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49 * @brief Sensor driver for BME280 sensor
53 /**\name Internal macros */
54 /* To identify osr settings selected by user */
55 #define OVERSAMPLING_SETTINGS UINT8_C(0x07)
57 /* To identify filter and standby settings selected by user */
58 #define FILTER_STANDBY_SETTINGS UINT8_C(0x18)
61 * @brief This internal API puts the device to sleep mode.
63 * @param[in] dev : Structure instance of bme280_dev.
65 * @return Result of API execution status.
66 * @retval zero -> Success / +ve value -> Warning / -ve value -> Error
68 static int8_t put_device_to_sleep(const struct bme280_dev *dev);
71 * @brief This internal API writes the power mode in the sensor.
73 * @param[in] dev : Structure instance of bme280_dev.
74 * @param[in] sensor_mode : Variable which contains the power mode to be set.
76 * @return Result of API execution status.
77 * @retval zero -> Success / +ve value -> Warning / -ve value -> Error
79 static int8_t write_power_mode(uint8_t sensor_mode, const struct bme280_dev *dev);
82 * @brief This internal API is used to validate the device pointer for
85 * @param[in] dev : Structure instance of bme280_dev.
87 * @return Result of API execution status
88 * @retval zero -> Success / +ve value -> Warning / -ve value -> Error
90 static int8_t null_ptr_check(const struct bme280_dev *dev);
93 * @brief This internal API interleaves the register address between the
94 * register data buffer for burst write operation.
96 * @param[in] reg_addr : Contains the register address array.
97 * @param[out] temp_buff : Contains the temporary buffer to store the
98 * register data and register address.
99 * @param[in] reg_data : Contains the register data to be written in the
101 * @param[in] len : No of bytes of data to be written for burst write.
103 static void interleave_reg_addr(const uint8_t *reg_addr, uint8_t *temp_buff, const uint8_t *reg_data, uint8_t len);
106 * @brief This internal API reads the calibration data from the sensor, parse
107 * it and store in the device structure.
109 * @param[in] dev : Structure instance of bme280_dev.
111 * @return Result of API execution status
112 * @retval zero -> Success / +ve value -> Warning / -ve value -> Error
114 static int8_t get_calib_data(struct bme280_dev *dev);
117 * @brief This internal API is used to parse the temperature and
118 * pressure calibration data and store it in the device structure.
120 * @param[out] dev : Structure instance of bme280_dev to store the calib data.
121 * @param[in] reg_data : Contains the calibration data to be parsed.
123 static void parse_temp_press_calib_data(const uint8_t *reg_data, struct bme280_dev *dev);
126 * @brief This internal API is used to parse the humidity calibration data
127 * and store it in device structure.
129 * @param[out] dev : Structure instance of bme280_dev to store the calib data.
130 * @param[in] reg_data : Contains calibration data to be parsed.
132 static void parse_humidity_calib_data(const uint8_t *reg_data, struct bme280_dev *dev);
134 #ifdef BME280_FLOAT_ENABLE
137 * @brief This internal API is used to compensate the raw pressure data and
138 * return the compensated pressure data in double data type.
140 * @param[in] uncomp_data : Contains the uncompensated pressure data.
141 * @param[in] calib_data : Pointer to the calibration data structure.
143 * @return Compensated pressure data.
144 * @retval Compensated pressure data in double.
146 static double compensate_pressure(const struct bme280_uncomp_data *uncomp_data,
147 const struct bme280_calib_data *calib_data);
150 * @brief This internal API is used to compensate the raw humidity data and
151 * return the compensated humidity data in double data type.
153 * @param[in] uncomp_data : Contains the uncompensated humidity data.
154 * @param[in] calib_data : Pointer to the calibration data structure.
156 * @return Compensated humidity data.
157 * @retval Compensated humidity data in double.
159 static double compensate_humidity(const struct bme280_uncomp_data *uncomp_data,
160 const struct bme280_calib_data *calib_data);
163 * @brief This internal API is used to compensate the raw temperature data and
164 * return the compensated temperature data in double data type.
166 * @param[in] uncomp_data : Contains the uncompensated temperature data.
167 * @param[in] calib_data : Pointer to calibration data structure.
169 * @return Compensated temperature data.
170 * @retval Compensated temperature data in double.
172 static double compensate_temperature(const struct bme280_uncomp_data *uncomp_data,
173 struct bme280_calib_data *calib_data);
178 * @brief This internal API is used to compensate the raw temperature data and
179 * return the compensated temperature data in integer data type.
181 * @param[in] uncomp_data : Contains the uncompensated temperature data.
182 * @param[in] calib_data : Pointer to calibration data structure.
184 * @return Compensated temperature data.
185 * @retval Compensated temperature data in integer.
187 static int32_t compensate_temperature(const struct bme280_uncomp_data *uncomp_data,
188 struct bme280_calib_data *calib_data);
191 * @brief This internal API is used to compensate the raw pressure data and
192 * return the compensated pressure data in integer data type.
194 * @param[in] uncomp_data : Contains the uncompensated pressure data.
195 * @param[in] calib_data : Pointer to the calibration data structure.
197 * @return Compensated pressure data.
198 * @retval Compensated pressure data in integer.
200 static uint32_t compensate_pressure(const struct bme280_uncomp_data *uncomp_data,
201 const struct bme280_calib_data *calib_data);
204 * @brief This internal API is used to compensate the raw humidity data and
205 * return the compensated humidity data in integer data type.
207 * @param[in] uncomp_data : Contains the uncompensated humidity data.
208 * @param[in] calib_data : Pointer to the calibration data structure.
