平均值求sensor的ADC值算法

#define ADC_BUFFER_NUM 6

 int adc_value_buf[ADC_BUFFER_NUM];
 int adc_index_count; 

bool adc_buf_initialized;

 

static int get_adcvalue(struct ics_proximity_data *ics)
{
 int i = 0;
 int j = 0;
 unsigned int adc_total = 0;
 int adc_avr_value =0;
 unsigned int adc_index = 0;
 unsigned int adc_max = 0;
 unsigned int adc_min = 0;
 int value = 0;

 value = get_adc_value();

 adc_index = (adc_index_count++) % ADC_BUFFER_NUM;

 if (!ics->adc_buf_initialized) {
  ics->adc_buf_initialized = true;
  for (j = 0; j < ADC_BUFFER_NUM; j++)
    adc_value_buf[j] = value;
 } else
  ics->adc_value_buf[adc_index] = value;

 adc_max = adc_value_buf[0];
 adc_min = adc_value_buf[0];

 for (i = 0; i < ADC_BUFFER_NUM; i++) {
  adc_total += adc_value_buf[i];

  if (adc_max < adc_value_buf[i])
   adc_max = adc_value_buf[i];

  if (adc_min > adc_value_buf[i])
   adc_min = adc_value_buf[i];
 }
 adc_avr_value = (adc_total-(adc_max+adc_min))/(ADC_BUFFER_NUM-2);

 if (adc_index_count == ADC_BUFFER_NUM-1)
  adc_index_count = 0;

 printk(KERN_INFO "proximity adc=%d",adc_avr_value);

 return adc_avr_value;
}

 

主要算法:

1.用第一次的ADC值来填充所有的buf

2.取得最大和最小值

3.舍去最大值和最小值,并求平均值

4.buf下标用求余来填充相应的下标值