adc.c

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#include <adc.h>

int adc_read(unsigned int ch){  
    
    volatile int delay;
    
    #ifdef __MSP430F2274__
        switch(ch){
            case 0:
                ADC10CTL1 = INCH_0;
                break;
            case 1: 
                ADC10CTL1 = INCH_1;
                break;
            case 2:
                ADC10CTL1 = INCH_2;
                break;
            case 3:
                if((ADC10CTL0 & SREF_6))
                    return -EPERM;  /* Operation not permitted */      
                ADC10CTL1 = INCH_3;
                break;
            case 4:
                if((ADC10CTL0 & SREF_6))
                    return -EPERM; /* Operation not permitted */         
                ADC10CTL1 = INCH_4;
                break;
            case 12:
                ADC10CTL1 = INCH_12;
                break;
            case 13:
                ADC10CTL1 = INCH_13;
                break;
            case 14:
                ADC10CTL1 = INCH_14;
                break;
            case 15:
                ADC10CTL1 = INCH_15;
                break;
            default:
                return -EPERM; //Operation not permitted 
        }
    
    #elif defined(__MSP430G2553__)
        switch(ch){
            case 0:
                ADC10CTL1 = INCH_0;
                break;
            case 1: 
                ADC10CTL1 = INCH_1;
                break;
            case 2:
                ADC10CTL1 = INCH_2;
                break;
            case 3:
                if((ADC10CTL0 & SREF_6))
                    return -EPERM;  /* Operation not permitted */      
                ADC10CTL1 = INCH_3;
                break;
            case 4:
                if((ADC10CTL0 & SREF_6))
                    return -EPERM; /* Operation not permitted */         
                ADC10CTL1 = INCH_4;
                break;
            case 5:
                ADC10CTL1 = INCH_5;
                break;
            case 6:
                ADC10CTL1 = INCH_6;
                break;
            case 7:  
                ADC10CTL1 = INCH_7;
                break;
            default:
                return -EPERM; /* Operation not permitted */
        }
    #else
        #error "No such device!"
        return -ENXIO;
    #endif
    
    if(!( ADC10CTL0 && ADC10ON))
        adc_eref_off() ;                

    for(delay=35;delay==0;delay--);

    ADC10CTL0 |= ENC + ADC10SC;             // Sampling and conversion start
    __bis_SR_register(CPUOFF + GIE);        // LPM0, ADC10_ISR will force exit
    ADC10CTL0 |= ~ENC;

    return ADC10MEM;
}

int adc_eref_off() 
{
    #if defined(__MSP430G2553__) || defined(__MSP430F2274__)
    
        ADC10AE0 = 0xff;                    /* Seleção das portas como OUTPUT  */
    
        ADC10CTL0 |= ~ENC;
    
        ADC10CTL0 = 
        ADC10ON + 
        SREF_0+             /* Referencia VCC */
        ADC10SHT_3 + 
        ADC10IE; 
        return (ADC10CTL0 - (ADC10ON + SREF_0 + ADC10SHT_3 + ADC10IE));
    #else
        #error "No such device!"
        return -ENXIO; /* No such device */
    #endif
    
    
    return -ENXIO; /* No such device */
    }


int adc_eref_on() 
{
    #if defined(__MSP430F2274__) || defined(__MSP430G2553__)
        
/*      if( ADC10CTL0 && ADC10ON)
            return -EPERM; /* Operation not permitted */
            
        // Modo com referencia externa nos pinos 6 (-) e 7 (+)
            
        volatile int delay;
        ADC10AE0 |= 0x3ff;      /* seleção de todas as portas exceto as que correspondem a eref+/-  */
        
        ADC10CTL0 |= ~ENC;
        ADC10CTL0 |= 
        ADC10ON + 
        SREF_6+             /* Referencia VCC */
        ADC10SHT_3 + 
        ADC10IE; 
        
        for(delay=35;delay==0;delay--);
        return SUCCESS;
        
    
    #else
        #error "No such device!"
    #endif
    return -ENXIO;
}

void adc_close()
{
    #if defined(__MSP430G2553__) || defined(__MSP430F2274__)
        
    ADC10CTL1 |= ~ADC10ON;
        
    #endif
    
} 

// *************************************************************************************************
// @fn          ADC12ISR
// @brief       Store ADC12 conversion result. Set flag to indicate data ready.
// @param       none
// @return      none
// *************************************************************************************************
//Rotina de interrupção
#if defined(__MSP430G2553__) || defined(__MSP430F2274__)

    /* pfs wrapped the following to accommodate mspgcc compiler */
    #ifdef __GNUC__
    #include <legacymsp430.h>
    interrupt (ADC10_VECTOR) ADC10ISR (void)
    #else
    #pragma vector=ADC10_VECTOR
    __interrupt void ADC10ISR (void)
    #endif
{
    __bic_SR_register_on_exit(LPM0_bits + GIE);
}
#else
    #error "No such device!"
        
#endif