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49 @brief Sensor driver for BME280 sensor */
52 /**\name Internal macros */
53 /* To identify osr settings selected by user */
54 #define OVERSAMPLING_SETTINGS UINT8_C(0x07)
55 /* To identify filter and standby settings selected by user */
56 #define FILTER_STANDBY_SETTINGS UINT8_C(0x18)
59 * @brief This internal API puts the device to sleep mode.
61 * @param[in] dev : Structure instance of bme280_dev.
63 * @return Result of API execution status.
64 * @retval zero -> Success / +ve value -> Warning / -ve value -> Error
66 static int8_t put_device_to_sleep(const struct bme280_dev *dev);
69 * @brief This internal API writes the power mode in the sensor.
71 * @param[in] dev : Structure instance of bme280_dev.
72 * @param[in] sensor_mode : Variable which contains the power mode to be set.
74 * @return Result of API execution status.
75 * @retval zero -> Success / +ve value -> Warning / -ve value -> Error
77 static int8_t write_power_mode(uint8_t sensor_mode, const struct bme280_dev *dev);
80 * @brief This internal API is used to validate the device pointer for
83 * @param[in] dev : Structure instance of bme280_dev.
85 * @return Result of API execution status
86 * @retval zero -> Success / +ve value -> Warning / -ve value -> Error
88 static int8_t null_ptr_check(const struct bme280_dev *dev);
91 * @brief This internal API interleaves the register address between the
92 * register data buffer for burst write operation.
94 * @param[in] reg_addr : Contains the register address array.
95 * @param[out] temp_buff : Contains the temporary buffer to store the
96 * register data and register address.
97 * @param[in] reg_data : Contains the register data to be written in the
99 * @param[in] len : No of bytes of data to be written for burst write.
101 static void interleave_reg_addr(const uint8_t *reg_addr, uint8_t *temp_buff, const uint8_t *reg_data, uint8_t len);
104 * @brief This internal API reads the calibration data from the sensor, parse
105 * it and store in the device structure.
107 * @param[in] dev : Structure instance of bme280_dev.
109 * @return Result of API execution status
110 * @retval zero -> Success / +ve value -> Warning / -ve value -> Error
112 static int8_t get_calib_data(struct bme280_dev *dev);
115 * @brief This internal API is used to parse the temperature and
116 * pressure calibration data and store it in the device structure.
118 * @param[out] dev : Structure instance of bme280_dev to store the calib data.
119 * @param[in] reg_data : Contains the calibration data to be parsed.
121 static void parse_temp_press_calib_data(const uint8_t *reg_data, struct bme280_dev *dev);
124 * @brief This internal API is used to parse the humidity calibration data
125 * and store it in device structure.
127 * @param[out] dev : Structure instance of bme280_dev to store the calib data.
128 * @param[in] reg_data : Contains calibration data to be parsed.
130 static void parse_humidity_calib_data(const uint8_t *reg_data, struct bme280_dev *dev);
133 * @brief This internal API is used to parse the pressure, temperature and
134 * humidity data and store it in the bme280_uncomp_data structure instance.
136 * @param[in] reg_data : Contains the register data which needs to be parsed.
137 * @param[out] uncomp_data : Contains the uncompensated pressure, temperature
140 static void parse_sensor_data(const uint8_t *reg_data, struct bme280_uncomp_data *uncomp_data);
143 * @brief This internal API is used to compensate the pressure and/or
144 * temperature and/or humidity data according to the component selected by the
147 * @param[in] sensor_comp : Used to select pressure and/or temperature and/or
149 * @param[in] uncomp_data : Contains the uncompensated pressure, temperature and
151 * @param[out] comp_data : Contains the compensated pressure and/or temperature
152 * and/or humidity data.
153 * @param[in] calib_data : Pointer to the calibration data structure.
155 * @return Result of API execution status.
156 * @retval zero -> Success / -ve value -> Error
158 static int8_t compensate_data(uint8_t sensor_comp, const struct bme280_uncomp_data *uncomp_data,
159 struct bme280_data *comp_data, struct bme280_calib_data *calib_data);
161 #ifdef FLOATING_POINT_REPRESENTATION
163 * @brief This internal API is used to compensate the raw pressure data and
164 * return the compensated pressure data in double data type.
166 * @param[in] uncomp_data : Contains the uncompensated pressure data.
167 * @param[in] calib_data : Pointer to the calibration data structure.
169 * @return Compensated pressure data.
170 * @retval Compensated pressure data in double.
172 static double compensate_pressure(const struct bme280_uncomp_data *uncomp_data,
173 const struct bme280_calib_data *calib_data);
176 * @brief This internal API is used to compensate the raw humidity data and
177 * return the compensated humidity data in double data type.
179 * @param[in] uncomp_data : Contains the uncompensated humidity data.
180 * @param[in] calib_data : Pointer to the calibration data structure.
182 * @return Compensated humidity data.
183 * @retval Compensated humidity data in double.
185 static double compensate_humidity(const struct bme280_uncomp_data *uncomp_data,
186 const struct bme280_calib_data *calib_data);
189 * @brief This internal API is used to compensate the raw temperature data and
190 * return the compensated temperature data in double data type.
192 * @param[in] uncomp_data : Contains the uncompensated temperature data.
193 * @param[in] calib_data : Pointer to calibration data structure.
195 * @return Compensated temperature data.
196 * @retval Compensated temperature data in double.
198 static double compensate_temperature(const struct bme280_uncomp_data *uncomp_data,
199 struct bme280_calib_data *calib_data);
204 * @brief This internal API is used to compensate the raw temperature data and
205 * return the compensated temperature data in integer data type.
207 * @param[in] uncomp_data : Contains the uncompensated temperature data.