210 * @return Compensated humidity data.
211 * @retval Compensated humidity data in integer.
213 static uint32_t compensate_humidity(const struct bme280_uncomp_data *uncomp_data,
214 const struct bme280_calib_data *calib_data);
219 * @brief This internal API is used to identify the settings which the user
220 * wants to modify in the sensor.
222 * @param[in] sub_settings : Contains the settings subset to identify particular
223 * group of settings which the user is interested to change.
224 * @param[in] desired_settings : Contains the user specified settings.
226 * @return Indicates whether user is interested to modify the settings which
227 * are related to sub_settings.
228 * @retval True -> User wants to modify this group of settings
229 * @retval False -> User does not want to modify this group of settings
231 static uint8_t are_settings_changed(uint8_t sub_settings, uint8_t desired_settings);
234 * @brief This API sets the humidity oversampling settings of the sensor.
236 * @param[in] dev : Structure instance of bme280_dev.
238 * @return Result of API execution status
239 * @retval zero -> Success / +ve value -> Warning / -ve value -> Error
241 static int8_t set_osr_humidity_settings(const struct bme280_settings *settings, const struct bme280_dev *dev);
244 * @brief This internal API sets the oversampling settings for pressure,
245 * temperature and humidity in the sensor.
247 * @param[in] desired_settings : Variable used to select the settings which
249 * @param[in] dev : Structure instance of bme280_dev.
251 * @return Result of API execution status
252 * @retval zero -> Success / +ve value -> Warning / -ve value -> Error
254 static int8_t set_osr_settings(uint8_t desired_settings,
255 const struct bme280_settings *settings,
256 const struct bme280_dev *dev);
259 * @brief This API sets the pressure and/or temperature oversampling settings
260 * in the sensor according to the settings selected by the user.
262 * @param[in] dev : Structure instance of bme280_dev.
263 * @param[in] desired_settings: variable to select the pressure and/or
264 * temperature oversampling settings.
266 * @return Result of API execution status
267 * @retval zero -> Success / +ve value -> Warning / -ve value -> Error
269 static int8_t set_osr_press_temp_settings(uint8_t desired_settings,
270 const struct bme280_settings *settings,
271 const struct bme280_dev *dev);
274 * @brief This internal API fills the pressure oversampling settings provided by
275 * the user in the data buffer so as to write in the sensor.
277 * @param[in] dev : Structure instance of bme280_dev.
278 * @param[out] reg_data : Variable which is filled according to the pressure
279 * oversampling data provided by the user.
281 static void fill_osr_press_settings(uint8_t *reg_data, const struct bme280_settings *settings);
284 * @brief This internal API fills the temperature oversampling settings provided
285 * by the user in the data buffer so as to write in the sensor.
287 * @param[in] dev : Structure instance of bme280_dev.
288 * @param[out] reg_data : Variable which is filled according to the temperature
289 * oversampling data provided by the user.
291 static void fill_osr_temp_settings(uint8_t *reg_data, const struct bme280_settings *settings);
294 * @brief This internal API sets the filter and/or standby duration settings
295 * in the sensor according to the settings selected by the user.
297 * @param[in] dev : Structure instance of bme280_dev.
298 * @param[in] desired_settings : variable to select the filter and/or
299 * standby duration settings.
301 * @return Result of API execution status
302 * @retval zero -> Success / +ve value -> Warning / -ve value -> Error
304 static int8_t set_filter_standby_settings(uint8_t desired_settings,
305 const struct bme280_settings *settings,
306 const struct bme280_dev *dev);
309 * @brief This internal API fills the filter settings provided by the user
310 * in the data buffer so as to write in the sensor.
312 * @param[in] dev : Structure instance of bme280_dev.
313 * @param[out] reg_data : Variable which is filled according to the filter
314 * settings data provided by the user.
316 static void fill_filter_settings(uint8_t *reg_data, const struct bme280_settings *settings);
319 * @brief This internal API fills the standby duration settings provided by the
320 * user in the data buffer so as to write in the sensor.
322 * @param[in] dev : Structure instance of bme280_dev.
323 * @param[out] reg_data : Variable which is filled according to the standby
324 * settings data provided by the user.
326 static void fill_standby_settings(uint8_t *reg_data, const struct bme280_settings *settings);
329 * @brief This internal API parse the oversampling(pressure, temperature
330 * and humidity), filter and standby duration settings and store in the
333 * @param[out] dev : Structure instance of bme280_dev.
334 * @param[in] reg_data : Register data to be parsed.
336 static void parse_device_settings(const uint8_t *reg_data, struct bme280_settings *settings);
339 * @brief This internal API reloads the already existing device settings in the
340 * sensor after soft reset.
342 * @param[in] dev : Structure instance of bme280_dev.
343 * @param[in] settings : Pointer variable which contains the settings to
344 * be set in the sensor.
346 * @return Result of API execution status
347 * @retval zero -> Success / +ve value -> Warning / -ve value -> Error
349 static int8_t reload_device_settings(const struct bme280_settings *settings, const struct bme280_dev *dev);
351 /****************** Global Function Definitions *******************************/
354 * @brief This API is the entry point.
355 * It reads the chip-id and calibration data from the sensor.
