adc_driver.c

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/* This file has been prepared for Doxygen automatic documentation generation.*/
#include "adc_driver.h"


void ADC_CalibrationValues_Set(ADC_t * adc)
{
    if(&ADCA == adc){
         /* Get ADCCAL0 from byte address 0x20 (Word address 0x10. */
        adc->CAL = SP_ReadCalibrationByte(0x20);
    }else {
        /* Get ADCCAL0 from byte address 0x24 (Word address 0x12. */
        adc->CAL = SP_ReadCalibrationByte(0x24);
    }
}


uint16_t ADC_ResultCh_GetWord(ADC_CH_t * adc_ch, uint8_t offset)
{
    uint16_t answer;
    uint16_t signedOffset = (uint16_t) offset;

    /* Append 16-bit signed value if offset (signed) is negative. */
    if (offset >= 128){
        signedOffset |= 0xFF00;
    }

    /* Clear interrupt flag.*/
    adc_ch->INTFLAGS = ADC_CH_CHIF_bm;

    /* Return result register contents*/
    answer = adc_ch->RES - signedOffset;

    return answer;
}


uint8_t ADC_ResultCh_GetLowByte(ADC_CH_t * adc_ch, uint8_t offset)
{
    uint8_t answer;

    /* Clear interrupt flag.*/
    adc_ch->INTFLAGS = ADC_CH_CHIF_bm;
    /* Return result register contents*/
    answer = adc_ch->RESL - offset;

    return answer;
}

uint8_t ADC_ResultCh_GetHighByte(ADC_CH_t * adc_ch)
{
    /* Clear interrupt flag.*/
    adc_ch->INTFLAGS = ADC_CH_CHIF_bm;

    /* Return low byte result register contents.*/
    return adc_ch->RESH;
}

void ADC_Wait_8MHz(ADC_t * adc)
{
    /* Store old prescaler value. */
    uint8_t prescaler_val = adc->PRESCALER;

    /* Set prescaler value to minimum value. */
    adc->PRESCALER = ADC_PRESCALER_DIV4_gc;

    /* Wait 4*COMMEN_MODE_CYCLES for common mode to settle. */
    delay_us(4*COMMEN_MODE_CYCLES);

    /* Set prescaler to old value*/
    adc->PRESCALER = prescaler_val;
}


void ADC_Wait_32MHz(ADC_t * adc)
{
    /* Store old prescaler value. */
    uint8_t prescaler_val = adc->PRESCALER;

    /* Set prescaler value to minimum value. */
    adc->PRESCALER = ADC_PRESCALER_DIV8_gc;

    /* wait 8*COMMEN_MODE_CYCLES for common mode to settle*/
    delay_us(8*COMMEN_MODE_CYCLES);

    /* Set prescaler to old value*/
    adc->PRESCALER = prescaler_val;
}

uint8_t ADC_Offset_Get(ADC_t * adc)
{
    uint8_t offset;

    /* Set up ADC to get offset. */
    ADC_ConvMode_and_Resolution_Config(adc, true, ADC_RESOLUTION_12BIT_gc);

    ADC_Prescaler_Config(adc , ADC_PRESCALER_DIV8_gc);

    ADC_Referance_Config(adc , ADC_REFSEL_INTVCC_gc);

    ADC_Ch_InputMode_and_Gain_Config(&(adc->CH0),
                                     ADC_CH_INPUTMODE_DIFF_gc,
                                     ADC_CH_GAIN_1X_gc);

    ADC_Ch_InputMux_Config(&(adc->CH0), ADC_CH_MUXPOS_PIN0_gc, ADC_CH_MUXNEG_PIN0_gc);

    /* Enable ADC. */
    ADC_Enable(adc);

    /* Wait until ADC is ready. */
    ADC_Wait_32MHz(adc);

    /* Do one conversion to find offset. */
    ADC_Ch_Conversion_Start(&(adc->CH0));

    do{
    }while(!ADC_Ch_Conversion_Complete(&(adc->CH0)));
    offset = ADC_ResultCh_GetLowByte(&(adc->CH0), 0x00);

    /* Disable ADC. */
    ADC_Disable(adc);

    return offset;
}

#ifdef __GNUC__

uint8_t SP_ReadCalibrationByte( uint8_t index )
{
    uint8_t result;

    /* Load the NVM Command register to read the calibration row. */
    NVM_CMD = NVM_CMD_READ_CALIB_ROW_gc;
    result = pgm_read_byte(index);

    /* Clean up NVM Command register. */
    NVM_CMD = NVM_CMD_NO_OPERATION_gc;

    return result;
}

#endif