208 * @param[in] calib_data : Pointer to calibration data structure.
210 * @return Compensated temperature data.
211 * @retval Compensated temperature data in integer.
213 static int32_t compensate_temperature(const struct bme280_uncomp_data *uncomp_data,
214 struct bme280_calib_data *calib_data);
217 * @brief This internal API is used to compensate the raw pressure data and
218 * return the compensated pressure data in integer data type.
220 * @param[in] uncomp_data : Contains the uncompensated pressure data.
221 * @param[in] calib_data : Pointer to the calibration data structure.
223 * @return Compensated pressure data.
224 * @retval Compensated pressure data in integer.
226 static uint32_t compensate_pressure(const struct bme280_uncomp_data *uncomp_data,
227 const struct bme280_calib_data *calib_data);
230 * @brief This internal API is used to compensate the raw humidity data and
231 * return the compensated humidity data in integer data type.
233 * @param[in] uncomp_data : Contains the uncompensated humidity data.
234 * @param[in] calib_data : Pointer to the calibration data structure.
236 * @return Compensated humidity data.
237 * @retval Compensated humidity data in integer.
239 static uint32_t compensate_humidity(const struct bme280_uncomp_data *uncomp_data,
240 const struct bme280_calib_data *calib_data);
245 * @brief This internal API is used to identify the settings which the user
246 * wants to modify in the sensor.
248 * @param[in] sub_settings : Contains the settings subset to identify particular
249 * group of settings which the user is interested to change.
250 * @param[in] desired_settings : Contains the user specified settings.
252 * @return Indicates whether user is interested to modify the settings which
253 * are related to sub_settings.
254 * @retval True -> User wants to modify this group of settings
255 * @retval False -> User does not want to modify this group of settings
257 static uint8_t are_settings_changed(uint8_t sub_settings, uint8_t desired_settings);
260 * @brief This API sets the humidity oversampling settings of the sensor.
262 * @param[in] dev : Structure instance of bme280_dev.
264 * @return Result of API execution status
265 * @retval zero -> Success / +ve value -> Warning / -ve value -> Error
267 static int8_t set_osr_humidity_settings(const struct bme280_settings *settings, const struct bme280_dev *dev);
270 * @brief This internal API sets the oversampling settings for pressure,
271 * temperature and humidity in the sensor.
273 * @param[in] desired_settings : Variable used to select the settings which
275 * @param[in] dev : Structure instance of bme280_dev.
277 * @return Result of API execution status
278 * @retval zero -> Success / +ve value -> Warning / -ve value -> Error
280 static int8_t set_osr_settings(uint8_t desired_settings, const struct bme280_settings *settings,
281 const struct bme280_dev *dev);
284 * @brief This API sets the pressure and/or temperature oversampling settings
285 * in the sensor according to the settings selected by the user.
287 * @param[in] dev : Structure instance of bme280_dev.
288 * @param[in] desired_settings: variable to select the pressure and/or
289 * temperature oversampling settings.
291 * @return Result of API execution status
292 * @retval zero -> Success / +ve value -> Warning / -ve value -> Error
294 static int8_t set_osr_press_temp_settings(uint8_t desired_settings, const struct bme280_settings *settings,
295 const struct bme280_dev *dev);
298 * @brief This internal API fills the pressure oversampling settings provided by
299 * the user in the data buffer so as to write in the sensor.
301 * @param[in] dev : Structure instance of bme280_dev.
302 * @param[out] reg_data : Variable which is filled according to the pressure
303 * oversampling data provided by the user.
305 static void fill_osr_press_settings(uint8_t *reg_data, const struct bme280_settings *settings);
308 * @brief This internal API fills the temperature oversampling settings provided
309 * by the user in the data buffer so as to write in the sensor.
311 * @param[in] dev : Structure instance of bme280_dev.
312 * @param[out] reg_data : Variable which is filled according to the temperature
313 * oversampling data provided by the user.
315 static void fill_osr_temp_settings(uint8_t *reg_data, const struct bme280_settings *settings);
318 * @brief This internal API sets the filter and/or standby duration settings
319 * in the sensor according to the settings selected by the user.
321 * @param[in] dev : Structure instance of bme280_dev.
322 * @param[in] desired_settings : variable to select the filter and/or
323 * standby duration settings.
325 * @return Result of API execution status
326 * @retval zero -> Success / +ve value -> Warning / -ve value -> Error
328 static int8_t set_filter_standby_settings(uint8_t desired_settings, const struct bme280_settings *settings,
329 const struct bme280_dev *dev);
332 * @brief This internal API fills the filter settings provided by the user
333 * in the data buffer so as to write in the sensor.
335 * @param[in] dev : Structure instance of bme280_dev.
336 * @param[out] reg_data : Variable which is filled according to the filter
337 * settings data provided by the user.
339 static void fill_filter_settings(uint8_t *reg_data, const struct bme280_settings *settings);
342 * @brief This internal API fills the standby duration settings provided by the
343 * user in the data buffer so as to write in the sensor.
345 * @param[in] dev : Structure instance of bme280_dev.
346 * @param[out] reg_data : Variable which is filled according to the standby
347 * settings data provided by the user.
349 static void fill_standby_settings(uint8_t *reg_data, const struct bme280_settings *settings);
352 * @brief This internal API parse the oversampling(pressure, temperature
353 * and humidity), filter and standby duration settings and store in the
356 * @param[out] dev : Structure instance of bme280_dev.
357 * @param[in] reg_data : Register data to be parsed.
359 static void parse_device_settings(const uint8_t *reg_data, struct bme280_settings *settings);
362 * @brief This internal API reloads the already existing device settings in the
363 * sensor after soft reset.