357 int8_t bme280_init(struct bme280_dev *dev)
361 /* chip id read try count */
362 uint8_t try_count = 5;
365 /* Check for null pointer in the device structure*/
366 rslt = null_ptr_check(dev);
368 /* Proceed if null check is fine */
369 if (rslt == BME280_OK)
373 /* Read the chip-id of bme280 sensor */
374 rslt = bme280_get_regs(BME280_CHIP_ID_ADDR, &chip_id, 1, dev);
376 /* Check for chip id validity */
377 if ((rslt == BME280_OK) && (chip_id == BME280_CHIP_ID))
379 dev->chip_id = chip_id;
381 /* Reset the sensor */
382 rslt = bme280_soft_reset(dev);
383 if (rslt == BME280_OK)
385 /* Read the calibration data */
386 rslt = get_calib_data(dev);
396 /* Chip id check failed */
399 rslt = BME280_E_DEV_NOT_FOUND;
407 * @brief This API reads the data from the given register address of the sensor.
409 int8_t bme280_get_regs(uint8_t reg_addr, uint8_t *reg_data, uint16_t len, const struct bme280_dev *dev)
413 /* Check for null pointer in the device structure*/
414 rslt = null_ptr_check(dev);
416 /* Proceed if null check is fine */
417 if (rslt == BME280_OK)
419 /* If interface selected is SPI */
420 if (dev->intf != BME280_I2C_INTF)
422 reg_addr = reg_addr | 0x80;
426 rslt = dev->read(dev->dev_id, reg_addr, reg_data, len);
428 /* Check for communication error */
429 if (rslt != BME280_OK)
431 rslt = BME280_E_COMM_FAIL;
439 * @brief This API writes the given data to the register address
442 int8_t bme280_set_regs(uint8_t *reg_addr, const uint8_t *reg_data, uint8_t len, const struct bme280_dev *dev)
445 uint8_t temp_buff[20]; /* Typically not to write more than 10 registers */
452 uint8_t reg_addr_cnt;
454 /* Check for null pointer in the device structure*/
455 rslt = null_ptr_check(dev);
457 /* Check for arguments validity */
458 if ((rslt == BME280_OK) && (reg_addr != NULL) && (reg_data != NULL))
462 temp_buff[0] = reg_data[0];
464 /* If interface selected is SPI */
465 if (dev->intf != BME280_I2C_INTF)
467 for (reg_addr_cnt = 0; reg_addr_cnt < len; reg_addr_cnt++)
469 reg_addr[reg_addr_cnt] = reg_addr[reg_addr_cnt] & 0x7F;
473 /* Burst write mode */
476 /* Interleave register address w.r.t data for
479 interleave_reg_addr(reg_addr, temp_buff, reg_data, len);
480 temp_len = ((len * 2) - 1);
486 rslt = dev->write(dev->dev_id, reg_addr[0], temp_buff, temp_len);
488 /* Check for communication error */
489 if (rslt != BME280_OK)
491 rslt = BME280_E_COMM_FAIL;
496 rslt = BME280_E_INVALID_LEN;
501 rslt = BME280_E_NULL_PTR;
508 * @brief This API sets the oversampling, filter and standby duration
509 * (normal mode) settings in the sensor.
511 int8_t bme280_set_sensor_settings(uint8_t desired_settings, const struct bme280_dev *dev)
516 /* Check for null pointer in the device structure*/
517 rslt = null_ptr_check(dev);
519 /* Proceed if null check is fine */
520 if (rslt == BME280_OK)
522 rslt = bme280_get_sensor_mode(&sensor_mode, dev);
523 if ((rslt == BME280_OK) && (sensor_mode != BME280_SLEEP_MODE))
525 rslt = put_device_to_sleep(dev);
527 if (rslt == BME280_OK)
529 /* Check if user wants to change oversampling
532 if (are_settings_changed(OVERSAMPLING_SETTINGS, desired_settings))
534 rslt = set_osr_settings(desired_settings, &dev->settings, dev);
537 /* Check if user wants to change filter and/or
540 if ((rslt == BME280_OK) && are_settings_changed(FILTER_STANDBY_SETTINGS, desired_settings))
542 rslt = set_filter_standby_settings(desired_settings, &dev->settings, dev);
551 * @brief This API gets the oversampling, filter and standby duration
552 * (normal mode) settings from the sensor.
554 int8_t bme280_get_sensor_settings(struct bme280_dev *dev)
559 /* Check for null pointer in the device structure*/
560 rslt = null_ptr_check(dev);
562 /* Proceed if null check is fine */
563 if (rslt == BME280_OK)
565 rslt = bme280_get_regs(BME280_CTRL_HUM_ADDR, reg_data, 4, dev);
566 if (rslt == BME280_OK)
568 parse_device_settings(reg_data, &dev->settings);
576 * @brief This API sets the power mode of the sensor.
578 int8_t bme280_set_sensor_mode(uint8_t sensor_mode, const struct bme280_dev *dev)
581 uint8_t last_set_mode;
583 /* Check for null pointer in the device structure*/
584 rslt = null_ptr_check(dev);
585 if (rslt == BME280_OK)
587 rslt = bme280_get_sensor_mode(&last_set_mode, dev);
589 /* If the sensor is not in sleep mode put the device to sleep
592 if ((rslt == BME280_OK) && (last_set_mode != BME280_SLEEP_MODE))
594 rslt = put_device_to_sleep(dev);
597 /* Set the power mode */
598 if (rslt == BME280_OK)
600 rslt = write_power_mode(sensor_mode, dev);
608 * @brief This API gets the power mode of the sensor.
610 int8_t bme280_get_sensor_mode(uint8_t *sensor_mode, const struct bme280_dev *dev)
614 /* Check for null pointer in the device structure*/
615 rslt = null_ptr_check(dev);
616 if (rslt == BME280_OK)
618 /* Read the power mode register */
619 rslt = bme280_get_regs(BME280_PWR_CTRL_ADDR, sensor_mode, 1, dev);
621 /* Assign the power mode in the device structure */
622 *sensor_mode = BME280_GET_BITS_POS_0(*sensor_mode, BME280_SENSOR_MODE);
629 * @brief This API performs the soft reset of the sensor.
