eee_scenario_x/main.c

/* DriverLib Includes */
#include <ti/devices/msp432p4xx/driverlib/driverlib.h>

/* Standard Includes */
#include <stdint.h>
#include <math.h>
#include <descrambler.h>

// Sampling frequency
const int fs = 48000;


// Timer for calculate sine wave
static double Timer = 0;
// Coefficients for bandstop filter
const double B1[] = {0.7755, -2.5985, 6.3671, -9.6188, 11.5650, -9.6188, 6.3671, -2.5985, 0.7755};
const double A1[] = {1.0000, -3.1835, 7.4065, -10.6464, 12.1861, -9.6677, 6.1083, -2.3849, 0.6809};
// Coefficients for lowpass filter
const double B2[] = {0.0000, 0.0001, 0.0005, 0.0025, 0.0093, 0.0260, 0.0564, 0.0967, 0.1330, 0.1477, 0.1330, 0.0967, 0.0564, 0.0260, 0.0093, 0.0025, 0.0005, 0.0001, 0.0000};
const double A2[] = {0.0001, -0.0014, 0.0096, -0.0423, 0.1340, -0.3250, 0.6243, -0.9708, 1.2386, -1.3057, 1.1399, -0.8221, 0.4862, -0.2326, 0.0881, -0.0255, 0.0053, -0.0007, 0.0000};
// Time delays for both filters
static double Z1[8];
static double Z2[18];

int main(void){
    /* Halting the Watchdog */
    MAP_WDT_A_holdTimer();
    
    //![Simple CS Config]
    /* Configuring pins for peripheral/crystal usage */
    MAP_GPIO_setAsPeripheralModuleFunctionOutputPin(GPIO_PORT_PJ,
            GPIO_PIN3 | GPIO_PIN2, GPIO_PRIMARY_MODULE_FUNCTION);

    /* Configure P5.6 and P5.7 to their analog functions to output VREF */
    P5SEL0 |= BIT6 | BIT7;
    P5SEL1 |= BIT6 | BIT7;

    REFCTL0 |= REFON;                     // Turn on reference module
    REFCTL0 |= REFOUT;                    // Output reference voltage to a pin

     /* Output VREF = 1.2V */
    REFCTL0 &= ~(REFVSEL_3);              // Clear existing VREF voltage level setting
    REFCTL0 |= REFVSEL_0;                 // Set VREF = 1.2V
    while (REFCTL0 & REFGENBUSY);       // Wait until the reference generation is settled


    /* Configuring pins for HFXT crystal */
    MAP_GPIO_setAsPeripheralModuleFunctionInputPin(GPIO_PORT_PJ,
            GPIO_PIN2 | GPIO_PIN3, GPIO_PRIMARY_MODULE_FUNCTION);

    /* Set P6.0 as output */
    MAP_GPIO_setAsOutputPin(GPIO_PORT_P1, GPIO_PIN0);

    /* Set all 8 pins of P2 as output */
    MAP_GPIO_setAsOutputPin(GPIO_PORT_P2, GPIO_PIN0 | GPIO_PIN1 | GPIO_PIN2 | GPIO_PIN3 | GPIO_PIN4 | GPIO_PIN5 | GPIO_PIN6 | GPIO_PIN7);

    /* Configuring GPIOs (4.3 MCLK) */
    MAP_GPIO_setAsPeripheralModuleFunctionOutputPin(GPIO_PORT_P4, GPIO_PIN3,
    GPIO_PRIMARY_MODULE_FUNCTION);

    /* Setting the external clock frequency. This API is optional, but will
     * come in handy if the user ever wants to use the getMCLK/getACLK/etc
     * functions
     */
    CS_setExternalClockSourceFrequency(32000,48000000);

    /* Starting HFXT in non-bypass mode without a timeout. Before we start
     * we have to change VCORE to 1 to support the 48MHz frequency */
    MAP_PCM_setCoreVoltageLevel(PCM_VCORE1);
    MAP_FlashCtl_setWaitState(FLASH_BANK0, 2);
    MAP_FlashCtl_setWaitState(FLASH_BANK1, 2);
    CS_startHFXT(false);

    /* Initialising MCLK to HFXT (effectively 48MHz) */
    MAP_CS_initClockSignal(CS_MCLK, CS_HFXTCLK_SELECT, CS_CLOCK_DIVIDER_1);

    /* Set SysTick to 48MHz/1000=48kHz*/
    MAP_SysTick_enableModule();
    MAP_SysTick_setPeriod(1000);
    MAP_Interrupt_enableSleepOnIsrExit();
    MAP_SysTick_enableInterrupt();

    /* Initialising ADC (MCLK/1//1) */
    MAP_ADC14_enableModule();
    MAP_ADC14_initModule(ADC_CLOCKSOURCE_MCLK, ADC_PREDIVIDER_1, ADC_DIVIDER_1, 0);

    /* Configuring GPIOs (P5.0 (A5) as the ADC input pin) */
    MAP_GPIO_setAsPeripheralModuleFunctionInputPin(GPIO_PORT_P5, GPIO_PIN0, GPIO_TERTIARY_MODULE_FUNCTION);

    /* Configure ADC Resolution */
    ADC14_setResolution(ADC_10BIT);

    /* Configuring ADC Memory */
    MAP_ADC14_configureSingleSampleMode(ADC_MEM0, true);
    MAP_ADC14_configureConversionMemory(ADC_MEM0, ADC_VREFPOS_INTBUF_VREFNEG_VSS, ADC_INPUT_A5, false);

    /* Configuring Sample Timer */
    MAP_ADC14_enableSampleTimer(ADC_MANUAL_ITERATION);

     /* Enabling MASTER interrupts */
    MAP_Interrupt_enableMaster();

    while (1){
        //MAP_PCM_gotoLPM0();
    }
}

void SysTick_Handler(void)
{
    double buffer = ADC14_getResult(ADC_MEM0);  //Get the conversion result.

    descramble(&buffer, Timer, B1, A1, B2, A2, Z1, Z2);

    Timer += 1/fs;
    P2OUT = buffer / 4;  //We do this because the ADC is set to use 10 bits but P2OUT is only 8 bits.

    /* Enabling/Toggling Conversion */
    MAP_ADC14_enableConversion();
    MAP_ADC14_toggleConversionTrigger();
    MAP_ADC14_toggleConversionTrigger();
}

void ADC14_IRQHandler(void)
{
    uint64_t status = MAP_ADC14_getEnabledInterruptStatus();
    MAP_ADC14_clearInterruptFlag(status);
}