365 * @param[in] dev : Structure instance of bme280_dev.
366 * @param[in] settings : Pointer variable which contains the settings to
367 * be set in the sensor.
369 * @return Result of API execution status
370 * @retval zero -> Success / +ve value -> Warning / -ve value -> Error
372 static int8_t reload_device_settings(const struct bme280_settings *settings, const struct bme280_dev *dev);
374 /****************** Global Function Definitions *******************************/
377 * @brief This API is the entry point.
378 * It reads the chip-id and calibration data from the sensor.
380 int8_t bme280_init(struct bme280_dev *dev)
383 /* chip id read try count */
384 uint8_t try_count = 5;
387 /* Check for null pointer in the device structure*/
388 rslt = null_ptr_check(dev);
389 /* Proceed if null check is fine */
390 if (rslt == BME280_OK) {
392 /* Read the chip-id of bme280 sensor */
393 rslt = bme280_get_regs(BME280_CHIP_ID_ADDR, &chip_id, 1, dev);
394 /* Check for chip id validity */
395 if ((rslt == BME280_OK) && (chip_id == BME280_CHIP_ID)) {
396 dev->chip_id = chip_id;
397 /* Reset the sensor */
398 rslt = bme280_soft_reset(dev);
399 if (rslt == BME280_OK) {
400 /* Read the calibration data */
401 rslt = get_calib_data(dev);
409 /* Chip id check failed */
411 rslt = BME280_E_DEV_NOT_FOUND;
418 * @brief This API reads the data from the given register address of the sensor.
420 int8_t bme280_get_regs(uint8_t reg_addr, uint8_t *reg_data, uint16_t len, const struct bme280_dev *dev)
424 /* Check for null pointer in the device structure*/
425 rslt = null_ptr_check(dev);
426 /* Proceed if null check is fine */
427 if (rslt == BME280_OK) {
428 /* If interface selected is SPI */
429 if (dev->interface != BME280_I2C_INTF)
430 reg_addr = reg_addr | 0x80;
432 rslt = dev->read(dev->id, reg_addr, reg_data, len);
433 /* Check for communication error */
434 if (rslt != BME280_OK)
435 rslt = BME280_E_COMM_FAIL;
442 * @brief This API writes the given data to the register address
445 int8_t bme280_set_regs(uint8_t *reg_addr, const uint8_t *reg_data, uint8_t len, const struct bme280_dev *dev)
448 uint8_t temp_buff[len * 2];
450 uint8_t reg_addr_cnt;
452 /* Check for null pointer in the device structure*/
453 rslt = null_ptr_check(dev);
454 /* Check for arguments validity */
455 if ((rslt == BME280_OK) && (reg_addr != NULL) && (reg_data != NULL)) {
457 temp_buff[0] = reg_data[0];
458 /* If interface selected is SPI */
459 if (dev->interface != BME280_I2C_INTF) {
460 for (reg_addr_cnt = 0; reg_addr_cnt < len; reg_addr_cnt++)
461 reg_addr[reg_addr_cnt] = reg_addr[reg_addr_cnt] & 0x7F;
463 /* Burst write mode */
465 /* Interleave register address w.r.t data for
467 interleave_reg_addr(reg_addr, temp_buff, reg_data, len);
472 rslt = dev->write(dev->id, reg_addr[0], temp_buff, temp_len);
473 /* Check for communication error */
474 if (rslt != BME280_OK)
475 rslt = BME280_E_COMM_FAIL;
477 rslt = BME280_E_INVALID_LEN;
480 rslt = BME280_E_NULL_PTR;
488 * @brief This API sets the oversampling, filter and standby duration
489 * (normal mode) settings in the sensor.
491 int8_t bme280_set_sensor_settings(uint8_t desired_settings, const struct bme280_dev *dev)
496 /* Check for null pointer in the device structure*/
497 rslt = null_ptr_check(dev);
498 /* Proceed if null check is fine */
499 if (rslt == BME280_OK) {
500 rslt = bme280_get_sensor_mode(&sensor_mode, dev);
501 if ((rslt == BME280_OK) && (sensor_mode != BME280_SLEEP_MODE))
502 rslt = put_device_to_sleep(dev);
503 if (rslt == BME280_OK) {
504 /* Check if user wants to change oversampling
506 if (are_settings_changed(OVERSAMPLING_SETTINGS, desired_settings))
507 rslt = set_osr_settings(desired_settings, &dev->settings, dev);
508 /* Check if user wants to change filter and/or
510 if ((rslt == BME280_OK) && are_settings_changed(FILTER_STANDBY_SETTINGS, desired_settings))
511 rslt = set_filter_standby_settings(desired_settings, &dev->settings, dev);
519 * @brief This API gets the oversampling, filter and standby duration
520 * (normal mode) settings from the sensor.
522 int8_t bme280_get_sensor_settings(struct bme280_dev *dev)
527 /* Check for null pointer in the device structure*/
528 rslt = null_ptr_check(dev);
529 /* Proceed if null check is fine */
530 if (rslt == BME280_OK) {
531 rslt = bme280_get_regs(BME280_CTRL_HUM_ADDR, reg_data, 4, dev);
532 if (rslt == BME280_OK)
533 parse_device_settings(reg_data, &dev->settings);
540 * @brief This API sets the power mode of the sensor.
542 int8_t bme280_set_sensor_mode(uint8_t sensor_mode, const struct bme280_dev *dev)
545 uint8_t last_set_mode;
547 /* Check for null pointer in the device structure*/
548 rslt = null_ptr_check(dev);
550 if (rslt == BME280_OK) {
551 rslt = bme280_get_sensor_mode(&last_set_mode, dev);
552 /* If the sensor is not in sleep mode put the device to sleep
554 if ((rslt == BME280_OK) && (last_set_mode != BME280_SLEEP_MODE))
555 rslt = put_device_to_sleep(dev);
556 /* Set the power mode */
557 if (rslt == BME280_OK)
558 rslt = write_power_mode(sensor_mode, dev);
565 * @brief This API gets the power mode of the sensor.
