sd24_ex3_continuousConversionSingleChannel.c

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//******************************************************************************
//  MSP430i20xx SD24 Example 03 - SD24, Continuous Conversion on a Single Channel
//
//  Description: This program uses the SD24 module to perform continuous
//  conversions on a single channel. A SD24 interrupt occurs when a conversion
//  has completed.
//
//  Test by applying voltages to the input channel and setting a breakpoint
//  at the indicated line. Run program until it reaches the breakpoint, then use
//  the debugger's watch window to view the conversion results.
//
//  Results (upper 16 bits only) are stored in the array "results"
//
//  ACLK = 32kHz, MCLK = SMCLK = Calibrated DCO = 16.384MHz, SD_CLK = 1.024MHz
//  * Ensure low_level_init.c is included when building/running this example *
//
//  Notes: For minimum Vcc required for SD24 module - see datasheet
//         100nF cap btw Vref and AVss is recommended when using 1.2V ref
//
//               MSP430i20xx
//             -----------------
//         /|\|                |
//          | |                |
//          --|RST             |
//            |                |
//   Vin1+ -->|A0.0+      VREF |---+
//   Vin1- -->|A0.0-           |   |
//            |                |  -+- 100nF
//            |                |  -+-
//            |                |   |
//            |           AVss |---+
//
//  T. Witt
//  Yang Lu
//  Texas Instruments, Inc
//  June 2014
//  Built with Code Composer Studio v5.5
//******************************************************************************
#include "driverlib.h"
 
/* Array to store SD24 conversion results */
uint16_t results[8];
 
void main(void) {
    // Stop WDT
    WDT_hold(WDT_BASE);  
 
    // Internal ref
    SD24_init(SD24_BASE, SD24_REF_INTERNAL);
    //Group with Channel 0
    SD24_initConverterAdvancedParam param = {0};
    param.converter = SD24_CONVERTER_0;
    param.conversionMode = SD24_CONTINUOUS_MODE;
    param.groupEnable = SD24_NOT_GROUPED;
    param.inputChannel = SD24_INPUT_CH_ANALOG;
    param.dataFormat = SD24_DATA_FORMAT_2COMPLEMENT;
    param.interruptDelay = SD24_FOURTH_SAMPLE_INTERRUPT;
    param.oversampleRatio = SD24_OVERSAMPLE_256;
    param.gain = SD24_GAIN_1;
    SD24_initConverterAdvanced(SD24_BASE, &param);
    SD24_enableInterrupt(SD24_BASE, SD24_CONVERTER_0, SD24_CONVERTER_INTERRUPT);
 
    // Delay ~200us for 1.2V ref to settle
    __delay_cycles(3200);
 
    // Start conversion
    SD24_startConverterConversion(SD24_BASE, SD24_CONVERTER_0);
    // Enter LPM0 w/ interrupts
    __bis_SR_register(LPM0_bits | GIE);
}
 
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector=SD24_VECTOR
__interrupt void SD24_ISR(void) {
#elif defined(__GNUC__)
void __attribute__ ((interrupt(SD24_VECTOR))) SD24_ISR (void) {
#else
#error Compiler not supported!
#endif
    static unsigned char index = 0;
    switch (__even_in_range(SD24IV,SD24IV_SD24MEM3)) {
        case SD24IV_NONE: break;
        case SD24IV_SD24OVIFG: break;
        case SD24IV_SD24MEM0:
                   // Save CH0 results (clears IFG)
                   results[index++] = SD24_getHighWordResults(SD24_BASE, SD24_CONVERTER_0);
                   if(index >= 8) {
                       index = 0;               // SET BREAKPOINT HERE
                   }
                   break;
        case SD24IV_SD24MEM1: break;
        case SD24IV_SD24MEM2: break;
        case SD24IV_SD24MEM3: break;
        default: break;
    }
}