631 int8_t bme280_soft_reset(const struct bme280_dev *dev)
634 uint8_t reg_addr = BME280_RESET_ADDR;
636 /* 0xB6 is the soft reset command */
637 uint8_t soft_rst_cmd = 0xB6;
639 /* Check for null pointer in the device structure*/
640 rslt = null_ptr_check(dev);
642 /* Proceed if null check is fine */
643 if (rslt == BME280_OK)
645 /* Write the soft reset command in the sensor */
646 rslt = bme280_set_regs(®_addr, &soft_rst_cmd, 1, dev);
648 /* As per data sheet, startup time is 2 ms. */
656 * @brief This API reads the pressure, temperature and humidity data from the
657 * sensor, compensates the data and store it in the bme280_data structure
658 * instance passed by the user.
660 int8_t bme280_get_sensor_data(uint8_t sensor_comp, struct bme280_data *comp_data, struct bme280_dev *dev)
664 /* Array to store the pressure, temperature and humidity data read from
667 uint8_t reg_data[BME280_P_T_H_DATA_LEN] = { 0 };
668 struct bme280_uncomp_data uncomp_data = { 0 };
670 /* Check for null pointer in the device structure*/
671 rslt = null_ptr_check(dev);
672 if ((rslt == BME280_OK) && (comp_data != NULL))
674 /* Read the pressure and temperature data from the sensor */
675 rslt = bme280_get_regs(BME280_DATA_ADDR, reg_data, BME280_P_T_H_DATA_LEN, dev);
676 if (rslt == BME280_OK)
678 /* Parse the read data from the sensor */
679 bme280_parse_sensor_data(reg_data, &uncomp_data);
681 /* Compensate the pressure and/or temperature and/or
682 * humidity data from the sensor
684 rslt = bme280_compensate_data(sensor_comp, &uncomp_data, comp_data, &dev->calib_data);
689 rslt = BME280_E_NULL_PTR;
696 * @brief This API is used to parse the pressure, temperature and
697 * humidity data and store it in the bme280_uncomp_data structure instance.
699 void bme280_parse_sensor_data(const uint8_t *reg_data, struct bme280_uncomp_data *uncomp_data)
701 /* Variables to store the sensor data */
706 /* Store the parsed register values for pressure data */
707 data_msb = (uint32_t)reg_data[0] << 12;
708 data_lsb = (uint32_t)reg_data[1] << 4;
709 data_xlsb = (uint32_t)reg_data[2] >> 4;
710 uncomp_data->pressure = data_msb | data_lsb | data_xlsb;
712 /* Store the parsed register values for temperature data */
713 data_msb = (uint32_t)reg_data[3] << 12;
714 data_lsb = (uint32_t)reg_data[4] << 4;
715 data_xlsb = (uint32_t)reg_data[5] >> 4;
716 uncomp_data->temperature = data_msb | data_lsb | data_xlsb;
718 /* Store the parsed register values for temperature data */
719 data_lsb = (uint32_t)reg_data[6] << 8;
720 data_msb = (uint32_t)reg_data[7];
721 uncomp_data->humidity = data_msb | data_lsb;
725 * @brief This API is used to compensate the pressure and/or
726 * temperature and/or humidity data according to the component selected
729 int8_t bme280_compensate_data(uint8_t sensor_comp,
730 const struct bme280_uncomp_data *uncomp_data,
731 struct bme280_data *comp_data,
732 struct bme280_calib_data *calib_data)
734 int8_t rslt = BME280_OK;
736 if ((uncomp_data != NULL) && (comp_data != NULL) && (calib_data != NULL))
738 /* Initialize to zero */
739 comp_data->temperature = 0;
740 comp_data->pressure = 0;
741 comp_data->humidity = 0;
743 /* If pressure or temperature component is selected */
744 if (sensor_comp & (BME280_PRESS | BME280_TEMP | BME280_HUM))
746 /* Compensate the temperature data */
747 comp_data->temperature = compensate_temperature(uncomp_data, calib_data);
749 if (sensor_comp & BME280_PRESS)
751 /* Compensate the pressure data */
752 comp_data->pressure = compensate_pressure(uncomp_data, calib_data);
754 if (sensor_comp & BME280_HUM)
756 /* Compensate the humidity data */
757 comp_data->humidity = compensate_humidity(uncomp_data, calib_data);
762 rslt = BME280_E_NULL_PTR;
769 * @brief This internal API sets the oversampling settings for pressure,
770 * temperature and humidity in the sensor.
772 static int8_t set_osr_settings(uint8_t desired_settings,
773 const struct bme280_settings *settings,
774 const struct bme280_dev *dev)
776 int8_t rslt = BME280_W_INVALID_OSR_MACRO;
778 if (desired_settings & BME280_OSR_HUM_SEL)
780 rslt = set_osr_humidity_settings(settings, dev);
782 if (desired_settings & (BME280_OSR_PRESS_SEL | BME280_OSR_TEMP_SEL))
784 rslt = set_osr_press_temp_settings(desired_settings, settings, dev);
791 * @brief This API sets the humidity oversampling settings of the sensor.