567 int8_t bme280_get_sensor_mode(uint8_t *sensor_mode, const struct bme280_dev *dev)
571 /* Check for null pointer in the device structure*/
572 rslt = null_ptr_check(dev);
574 if (rslt == BME280_OK) {
575 /* Read the power mode register */
576 rslt = bme280_get_regs(BME280_PWR_CTRL_ADDR, sensor_mode, 1, dev);
577 /* Assign the power mode in the device structure */
578 *sensor_mode = BME280_GET_BITS_POS_0(*sensor_mode, BME280_SENSOR_MODE);
585 * @brief This API performs the soft reset of the sensor.
587 int8_t bme280_soft_reset(const struct bme280_dev *dev)
590 uint8_t reg_addr = BME280_RESET_ADDR;
591 /* 0xB6 is the soft reset command */
592 uint8_t soft_rst_cmd = 0xB6;
594 /* Check for null pointer in the device structure*/
595 rslt = null_ptr_check(dev);
596 /* Proceed if null check is fine */
597 if (rslt == BME280_OK) {
598 /* Write the soft reset command in the sensor */
599 rslt = bme280_set_regs(®_addr, &soft_rst_cmd, 1, dev);
600 /* As per data sheet, startup time is 2 ms. */
608 * @brief This API reads the pressure, temperature and humidity data from the
609 * sensor, compensates the data and store it in the bme280_data structure
610 * instance passed by the user.
612 int8_t bme280_get_sensor_data(uint8_t sensor_comp, struct bme280_data *comp_data, struct bme280_dev *dev)
615 /* Array to store the pressure, temperature and humidity data read from
617 uint8_t reg_data[BME280_P_T_H_DATA_LEN] = {0};
618 struct bme280_uncomp_data uncomp_data = {0};
620 /* Check for null pointer in the device structure*/
621 rslt = null_ptr_check(dev);
623 if ((rslt == BME280_OK) && (comp_data != NULL)) {
624 /* Read the pressure and temperature data from the sensor */
625 rslt = bme280_get_regs(BME280_DATA_ADDR, reg_data, BME280_P_T_H_DATA_LEN, dev);
627 if (rslt == BME280_OK) {
628 /* Parse the read data from the sensor */
629 parse_sensor_data(reg_data, &uncomp_data);
630 /* Compensate the pressure and/or temperature and/or
631 humidity data from the sensor */
632 rslt = compensate_data(sensor_comp, &uncomp_data, comp_data, &dev->calib_data);
635 rslt = BME280_E_NULL_PTR;
642 * @brief This internal API sets the oversampling settings for pressure,
643 * temperature and humidity in the sensor.
645 static int8_t set_osr_settings(uint8_t desired_settings, const struct bme280_settings *settings,
646 const struct bme280_dev *dev)
648 int8_t rslt = BME280_W_INVALID_OSR_MACRO;
650 if (desired_settings & BME280_OSR_HUM_SEL)
651 rslt = set_osr_humidity_settings(settings, dev);
652 if (desired_settings & (BME280_OSR_PRESS_SEL | BME280_OSR_TEMP_SEL))
653 rslt = set_osr_press_temp_settings(desired_settings, settings, dev);
659 * @brief This API sets the humidity oversampling settings of the sensor.
661 static int8_t set_osr_humidity_settings(const struct bme280_settings *settings, const struct bme280_dev *dev)
666 uint8_t reg_addr = BME280_CTRL_HUM_ADDR;
668 ctrl_hum = settings->osr_h & BME280_CTRL_HUM_MSK;
669 /* Write the humidity control value in the register */
670 rslt = bme280_set_regs(®_addr, &ctrl_hum, 1, dev);
671 /* Humidity related changes will be only effective after a
672 write operation to ctrl_meas register */
673 if (rslt == BME280_OK) {
674 reg_addr = BME280_CTRL_MEAS_ADDR;
675 rslt = bme280_get_regs(reg_addr, &ctrl_meas, 1, dev);
676 if (rslt == BME280_OK)
677 rslt = bme280_set_regs(®_addr, &ctrl_meas, 1, dev);
684 * @brief This API sets the pressure and/or temperature oversampling settings
685 * in the sensor according to the settings selected by the user.
687 static int8_t set_osr_press_temp_settings(uint8_t desired_settings, const struct bme280_settings *settings,
688 const struct bme280_dev *dev)
691 uint8_t reg_addr = BME280_CTRL_MEAS_ADDR;
694 rslt = bme280_get_regs(reg_addr, ®_data, 1, dev);
696 if (rslt == BME280_OK) {
697 if (desired_settings & BME280_OSR_PRESS_SEL)
698 fill_osr_press_settings(®_data, settings);
699 if (desired_settings & BME280_OSR_TEMP_SEL)
700 fill_osr_temp_settings(®_data, settings);
701 /* Write the oversampling settings in the register */
702 rslt = bme280_set_regs(®_addr, ®_data, 1, dev);
709 * @brief This internal API sets the filter and/or standby duration settings
710 * in the sensor according to the settings selected by the user.
