BME680 XLSB

[JamesMeech]

Is there any way to get values to appear in the BME680 temperature XLSB with no or minimal oversampling? 

[BSTRobin]

Hello JamesMeech,

Could we know why you need to do this?

[JamesMeech]

I want to have the maximum resolution without averaging so I can try out some noise reduction algorithms on the sensor data

[JamesMeech]

I'll assume that this is not possible based on the fact that the question remains unanswered. 

[BSTRobin]

Hello JamesMeech,

BME680 supported over sampling. Please refer the following materials from data sheet.

/*!
* @brief This internal API is used to calculate the field data of sensor.
*/
static int8_t read_field_data(struct bme680_field_data *data, struct bme680_dev *dev)
{
int8_t rslt;
uint8_t buff[BME680_FIELD_LENGTH] = { 0 };
uint8_t gas_range;
uint32_t adc_temp;
uint32_t adc_pres;
uint16_t adc_hum;
uint16_t adc_gas_res;
uint8_t tries = 10;

/* Check for null pointer in the device structure*/
rslt = null_ptr_check(dev);
do {
if (rslt == BME680_OK) {
rslt = bme680_get_regs(((uint8_t) (BME680_FIELD0_ADDR)), buff, (uint16_t) BME680_FIELD_LENGTH,
dev);

data->status = buff[0] & BME680_NEW_DATA_MSK;
data->gas_index = buff[0] & BME680_GAS_INDEX_MSK;
data->meas_index = buff[1];

/* read the raw data from the sensor */
adc_pres = (uint32_t) (((uint32_t) buff[2] * 4096) | ((uint32_t) buff[3] * 16)
| ((uint32_t) buff[4] / 16));
adc_temp = (uint32_t) (((uint32_t) buff[5] * 4096) | ((uint32_t) buff[6] * 16)
| ((uint32_t) buff[7] / 16));
adc_hum = (uint16_t) (((uint32_t) buff[8] * 256) | (uint32_t) buff[9]);
adc_gas_res = (uint16_t) ((uint32_t) buff[13] * 4 | (((uint32_t) buff[14]) / 64));
gas_range = buff[14] & BME680_GAS_RANGE_MSK;

data->status |= buff[14] & BME680_GASM_VALID_MSK;
data->status |= buff[14] & BME680_HEAT_STAB_MSK;

if (data->status & BME680_NEW_DATA_MSK) {
data->temperature = calc_temperature(adc_temp, dev);
data->pressure = calc_pressure(adc_pres, dev);
data->humidity = calc_humidity(adc_hum, dev);
data->gas_resistance = calc_gas_resistance(adc_gas_res, gas_range, dev);
break;
}
/* Delay to poll the data */
dev->delay_ms(BME680_POLL_PERIOD_MS);
}
tries--;
} while (tries);

if (!tries)
rslt = BME680_W_NO_NEW_DATA;

return rslt;
}