
        REF_VREF1_5V);
    //Internal Reference ON
    Ref_enableReferenceVoltage(REF_BASE);
 
    // Configure TA0 to provide delay for reference settling ~75us
    Timer_A_initUpModeParam param = {0};
    param.clockSource = TIMER_A_CLOCKSOURCE_SMCLK;
    param.clockSourceDivider = TIMER_A_CLOCKSOURCE_DIVIDER_1;
    param.timerPeriod = TIMER_PERIOD;
    param.timerInterruptEnable_TAIE = TIMER_A_TAIE_INTERRUPT_DISABLE;
    param.captureCompareInterruptEnable_CCR0_CCIE =
        TIMER_A_CAPTURECOMPARE_INTERRUPT_ENABLE;
    param.timerClear = TIMER_A_DO_CLEAR;
    param.startTimer = true;
    Timer_A_initUpMode(TIMER_A0_BASE, &param);
 
    __bis_SR_register(CPUOFF + GIE);           // LPM0, TA0_ISR will force exit
 
 
 
    for (;;)
    {
        //Delay between conversions
        __delay_cycles(5000);
 
        //Enable and Start the conversion
        //in Single-Channel, Single Conversion Mode
        ADC10_B_startConversion(ADC10_B_BASE,
            ADC10_B_SINGLECHANNEL);
 
        //LPM0, ADC10_ISR will force exit
        __bis_SR_register(CPUOFF + GIE);
        //For debug only
        __no_operation();
 
 
    }
}
 
//ADC10 interrupt service routine
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector=ADC10_VECTOR
__interrupt
#elif defined(__GNUC__)
__attribute__((interrupt(ADC10_VECTOR)))
#endif
void ADC10_ISR (void)
{
    switch (__even_in_range(ADC10IV,12)){
        case  0: break; //No interrupt
        case  2: break; //conversion result overflow
        case  4: break; //conversion time overflow
        case  6: break; //ADC10HI
        case  8: break; //ADC10LO
        case 10: break; //ADC10IN
        case 12:        //ADC10IFG0
 
            //Automatically clears ADC10IFG0 by reading memory buffer
        //ADC10MEM = A0 > 0.5V?
            if (ADC10_B_getResults(ADC10_B_BASE) < 0x155){
                //Clear P1.0 LED off
                /*
 
                * Select Port 1
                * Set Pin 0 to output Low.
                */
                GPIO_setOutputLowOnPin(
                    GPIO_PORT_P1,
                    GPIO_PIN0
                );
 
                //Clear P3.5 LED off
                /*
 
                * Select Port 3
                * Set Pin 5 to output Low.
                */
                GPIO_setOutputLowOnPin(
                    GPIO_PORT_P3,
                    GPIO_PIN5
                );
 
            } else   {
                //Set P1.0 LED on
                /*
 
                * Select Port 1
                * Set Pin 0 to output high.
                */
                GPIO_setOutputHighOnPin(
                    GPIO_PORT_P1,
                    GPIO_PIN0
                );
 
                //Set P3.5 LED on
                /*
 
                * Select Port 3
                * Set Pin 5 to output high.
                */
                GPIO_setOutputHighOnPin(
                    GPIO_PORT_P3,
                    GPIO_PIN5
                );
            }
 
            //Clear CPUOFF bit from 0(SR)
            //Breakpoint here and watch ADC_Result
            __bic_SR_register_on_exit(CPUOFF);
            break;
        default: break;
    }
}
 
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector=TIMER0_A0_VECTOR
__interrupt
#elif defined(__GNUC__)
__attribute__((interrupt(TIMER0_A0_VECTOR)))
#endif
void TA0_ISR (void)
{
      TA0CTL = 0;
      LPM0_EXIT;                                // Exit LPM0 on return
}