si114x_uv_index.c

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/**************************************************************************/
#include "si114x_functions.h"

#define UV_TASKLIST           0x80              
#define UV_IRQ_EN             IE_ALS_EVRYSAMPLE 
#define SI1146_DEVICE_ID      0x46              
/**************************************************************************/
static void * si114x_handle;

/**************************************************************************/
int Si114x_MeasureUVIndex(u16 *uvIndex)
{
  u16 data;
  volatile u8 regval;
  int      retval = 0;
  Si114xPsAlsForce(si114x_handle);


  regval = Si114xReadFromRegister(si114x_handle, REG_AUX_DATA0); /*read sample data from si114x */
  data = regval;
  regval = Si114xReadFromRegister(si114x_handle, REG_AUX_DATA1);
  data |= regval << 8;

  //check for saturation after the forced measurement and clear it if found
  //otherwise the next si114x cmd will not be performed.  Also this must be
  //done after reading the AUX_DATA register
  regval = Si114xReadFromRegister(si114x_handle, REG_RESPONSE);
  while((regval & 0x80) != 0)      //response == 0x8x means saturation occured
  {   // Send the NOP Command to clear the error...we cannot use Si114xNop()
      // because it first checks if REG_RESPONSE < 0 and if so it does not
      // perform the cmd. Since we have a saturation REG_RESPONSE will be <0
      Si114xWriteToRegister(si114x_handle, REG_COMMAND, 0x00);
      regval = Si114xReadFromRegister(si114x_handle, REG_RESPONSE);

  }


  /*round to nearest*/
  *uvIndex  = data + 50;
  *uvIndex /= 100;
  /*clear irq*/

  if(*uvIndex > 10)
      *uvIndex  = data + 50;
  Si114xWriteToRegister(si114x_handle, REG_IRQ_STATUS, 0xff);
  return retval;
}


/**************************************************************************/
int Si114x_EnableVisRange(int vis_range_bit)
{   s16         retval = 0;
    if( vis_range_bit == 1 )
        retval += Si114xParamSet(si114x_handle, PARAM_ALSVIS_ADC_MISC, RANGE_EN);
    else
        retval += Si114xParamSet(si114x_handle, PARAM_ALSVIS_ADC_MISC, 0);

    return retval;
}



/**************************************************************************/
int Si114x_ConfigureUV(int fullInit, HANDLE *handle)
{
  s16          retval = 0;
  SI114X_CAL_S si114x_cal;

  /* Set handle */
  si114x_handle = *handle;

  /* Note that the Si114xReset() actually performs the following functions: */
  /*     1. Pauses all prior measurements */
  /*     2. Clear  i2c registers that need to be cleared */
  /*     3. Clears irq status to make sure INT* is negated */
  /*     4. Delays 10 ms */
  /*     5. Sends HW Key */
  if (fullInit)
     retval += Si114xReset(si114x_handle);

  /* UV Coefficients */
  si114x_get_calibration(si114x_handle, &si114x_cal, 0);
  si114x_set_ucoef(si114x_handle, 0, &si114x_cal);


  if (fullInit)
  {
     retval += Si114xParamSet(si114x_handle, PARAM_CH_LIST, UV_TASKLIST);
     retval += Si114xWriteToRegister(si114x_handle, REG_IRQ_ENABLE, IE_ALS_EVRYSAMPLE);

     retval += Si114xParamSet(si114x_handle, PARAM_PS_ADC_MISC, 0x24);  /* PS_ADC_MISC to high signal range */
     retval += Si114xParamSet(si114x_handle, PARAM_PS1_ADC_MUX, 0x00);  /* PS1_ADCMUX, PS2_ADCMUX, PS3_ADCMUX to small photodiode */
     retval += Si114xParamSet(si114x_handle, PARAM_PS2_ADC_MUX, 0x00);
     retval += Si114xParamSet(si114x_handle, PARAM_PS3_ADC_MUX, 0x00);
  }
  /* Configure the ALS IR channel for the same settings as PS */
  retval += Si114xParamSet(si114x_handle, PARAM_ALSIR_ADC_MISC, RANGE_EN);
  retval += Si114xParamSet(si114x_handle, PARAM_ALSVIS_ADC_MISC, RANGE_EN);
  /* If nothing went wrong after all of this time, the value */
  /* returned will be 0. Otherwise, it will be some negative */
  /* number */
  return retval;
}