712 static int8_t set_filter_standby_settings(uint8_t desired_settings, const struct bme280_settings *settings,
713 const struct bme280_dev *dev)
716 uint8_t reg_addr = BME280_CONFIG_ADDR;
719 rslt = bme280_get_regs(reg_addr, ®_data, 1, dev);
721 if (rslt == BME280_OK) {
722 if (desired_settings & BME280_FILTER_SEL)
723 fill_filter_settings(®_data, settings);
724 if (desired_settings & BME280_STANDBY_SEL)
725 fill_standby_settings(®_data, settings);
726 /* Write the oversampling settings in the register */
727 rslt = bme280_set_regs(®_addr, ®_data, 1, dev);
734 * @brief This internal API fills the filter settings provided by the user
735 * in the data buffer so as to write in the sensor.
737 static void fill_filter_settings(uint8_t *reg_data, const struct bme280_settings *settings)
739 *reg_data = BME280_SET_BITS(*reg_data, BME280_FILTER, settings->filter);
743 * @brief This internal API fills the standby duration settings provided by
744 * the user in the data buffer so as to write in the sensor.
746 static void fill_standby_settings(uint8_t *reg_data, const struct bme280_settings *settings)
748 *reg_data = BME280_SET_BITS(*reg_data, BME280_STANDBY, settings->standby_time);
752 * @brief This internal API fills the pressure oversampling settings provided by
753 * the user in the data buffer so as to write in the sensor.
755 static void fill_osr_press_settings(uint8_t *reg_data, const struct bme280_settings *settings)
757 *reg_data = BME280_SET_BITS(*reg_data, BME280_CTRL_PRESS, settings->osr_p);
761 * @brief This internal API fills the temperature oversampling settings
762 * provided by the user in the data buffer so as to write in the sensor.
764 static void fill_osr_temp_settings(uint8_t *reg_data, const struct bme280_settings *settings)
766 *reg_data = BME280_SET_BITS(*reg_data, BME280_CTRL_TEMP, settings->osr_t);
770 * @brief This internal API parse the oversampling(pressure, temperature
771 * and humidity), filter and standby duration settings and store in the
774 static void parse_device_settings(const uint8_t *reg_data, struct bme280_settings *settings)
776 settings->osr_h = BME280_GET_BITS_POS_0(reg_data[0], BME280_CTRL_HUM);
777 settings->osr_p = BME280_GET_BITS(reg_data[2], BME280_CTRL_PRESS);
778 settings->osr_t = BME280_GET_BITS(reg_data[2], BME280_CTRL_TEMP);
779 settings->filter = BME280_GET_BITS(reg_data[3], BME280_FILTER);
780 settings->standby_time = BME280_GET_BITS(reg_data[3], BME280_STANDBY);
783 * @brief This internal API writes the power mode in the sensor.
785 static int8_t write_power_mode(uint8_t sensor_mode, const struct bme280_dev *dev)
788 uint8_t reg_addr = BME280_PWR_CTRL_ADDR;
789 /* Variable to store the value read from power mode register */
790 uint8_t sensor_mode_reg_val;
792 /* Read the power mode register */
793 rslt = bme280_get_regs(reg_addr, &sensor_mode_reg_val, 1, dev);
794 /* Set the power mode */
795 if (rslt == BME280_OK) {
796 sensor_mode_reg_val = BME280_SET_BITS_POS_0(sensor_mode_reg_val, BME280_SENSOR_MODE, sensor_mode);
797 /* Write the power mode in the register */
798 rslt = bme280_set_regs(®_addr, &sensor_mode_reg_val, 1, dev);
805 * @brief This internal API puts the device to sleep mode.
807 static int8_t put_device_to_sleep(const struct bme280_dev *dev)
811 struct bme280_settings settings;
813 rslt = bme280_get_regs(BME280_CTRL_HUM_ADDR, reg_data, 4, dev);
814 if (rslt == BME280_OK) {
815 parse_device_settings(reg_data, &settings);
816 rslt = bme280_soft_reset(dev);
817 if (rslt == BME280_OK)
818 rslt = reload_device_settings(&settings, dev);
825 * @brief This internal API reloads the already existing device settings in
826 * the sensor after soft reset.
828 static int8_t reload_device_settings(const struct bme280_settings *settings, const struct bme280_dev *dev)
832 rslt = set_osr_settings(BME280_ALL_SETTINGS_SEL, settings, dev);
833 if (rslt == BME280_OK)
834 rslt = set_filter_standby_settings(BME280_ALL_SETTINGS_SEL, settings, dev);
840 * @brief This internal API is used to parse the pressure, temperature and
841 * humidity data and store it in the bme280_uncomp_data structure instance.
843 static void parse_sensor_data(const uint8_t *reg_data, struct bme280_uncomp_data *uncomp_data)
845 /* Variables to store the sensor data */
850 /* Store the parsed register values for pressure data */
851 data_xlsb = (uint32_t)reg_data[0] << 12;
852 data_lsb = (uint32_t)reg_data[1] << 4;
853 data_msb = (uint32_t)reg_data[2] << 4;
854 uncomp_data->pressure = data_msb | data_lsb | data_xlsb;
856 /* Store the parsed register values for temperature data */
857 data_xlsb = (uint32_t)reg_data[3] << 12;
858 data_lsb = (uint32_t)reg_data[4] << 4;
859 data_msb = (uint32_t)reg_data[5] << 4;
860 uncomp_data->temperature = data_msb | data_lsb | data_xlsb;
862 /* Store the parsed register values for temperature data */
863 data_lsb = (uint32_t)reg_data[6] << 8;
864 data_msb = (uint32_t)reg_data[7];
865 uncomp_data->humidity = data_msb | data_lsb;
869 * @brief This internal API is used to compensate the pressure and/or
870 * temperature and/or humidity data according to the component selected
873 static int8_t compensate_data(uint8_t sensor_comp, const struct bme280_uncomp_data *uncomp_data,
874 struct bme280_data *comp_data, struct bme280_calib_data *calib_data)
876 int8_t rslt = BME280_OK;
878 if ((uncomp_data != NULL) && (comp_data != NULL) && (calib_data != NULL)) {
879 /* Initialize to zero */
880 comp_data->temperature = 0;
881 comp_data->pressure = 0;
882 comp_data->humidity = 0;
883 /* If pressure or temperature component is selected */
884 if (sensor_comp & (BME280_PRESS | BME280_TEMP | BME280_HUM)) {
885 /* Compensate the temperature data */
886 comp_data->temperature = compensate_temperature(uncomp_data, calib_data);
888 if (sensor_comp & BME280_PRESS) {
889 /* Compensate the pressure data */
890 comp_data->pressure = compensate_pressure(uncomp_data, calib_data);
892 if (sensor_comp & BME280_HUM) {
893 /* Compensate the humidity data */
894 comp_data->humidity = compensate_humidity(uncomp_data, calib_data);
897 rslt = BME280_E_NULL_PTR;
903 #ifdef FLOATING_POINT_REPRESENTATION
905 * @brief This internal API is used to compensate the raw temperature data and
906 * return the compensated temperature data in double data type.