793 static int8_t set_osr_humidity_settings(const struct bme280_settings *settings, const struct bme280_dev *dev)
798 uint8_t reg_addr = BME280_CTRL_HUM_ADDR;
800 ctrl_hum = settings->osr_h & BME280_CTRL_HUM_MSK;
802 /* Write the humidity control value in the register */
803 rslt = bme280_set_regs(®_addr, &ctrl_hum, 1, dev);
805 /* Humidity related changes will be only effective after a
806 * write operation to ctrl_meas register
808 if (rslt == BME280_OK)
810 reg_addr = BME280_CTRL_MEAS_ADDR;
811 rslt = bme280_get_regs(reg_addr, &ctrl_meas, 1, dev);
812 if (rslt == BME280_OK)
814 rslt = bme280_set_regs(®_addr, &ctrl_meas, 1, dev);
822 * @brief This API sets the pressure and/or temperature oversampling settings
823 * in the sensor according to the settings selected by the user.
825 static int8_t set_osr_press_temp_settings(uint8_t desired_settings,
826 const struct bme280_settings *settings,
827 const struct bme280_dev *dev)
830 uint8_t reg_addr = BME280_CTRL_MEAS_ADDR;
833 rslt = bme280_get_regs(reg_addr, ®_data, 1, dev);
834 if (rslt == BME280_OK)
836 if (desired_settings & BME280_OSR_PRESS_SEL)
838 fill_osr_press_settings(®_data, settings);
840 if (desired_settings & BME280_OSR_TEMP_SEL)
842 fill_osr_temp_settings(®_data, settings);
845 /* Write the oversampling settings in the register */
846 rslt = bme280_set_regs(®_addr, ®_data, 1, dev);
853 * @brief This internal API sets the filter and/or standby duration settings
854 * in the sensor according to the settings selected by the user.
856 static int8_t set_filter_standby_settings(uint8_t desired_settings,
857 const struct bme280_settings *settings,
858 const struct bme280_dev *dev)
861 uint8_t reg_addr = BME280_CONFIG_ADDR;
864 rslt = bme280_get_regs(reg_addr, ®_data, 1, dev);
865 if (rslt == BME280_OK)
867 if (desired_settings & BME280_FILTER_SEL)
869 fill_filter_settings(®_data, settings);
871 if (desired_settings & BME280_STANDBY_SEL)
873 fill_standby_settings(®_data, settings);
876 /* Write the oversampling settings in the register */
877 rslt = bme280_set_regs(®_addr, ®_data, 1, dev);
884 * @brief This internal API fills the filter settings provided by the user
885 * in the data buffer so as to write in the sensor.
887 static void fill_filter_settings(uint8_t *reg_data, const struct bme280_settings *settings)
889 *reg_data = BME280_SET_BITS(*reg_data, BME280_FILTER, settings->filter);
893 * @brief This internal API fills the standby duration settings provided by
894 * the user in the data buffer so as to write in the sensor.
896 static void fill_standby_settings(uint8_t *reg_data, const struct bme280_settings *settings)
898 *reg_data = BME280_SET_BITS(*reg_data, BME280_STANDBY, settings->standby_time);
902 * @brief This internal API fills the pressure oversampling settings provided by
903 * the user in the data buffer so as to write in the sensor.
905 static void fill_osr_press_settings(uint8_t *reg_data, const struct bme280_settings *settings)
907 *reg_data = BME280_SET_BITS(*reg_data, BME280_CTRL_PRESS, settings->osr_p);
911 * @brief This internal API fills the temperature oversampling settings
912 * provided by the user in the data buffer so as to write in the sensor.
914 static void fill_osr_temp_settings(uint8_t *reg_data, const struct bme280_settings *settings)
916 *reg_data = BME280_SET_BITS(*reg_data, BME280_CTRL_TEMP, settings->osr_t);
920 * @brief This internal API parse the oversampling(pressure, temperature
921 * and humidity), filter and standby duration settings and store in the
924 static void parse_device_settings(const uint8_t *reg_data, struct bme280_settings *settings)
926 settings->osr_h = BME280_GET_BITS_POS_0(reg_data[0], BME280_CTRL_HUM);
927 settings->osr_p = BME280_GET_BITS(reg_data[2], BME280_CTRL_PRESS);
928 settings->osr_t = BME280_GET_BITS(reg_data[2], BME280_CTRL_TEMP);
929 settings->filter = BME280_GET_BITS(reg_data[3], BME280_FILTER);
930 settings->standby_time = BME280_GET_BITS(reg_data[3], BME280_STANDBY);
934 * @brief This internal API writes the power mode in the sensor.
936 static int8_t write_power_mode(uint8_t sensor_mode, const struct bme280_dev *dev)
939 uint8_t reg_addr = BME280_PWR_CTRL_ADDR;
941 /* Variable to store the value read from power mode register */
942 uint8_t sensor_mode_reg_val;
944 /* Read the power mode register */
945 rslt = bme280_get_regs(reg_addr, &sensor_mode_reg_val, 1, dev);
947 /* Set the power mode */
948 if (rslt == BME280_OK)
950 sensor_mode_reg_val = BME280_SET_BITS_POS_0(sensor_mode_reg_val, BME280_SENSOR_MODE, sensor_mode);
952 /* Write the power mode in the register */
953 rslt = bme280_set_regs(®_addr, &sensor_mode_reg_val, 1, dev);
960 * @brief This internal API puts the device to sleep mode.
962 static int8_t put_device_to_sleep(const struct bme280_dev *dev)
966 struct bme280_settings settings;
968 rslt = bme280_get_regs(BME280_CTRL_HUM_ADDR, reg_data, 4, dev);
969 if (rslt == BME280_OK)
971 parse_device_settings(reg_data, &settings);
972 rslt = bme280_soft_reset(dev);
973 if (rslt == BME280_OK)
975 rslt = reload_device_settings(&settings, dev);
983 * @brief This internal API reloads the already existing device settings in
984 * the sensor after soft reset.
