ecomp_ex1_outputToggleVcompVsVref1.5V.c

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//******************************************************************************
// MSP430FR2311 Demo - EComp Toggle from LPM4; input channel C0;
//      Vcompare is compared against the internal reference 1.5V
//
// Description: Use CompE (input channel C0) and internal reference to
//    determine if input'Vcompare'is high or low.  When Vcompare exceeds 1.5V
//    COUT goes high and when Vcompare is less than 1.5V then COUT goes low.
//
//
//                 MSP430FR2311
//             ------------------
//         /|\|                  |
//          | |                  |
//          --|RST        P1.0/C0|<--Vcompare
//            |                  |
//            |         P2.0/COUT|----> 'high'(Vcompare>1.5V); 'low'(Vcompare<1.5V)
//            |                  | 
//            |                  | 
//            |                  |
//
 
//******************************************************************************
 
#include "driverlib.h"
 
void main(void)
{
    //Stop WDT
    WDT_A_hold(WDT_A_BASE);
 
    //Set P2.0 as Secondary Module Function Output.(COUT)
    GPIO_setAsPeripheralModuleFunctionOutputPin(
        GPIO_PORT_P2,
        GPIO_PIN0,
        GPIO_SECONDARY_MODULE_FUNCTION
    );
 
    /*
     * Disable the GPIO power-on default high-impedance mode to activate
     * previously configured port settings
     */
    PMM_unlockLPM5();
 
    //Initialize the EComp module
    /* Base Address of EComp,
    * Pin C0 to Positive(+) Terminal,
    * Reference Voltage (from DAC) to Negative(-) Terminal,
    * Output Filter delay off,
    * Non-Inverted Output Polarity
    */
    EComp_initParam param = {0};
    param.positiveTerminalInput = ECOMP_INPUT_0;
    param.negativeTerminalInput = ECOMP_INPUT_DAC;
    param.outputFilterEnableAndDelayLevel = ECOMP_FILTER_DELAY_OFF;
    param.invertedOutputPolarity = ECOMP_NORMAL_OUTPUT_POLARITY;
    EComp_init(ECOMP0_BASE, &param);
 
    //Set the reference voltage that is outputed by built-in DAC
    EComp_configureDACParam dacParam = {0};
    dacParam.referenceVoltage = ECOMP_DAC_REFERENCE_VOLTAGE_VREF;
    dacParam.bufferSource = ECOMP_DAC_BUFFER_SOURCE_DUAL_BUFFER_1;
    dacParam.firstBufferData = 63;
    EComp_configureDAC(ECOMP0_BASE, &dacParam);
    EComp_enableDAC(ECOMP0_BASE);
 
    //Select low power low speed mode
    EComp_selectPowerMode(ECOMP0_BASE, ECOMP_POWER_MODE_LOW_POWER_LOW_SPEED);
 
    //Allow power to Comparator module
    EComp_enable(ECOMP0_BASE);
 
    __bis_SR_register(LPM4_bits);          // Enter LPM4
    __no_operation();                      // For debug
}