908 static double compensate_temperature(const struct bme280_uncomp_data *uncomp_data,
909 struct bme280_calib_data *calib_data)
914 double temperature_min = -40;
915 double temperature_max = 85;
917 var1 = ((double)uncomp_data->temperature) / 16384.0 - ((double)calib_data->dig_T1) / 1024.0;
918 var1 = var1 * ((double)calib_data->dig_T2);
919 var2 = (((double)uncomp_data->temperature) / 131072.0 - ((double)calib_data->dig_T1) / 8192.0);
920 var2 = (var2 * var2) * ((double)calib_data->dig_T3);
921 calib_data->t_fine = (int32_t)(var1 + var2);
922 temperature = (var1 + var2) / 5120.0;
924 if (temperature < temperature_min)
925 temperature = temperature_min;
926 else if (temperature > temperature_max)
927 temperature = temperature_max;
933 * @brief This internal API is used to compensate the raw pressure data and
934 * return the compensated pressure data in double data type.
936 static double compensate_pressure(const struct bme280_uncomp_data *uncomp_data,
937 const struct bme280_calib_data *calib_data)
943 double pressure_min = 30000.0;
944 double pressure_max = 110000.0;
946 var1 = ((double)calib_data->t_fine / 2.0) - 64000.0;
947 var2 = var1 * var1 * ((double)calib_data->dig_P6) / 32768.0;
948 var2 = var2 + var1 * ((double)calib_data->dig_P5) * 2.0;
949 var2 = (var2 / 4.0) + (((double)calib_data->dig_P4) * 65536.0);
950 var3 = ((double)calib_data->dig_P3) * var1 * var1 / 524288.0;
951 var1 = (var3 + ((double)calib_data->dig_P2) * var1) / 524288.0;
952 var1 = (1.0 + var1 / 32768.0) * ((double)calib_data->dig_P1);
953 /* avoid exception caused by division by zero */
955 pressure = 1048576.0 - (double) uncomp_data->pressure;
956 pressure = (pressure - (var2 / 4096.0)) * 6250.0 / var1;
957 var1 = ((double)calib_data->dig_P9) * pressure * pressure / 2147483648.0;
958 var2 = pressure * ((double)calib_data->dig_P8) / 32768.0;
959 pressure = pressure + (var1 + var2 + ((double)calib_data->dig_P7)) / 16.0;
961 if (pressure < pressure_min)
962 pressure = pressure_min;
963 else if (pressure > pressure_max)
964 pressure = pressure_max;
965 } else { /* Invalid case */
966 pressure = pressure_min;
973 * @brief This internal API is used to compensate the raw humidity data and
974 * return the compensated humidity data in double data type.
976 static double compensate_humidity(const struct bme280_uncomp_data *uncomp_data,
977 const struct bme280_calib_data *calib_data)
980 double humidity_min = 0.0;
981 double humidity_max = 100.0;
989 var1 = ((double)calib_data->t_fine) - 76800.0;
990 var2 = (((double)calib_data->dig_H4) * 64.0 + (((double)calib_data->dig_H5) / 16384.0) * var1);
991 var3 = uncomp_data->humidity - var2;
992 var4 = ((double)calib_data->dig_H2) / 65536.0;
993 var5 = (1.0 + (((double)calib_data->dig_H3) / 67108864.0) * var1);
994 var6 = 1.0 + (((double)calib_data->dig_H6) / 67108864.0) * var1 * var5;
995 var6 = var3 * var4 * (var5 * var6);
996 humidity = var6 * (1.0 - ((double)calib_data->dig_H1) * var6 / 524288.0);
998 if (humidity > humidity_max)
999 humidity = humidity_max;
1000 else if (humidity < humidity_min)
1001 humidity = humidity_min;
1008 * @brief This internal API is used to compensate the raw temperature data and
1009 * return the compensated temperature data in integer data type.