986 static int8_t reload_device_settings(const struct bme280_settings *settings, const struct bme280_dev *dev)
990 rslt = set_osr_settings(BME280_ALL_SETTINGS_SEL, settings, dev);
991 if (rslt == BME280_OK)
993 rslt = set_filter_standby_settings(BME280_ALL_SETTINGS_SEL, settings, dev);
999 #ifdef BME280_FLOAT_ENABLE
1002 * @brief This internal API is used to compensate the raw temperature data and
1003 * return the compensated temperature data in double data type.
1005 static double compensate_temperature(const struct bme280_uncomp_data *uncomp_data, struct bme280_calib_data *calib_data)
1010 double temperature_min = -40;
1011 double temperature_max = 85;
1013 var1 = ((double)uncomp_data->temperature) / 16384.0 - ((double)calib_data->dig_T1) / 1024.0;
1014 var1 = var1 * ((double)calib_data->dig_T2);
1015 var2 = (((double)uncomp_data->temperature) / 131072.0 - ((double)calib_data->dig_T1) / 8192.0);
1016 var2 = (var2 * var2) * ((double)calib_data->dig_T3);
1017 calib_data->t_fine = (int32_t)(var1 + var2);
1018 temperature = (var1 + var2) / 5120.0;
1019 if (temperature < temperature_min)
1021 temperature = temperature_min;
1023 else if (temperature > temperature_max)
1025 temperature = temperature_max;
1032 * @brief This internal API is used to compensate the raw pressure data and
1033 * return the compensated pressure data in double data type.
1035 static double compensate_pressure(const struct bme280_uncomp_data *uncomp_data,
1036 const struct bme280_calib_data *calib_data)
1042 double pressure_min = 30000.0;
1043 double pressure_max = 110000.0;
1045 var1 = ((double)calib_data->t_fine / 2.0) - 64000.0;
1046 var2 = var1 * var1 * ((double)calib_data->dig_P6) / 32768.0;
1047 var2 = var2 + var1 * ((double)calib_data->dig_P5) * 2.0;
1048 var2 = (var2 / 4.0) + (((double)calib_data->dig_P4) * 65536.0);
1049 var3 = ((double)calib_data->dig_P3) * var1 * var1 / 524288.0;
1050 var1 = (var3 + ((double)calib_data->dig_P2) * var1) / 524288.0;
1051 var1 = (1.0 + var1 / 32768.0) * ((double)calib_data->dig_P1);
1053 /* avoid exception caused by division by zero */
1056 pressure = 1048576.0 - (double) uncomp_data->pressure;
1057 pressure = (pressure - (var2 / 4096.0)) * 6250.0 / var1;
1058 var1 = ((double)calib_data->dig_P9) * pressure * pressure / 2147483648.0;
1059 var2 = pressure * ((double)calib_data->dig_P8) / 32768.0;
1060 pressure = pressure + (var1 + var2 + ((double)calib_data->dig_P7)) / 16.0;
1061 if (pressure < pressure_min)
1063 pressure = pressure_min;
1065 else if (pressure > pressure_max)
1067 pressure = pressure_max;
1070 else /* Invalid case */
1072 pressure = pressure_min;
1079 * @brief This internal API is used to compensate the raw humidity data and
1080 * return the compensated humidity data in double data type.
1082 static double compensate_humidity(const struct bme280_uncomp_data *uncomp_data,
1083 const struct bme280_calib_data *calib_data)
1086 double humidity_min = 0.0;
1087 double humidity_max = 100.0;
1095 var1 = ((double)calib_data->t_fine) - 76800.0;
1096 var2 = (((double)calib_data->dig_H4) * 64.0 + (((double)calib_data->dig_H5) / 16384.0) * var1);
1097 var3 = uncomp_data->humidity - var2;
1098 var4 = ((double)calib_data->dig_H2) / 65536.0;
1099 var5 = (1.0 + (((double)calib_data->dig_H3) / 67108864.0) * var1);
1100 var6 = 1.0 + (((double)calib_data->dig_H6) / 67108864.0) * var1 * var5;
1101 var6 = var3 * var4 * (var5 * var6);
1102 humidity = var6 * (1.0 - ((double)calib_data->dig_H1) * var6 / 524288.0);
1103 if (humidity > humidity_max)
1105 humidity = humidity_max;
1107 else if (humidity < humidity_min)
1109 humidity = humidity_min;
1118 * @brief This internal API is used to compensate the raw temperature data and
1119 * return the compensated temperature data in integer data type.