1011 static int32_t compensate_temperature(const struct bme280_uncomp_data *uncomp_data,
1012 struct bme280_calib_data *calib_data)
1016 int32_t temperature;
1017 int32_t temperature_min = -4000;
1018 int32_t temperature_max = 8500;
1020 var1 = (int32_t)((uncomp_data->temperature / 8) - ((int32_t)calib_data->dig_T1 * 2));
1021 var1 = (var1 * ((int32_t)calib_data->dig_T2)) / 2048;
1022 var2 = (int32_t)((uncomp_data->temperature / 16) - ((int32_t)calib_data->dig_T1));
1023 var2 = (((var2 * var2) / 4096) * ((int32_t)calib_data->dig_T3)) / 16384;
1024 calib_data->t_fine = var1 + var2;
1025 temperature = (calib_data->t_fine * 5 + 128) / 256;
1027 if (temperature < temperature_min)
1028 temperature = temperature_min;
1029 else if (temperature > temperature_max)
1030 temperature = temperature_max;
1034 #ifdef MACHINE_64_BIT
1036 * @brief This internal API is used to compensate the raw pressure data and
1037 * return the compensated pressure data in integer data type with higher
1040 static uint32_t compensate_pressure(const struct bme280_uncomp_data *uncomp_data,
1041 const struct bme280_calib_data *calib_data)
1048 uint32_t pressure_min = 3000000;
1049 uint32_t pressure_max = 11000000;
1051 var1 = ((int64_t)calib_data->t_fine) - 128000;
1052 var2 = var1 * var1 * (int64_t)calib_data->dig_P6;
1053 var2 = var2 + ((var1 * (int64_t)calib_data->dig_P5) * 131072);
1054 var2 = var2 + (((int64_t)calib_data->dig_P4) * 34359738368);
1055 var1 = ((var1 * var1 * (int64_t)calib_data->dig_P3) / 256) + ((var1 * (int64_t)calib_data->dig_P2) * 4096);
1056 var3 = ((int64_t)1) * 140737488355328;
1057 var1 = (var3 + var1) * ((int64_t)calib_data->dig_P1) / 8589934592;
1059 /* To avoid divide by zero exception */
1061 var4 = 1048576 - uncomp_data->pressure;
1062 var4 = (((var4 * (2147483648UL)) - var2) * 3125) / var1;
1063 var1 = (((int64_t)calib_data->dig_P9) * (var4 / 8192) * (var4 / 8192)) / 33554432;
1064 var2 = (((int64_t)calib_data->dig_P8) * var4) / 524288;
1065 var4 = ((var4 + var1 + var2) / 256) + (((int64_t)calib_data->dig_P7) * 16);
1066 pressure = (uint32_t)(((var4 / 2) * 100) / 128);
1068 if (pressure < pressure_min)
1069 pressure = pressure_min;
1070 else if (pressure > pressure_max)
1071 pressure = pressure_max;
1073 pressure = pressure_min;
1080 * @brief This internal API is used to compensate the raw pressure data and
1081 * return the compensated pressure data in integer data type.
1083 static uint32_t compensate_pressure(const struct bme280_uncomp_data *uncomp_data,
1084 const struct bme280_calib_data *calib_data)
1092 uint32_t pressure_min = 30000;
1093 uint32_t pressure_max = 110000;
1095 var1 = (((int32_t)calib_data->t_fine) / 2) - (int32_t)64000;
1096 var2 = (((var1 / 4) * (var1 / 4)) / 2048) * ((int32_t)calib_data->dig_P6);
1097 var2 = var2 + ((var1 * ((int32_t)calib_data->dig_P5)) * 2);
1098 var2 = (var2 / 4) + (((int32_t)calib_data->dig_P4) * 65536);
1099 var3 = (calib_data->dig_P3 * (((var1 / 4) * (var1 / 4)) / 8192)) / 8;
1100 var4 = (((int32_t)calib_data->dig_P2) * var1) / 2;
1101 var1 = (var3 + var4) / 262144;
1102 var1 = (((32768 + var1)) * ((int32_t)calib_data->dig_P1)) / 32768;
1103 /* avoid exception caused by division by zero */
1105 var5 = (uint32_t)((uint32_t)1048576) - uncomp_data->pressure;
1106 pressure = ((uint32_t)(var5 - (uint32_t)(var2 / 4096))) * 3125;
1107 if (pressure < 0x80000000)
1108 pressure = (pressure << 1) / ((uint32_t)var1);
1110 pressure = (pressure / (uint32_t)var1) * 2;
1112 var1 = (((int32_t)calib_data->dig_P9) * ((int32_t)(((pressure / 8) * (pressure / 8)) / 8192))) / 4096;
1113 var2 = (((int32_t)(pressure / 4)) * ((int32_t)calib_data->dig_P8)) / 8192;
1114 pressure = (uint32_t)((int32_t)pressure + ((var1 + var2 + calib_data->dig_P7) / 16));
1116 if (pressure < pressure_min)
1117 pressure = pressure_min;
1118 else if (pressure > pressure_max)
1119 pressure = pressure_max;
1121 pressure = pressure_min;
1129 * @brief This internal API is used to compensate the raw humidity data and
1130 * return the compensated humidity data in integer data type.
1132 static uint32_t compensate_humidity(const struct bme280_uncomp_data *uncomp_data,
1133 const struct bme280_calib_data *calib_data)
1141 uint32_t humidity_max = 100000;
1143 var1 = calib_data->t_fine - ((int32_t)76800);
1144 var2 = (int32_t)(uncomp_data->humidity * 16384);
1145 var3 = (int32_t)(((int32_t)calib_data->dig_H4) * 1048576);
1146 var4 = ((int32_t)calib_data->dig_H5) * var1;
1147 var5 = (((var2 - var3) - var4) + (int32_t)16384) / 32768;
1148 var2 = (var1 * ((int32_t)calib_data->dig_H6)) / 1024;
1149 var3 = (var1 * ((int32_t)calib_data->dig_H3)) / 2048;
1150 var4 = ((var2 * (var3 + (int32_t)32768)) / 1024) + (int32_t)2097152;
1151 var2 = ((var4 * ((int32_t)calib_data->dig_H2)) + 8192) / 16384;
1153 var4 = ((var3 / 32768) * (var3 / 32768)) / 128;
1154 var5 = var3 - ((var4 * ((int32_t)calib_data->dig_H1)) / 16);
1155 var5 = (var5 < 0 ? 0 : var5);
1156 var5 = (var5 > 419430400 ? 419430400 : var5);
1157 humidity = (uint32_t)(var5 / 4096);
1159 if (humidity > humidity_max)
1160 humidity = humidity_max;
1167 * @brief This internal API reads the calibration data from the sensor, parse
1168 * it and store in the device structure.
1170 static int8_t get_calib_data(struct bme280_dev *dev)
1173 uint8_t reg_addr = BME280_TEMP_PRESS_CALIB_DATA_ADDR;
1174 /* Array to store calibration data */
1175 uint8_t calib_data[BME280_TEMP_PRESS_CALIB_DATA_LEN] = {0};
1177 /* Read the calibration data from the sensor */
1178 rslt = bme280_get_regs(reg_addr, calib_data, BME280_TEMP_PRESS_CALIB_DATA_LEN, dev);
1180 if (rslt == BME280_OK) {
1181 /* Parse temperature and pressure calibration data and store
1182 it in device structure */
1183 parse_temp_press_calib_data(calib_data, dev);
1185 reg_addr = BME280_HUMIDITY_CALIB_DATA_ADDR;
1186 /* Read the humidity calibration data from the sensor */
1187 rslt = bme280_get_regs(reg_addr, calib_data, BME280_HUMIDITY_CALIB_DATA_LEN, dev);
1188 if (rslt == BME280_OK) {
1189 /* Parse humidity calibration data and store it in
1191 parse_humidity_calib_data(calib_data, dev);
1199 * @brief This internal API interleaves the register address between the
1200 * register data buffer for burst write operation.
1202 static void interleave_reg_addr(const uint8_t *reg_addr, uint8_t *temp_buff, const uint8_t *reg_data, uint8_t len)
1206 for (index = 1; index < len; index++) {
1207 temp_buff[(index * 2) - 1] = reg_addr[index];
1208 temp_buff[index * 2] = reg_data[index];
1213 * @brief This internal API is used to parse the temperature and
1214 * pressure calibration data and store it in device structure.
1216 static void parse_temp_press_calib_data(const uint8_t *reg_data, struct bme280_dev *dev)
1218 struct bme280_calib_data *calib_data = &dev->calib_data;
1220 calib_data->dig_T1 = BME280_CONCAT_BYTES(reg_data[1], reg_data[0]);
1221 calib_data->dig_T2 = (int16_t)BME280_CONCAT_BYTES(reg_data[3], reg_data[2]);
1222 calib_data->dig_T3 = (int16_t)BME280_CONCAT_BYTES(reg_data[5], reg_data[4]);
1223 calib_data->dig_P1 = BME280_CONCAT_BYTES(reg_data[7], reg_data[6]);
1224 calib_data->dig_P2 = (int16_t)BME280_CONCAT_BYTES(reg_data[9], reg_data[8]);
1225 calib_data->dig_P3 = (int16_t)BME280_CONCAT_BYTES(reg_data[11], reg_data[10]);
1226 calib_data->dig_P4 = (int16_t)BME280_CONCAT_BYTES(reg_data[13], reg_data[12]);
1227 calib_data->dig_P5 = (int16_t)BME280_CONCAT_BYTES(reg_data[15], reg_data[14]);
1228 calib_data->dig_P6 = (int16_t)BME280_CONCAT_BYTES(reg_data[17], reg_data[16]);
1229 calib_data->dig_P7 = (int16_t)BME280_CONCAT_BYTES(reg_data[19], reg_data[18]);
1230 calib_data->dig_P8 = (int16_t)BME280_CONCAT_BYTES(reg_data[21], reg_data[20]);
1231 calib_data->dig_P9 = (int16_t)BME280_CONCAT_BYTES(reg_data[23], reg_data[22]);
1232 calib_data->dig_H1 = reg_data[25];
1237 * @brief This internal API is used to parse the humidity calibration data
1238 * and store it in device structure.
1240 static void parse_humidity_calib_data(const uint8_t *reg_data, struct bme280_dev *dev)
1242 struct bme280_calib_data *calib_data = &dev->calib_data;
1248 calib_data->dig_H2 = (int16_t)BME280_CONCAT_BYTES(reg_data[1], reg_data[0]);
1249 calib_data->dig_H3 = reg_data[2];
1251 dig_H4_msb = (int16_t)(int8_t)reg_data[3] * 16;
1252 dig_H4_lsb = (int16_t)(reg_data[4] & 0x0F);
1253 calib_data->dig_H4 = dig_H4_msb | dig_H4_lsb;
1255 dig_H5_msb = (int16_t)(int8_t)reg_data[5] * 16;
1256 dig_H5_lsb = (int16_t)(reg_data[4] >> 4);
1257 calib_data->dig_H5 = dig_H5_msb | dig_H5_lsb;
1258 calib_data->dig_H6 = (int8_t)reg_data[6];
1262 * @brief This internal API is used to identify the settings which the user
1263 * wants to modify in the sensor.
1265 static uint8_t are_settings_changed(uint8_t sub_settings, uint8_t desired_settings)
1267 uint8_t settings_changed = FALSE;
1269 if (sub_settings & desired_settings) {
1270 /* User wants to modify this particular settings */
1271 settings_changed = TRUE;
1273 /* User don't want to modify this particular settings */
1274 settings_changed = FALSE;
1277 return settings_changed;
1281 * @brief This internal API is used to validate the device structure pointer for
1284 static int8_t null_ptr_check(const struct bme280_dev *dev)
1288 if ((dev == NULL) || (dev->read == NULL) || (dev->write == NULL) || (dev->delay_ms == NULL)) {
1289 /* Device structure pointer is not valid */
1290 rslt = BME280_E_NULL_PTR;
1292 /* Device structure is fine */