1121 static int32_t compensate_temperature(const struct bme280_uncomp_data *uncomp_data,
1122 struct bme280_calib_data *calib_data)
1126 int32_t temperature;
1127 int32_t temperature_min = -4000;
1128 int32_t temperature_max = 8500;
1130 var1 = (int32_t)((uncomp_data->temperature / 8) - ((int32_t)calib_data->dig_T1 * 2));
1131 var1 = (var1 * ((int32_t)calib_data->dig_T2)) / 2048;
1132 var2 = (int32_t)((uncomp_data->temperature / 16) - ((int32_t)calib_data->dig_T1));
1133 var2 = (((var2 * var2) / 4096) * ((int32_t)calib_data->dig_T3)) / 16384;
1134 calib_data->t_fine = var1 + var2;
1135 temperature = (calib_data->t_fine * 5 + 128) / 256;
1136 if (temperature < temperature_min)
1138 temperature = temperature_min;
1140 else if (temperature > temperature_max)
1142 temperature = temperature_max;
1147 #ifdef BME280_64BIT_ENABLE
1150 * @brief This internal API is used to compensate the raw pressure data and
1151 * return the compensated pressure data in integer data type with higher
1154 static uint32_t compensate_pressure(const struct bme280_uncomp_data *uncomp_data,
1155 const struct bme280_calib_data *calib_data)
1162 uint32_t pressure_min = 3000000;
1163 uint32_t pressure_max = 11000000;
1165 var1 = ((int64_t)calib_data->t_fine) - 128000;
1166 var2 = var1 * var1 * (int64_t)calib_data->dig_P6;
1167 var2 = var2 + ((var1 * (int64_t)calib_data->dig_P5) * 131072);
1168 var2 = var2 + (((int64_t)calib_data->dig_P4) * 34359738368);
1169 var1 = ((var1 * var1 * (int64_t)calib_data->dig_P3) / 256) + ((var1 * ((int64_t)calib_data->dig_P2) * 4096));
1170 var3 = ((int64_t)1) * 140737488355328;
1171 var1 = (var3 + var1) * ((int64_t)calib_data->dig_P1) / 8589934592;
1173 /* To avoid divide by zero exception */
1176 var4 = 1048576 - uncomp_data->pressure;
1177 var4 = (((var4 * INT64_C(2147483648)) - var2) * 3125) / var1;
1178 var1 = (((int64_t)calib_data->dig_P9) * (var4 / 8192) * (var4 / 8192)) / 33554432;
1179 var2 = (((int64_t)calib_data->dig_P8) * var4) / 524288;
1180 var4 = ((var4 + var1 + var2) / 256) + (((int64_t)calib_data->dig_P7) * 16);
1181 pressure = (uint32_t)(((var4 / 2) * 100) / 128);
1182 if (pressure < pressure_min)
1184 pressure = pressure_min;
1186 else if (pressure > pressure_max)
1188 pressure = pressure_max;
1193 pressure = pressure_min;
1201 * @brief This internal API is used to compensate the raw pressure data and
1202 * return the compensated pressure data in integer data type.
1204 static uint32_t compensate_pressure(const struct bme280_uncomp_data *uncomp_data,
1205 const struct bme280_calib_data *calib_data)
1213 uint32_t pressure_min = 30000;
1214 uint32_t pressure_max = 110000;
1216 var1 = (((int32_t)calib_data->t_fine) / 2) - (int32_t)64000;
1217 var2 = (((var1 / 4) * (var1 / 4)) / 2048) * ((int32_t)calib_data->dig_P6);
1218 var2 = var2 + ((var1 * ((int32_t)calib_data->dig_P5)) * 2);
1219 var2 = (var2 / 4) + (((int32_t)calib_data->dig_P4) * 65536);
1220 var3 = (calib_data->dig_P3 * (((var1 / 4) * (var1 / 4)) / 8192)) / 8;
1221 var4 = (((int32_t)calib_data->dig_P2) * var1) / 2;
1222 var1 = (var3 + var4) / 262144;
1223 var1 = (((32768 + var1)) * ((int32_t)calib_data->dig_P1)) / 32768;
1225 /* avoid exception caused by division by zero */
1228 var5 = (uint32_t)((uint32_t)1048576) - uncomp_data->pressure;
1229 pressure = ((uint32_t)(var5 - (uint32_t)(var2 / 4096))) * 3125;
1230 if (pressure < 0x80000000)
1232 pressure = (pressure << 1) / ((uint32_t)var1);
1236 pressure = (pressure / (uint32_t)var1) * 2;
1238 var1 = (((int32_t)calib_data->dig_P9) * ((int32_t)(((pressure / 8) * (pressure / 8)) / 8192))) / 4096;
1239 var2 = (((int32_t)(pressure / 4)) * ((int32_t)calib_data->dig_P8)) / 8192;
1240 pressure = (uint32_t)((int32_t)pressure + ((var1 + var2 + calib_data->dig_P7) / 16));
1241 if (pressure < pressure_min)
1243 pressure = pressure_min;
1245 else if (pressure > pressure_max)
1247 pressure = pressure_max;
1252 pressure = pressure_min;
1260 * @brief This internal API is used to compensate the raw humidity data and
1261 * return the compensated humidity data in integer data type.
1263 static uint32_t compensate_humidity(const struct bme280_uncomp_data *uncomp_data,
1264 const struct bme280_calib_data *calib_data)
1272 uint32_t humidity_max = 102400;
1274 var1 = calib_data->t_fine - ((int32_t)76800);
1275 var2 = (int32_t)(uncomp_data->humidity * 16384);
1276 var3 = (int32_t)(((int32_t)calib_data->dig_H4) * 1048576);
1277 var4 = ((int32_t)calib_data->dig_H5) * var1;
1278 var5 = (((var2 - var3) - var4) + (int32_t)16384) / 32768;
1279 var2 = (var1 * ((int32_t)calib_data->dig_H6)) / 1024;
1280 var3 = (var1 * ((int32_t)calib_data->dig_H3)) / 2048;
1281 var4 = ((var2 * (var3 + (int32_t)32768)) / 1024) + (int32_t)2097152;
1282 var2 = ((var4 * ((int32_t)calib_data->dig_H2)) + 8192) / 16384;
1284 var4 = ((var3 / 32768) * (var3 / 32768)) / 128;
1285 var5 = var3 - ((var4 * ((int32_t)calib_data->dig_H1)) / 16);
1286 var5 = (var5 < 0 ? 0 : var5);
1287 var5 = (var5 > 419430400 ? 419430400 : var5);
1288 humidity = (uint32_t)(var5 / 4096);
1289 if (humidity > humidity_max)
1291 humidity = humidity_max;
1299 * @brief This internal API reads the calibration data from the sensor, parse
1300 * it and store in the device structure.
1302 static int8_t get_calib_data(struct bme280_dev *dev)
1305 uint8_t reg_addr = BME280_TEMP_PRESS_CALIB_DATA_ADDR;
1307 /* Array to store calibration data */
1308 uint8_t calib_data[BME280_TEMP_PRESS_CALIB_DATA_LEN] = { 0 };
1310 /* Read the calibration data from the sensor */
1311 rslt = bme280_get_regs(reg_addr, calib_data, BME280_TEMP_PRESS_CALIB_DATA_LEN, dev);
1312 if (rslt == BME280_OK)
1314 /* Parse temperature and pressure calibration data and store
1315 * it in device structure
1317 parse_temp_press_calib_data(calib_data, dev);
1318 reg_addr = BME280_HUMIDITY_CALIB_DATA_ADDR;
1320 /* Read the humidity calibration data from the sensor */
1321 rslt = bme280_get_regs(reg_addr, calib_data, BME280_HUMIDITY_CALIB_DATA_LEN, dev);
1322 if (rslt == BME280_OK)
1324 /* Parse humidity calibration data and store it in
1327 parse_humidity_calib_data(calib_data, dev);
1335 * @brief This internal API interleaves the register address between the
1336 * register data buffer for burst write operation.
1338 static void interleave_reg_addr(const uint8_t *reg_addr, uint8_t *temp_buff, const uint8_t *reg_data, uint8_t len)
1342 for (index = 1; index < len; index++)
1344 temp_buff[(index * 2) - 1] = reg_addr[index];
1345 temp_buff[index * 2] = reg_data[index];
1350 * @brief This internal API is used to parse the temperature and
1351 * pressure calibration data and store it in device structure.
1353 static void parse_temp_press_calib_data(const uint8_t *reg_data, struct bme280_dev *dev)
1355 struct bme280_calib_data *calib_data = &dev->calib_data;
1357 calib_data->dig_T1 = BME280_CONCAT_BYTES(reg_data[1], reg_data[0]);
1358 calib_data->dig_T2 = (int16_t)BME280_CONCAT_BYTES(reg_data[3], reg_data[2]);
1359 calib_data->dig_T3 = (int16_t)BME280_CONCAT_BYTES(reg_data[5], reg_data[4]);
1360 calib_data->dig_P1 = BME280_CONCAT_BYTES(reg_data[7], reg_data[6]);
1361 calib_data->dig_P2 = (int16_t)BME280_CONCAT_BYTES(reg_data[9], reg_data[8]);
1362 calib_data->dig_P3 = (int16_t)BME280_CONCAT_BYTES(reg_data[11], reg_data[10]);
1363 calib_data->dig_P4 = (int16_t)BME280_CONCAT_BYTES(reg_data[13], reg_data[12]);
1364 calib_data->dig_P5 = (int16_t)BME280_CONCAT_BYTES(reg_data[15], reg_data[14]);
1365 calib_data->dig_P6 = (int16_t)BME280_CONCAT_BYTES(reg_data[17], reg_data[16]);
1366 calib_data->dig_P7 = (int16_t)BME280_CONCAT_BYTES(reg_data[19], reg_data[18]);
1367 calib_data->dig_P8 = (int16_t)BME280_CONCAT_BYTES(reg_data[21], reg_data[20]);
1368 calib_data->dig_P9 = (int16_t)BME280_CONCAT_BYTES(reg_data[23], reg_data[22]);
1369 calib_data->dig_H1 = reg_data[25];
1373 * @brief This internal API is used to parse the humidity calibration data
1374 * and store it in device structure.
1376 static void parse_humidity_calib_data(const uint8_t *reg_data, struct bme280_dev *dev)
1378 struct bme280_calib_data *calib_data = &dev->calib_data;
1384 calib_data->dig_H2 = (int16_t)BME280_CONCAT_BYTES(reg_data[1], reg_data[0]);
1385 calib_data->dig_H3 = reg_data[2];
1386 dig_H4_msb = (int16_t)(int8_t)reg_data[3] * 16;
1387 dig_H4_lsb = (int16_t)(reg_data[4] & 0x0F);
1388 calib_data->dig_H4 = dig_H4_msb | dig_H4_lsb;
1389 dig_H5_msb = (int16_t)(int8_t)reg_data[5] * 16;
1390 dig_H5_lsb = (int16_t)(reg_data[4] >> 4);
1391 calib_data->dig_H5 = dig_H5_msb | dig_H5_lsb;
1392 calib_data->dig_H6 = (int8_t)reg_data[6];
1396 * @brief This internal API is used to identify the settings which the user
1397 * wants to modify in the sensor.
1399 static uint8_t are_settings_changed(uint8_t sub_settings, uint8_t desired_settings)
1401 uint8_t settings_changed = FALSE;
1403 if (sub_settings & desired_settings)
1405 /* User wants to modify this particular settings */
1406 settings_changed = TRUE;
1410 /* User don't want to modify this particular settings */
1411 settings_changed = FALSE;
1414 return settings_changed;
1418 * @brief This internal API is used to validate the device structure pointer for
1421 static int8_t null_ptr_check(const struct bme280_dev *dev)
1425 if ((dev == NULL) || (dev->read == NULL) || (dev->write == NULL) || (dev->delay_ms == NULL))
1427 /* Device structure pointer is not valid */
1428 rslt = BME280_E_NULL_PTR;
1432 /* Device structure is fine */