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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);
132 #ifdef BME280_FLOAT_ENABLE
134 * @brief This internal API is used to compensate the raw pressure data and
135 * return the compensated pressure data in double data type.
137 * @param[in] uncomp_data : Contains the uncompensated pressure data.
138 * @param[in] calib_data : Pointer to the calibration data structure.
140 * @return Compensated pressure data.
141 * @retval Compensated pressure data in double.
143 static double compensate_pressure(const struct bme280_uncomp_data *uncomp_data,
144 const struct bme280_calib_data *calib_data);
147 * @brief This internal API is used to compensate the raw humidity data and
148 * return the compensated humidity data in double data type.
150 * @param[in] uncomp_data : Contains the uncompensated humidity data.
151 * @param[in] calib_data : Pointer to the calibration data structure.
153 * @return Compensated humidity data.
154 * @retval Compensated humidity data in double.
156 static double compensate_humidity(const struct bme280_uncomp_data *uncomp_data,
157 const struct bme280_calib_data *calib_data);
160 * @brief This internal API is used to compensate the raw temperature data and
161 * return the compensated temperature data in double data type.
163 * @param[in] uncomp_data : Contains the uncompensated temperature data.
164 * @param[in] calib_data : Pointer to calibration data structure.
166 * @return Compensated temperature data.
167 * @retval Compensated temperature data in double.
169 static double compensate_temperature(const struct bme280_uncomp_data *uncomp_data,
170 struct bme280_calib_data *calib_data);
175 * @brief This internal API is used to compensate the raw temperature data and
176 * return the compensated temperature data in integer data type.
178 * @param[in] uncomp_data : Contains the uncompensated temperature data.
179 * @param[in] calib_data : Pointer to calibration data structure.
181 * @return Compensated temperature data.
182 * @retval Compensated temperature data in integer.
184 static int32_t compensate_temperature(const struct bme280_uncomp_data *uncomp_data,
185 struct bme280_calib_data *calib_data);
188 * @brief This internal API is used to compensate the raw pressure data and
189 * return the compensated pressure data in integer data type.
191 * @param[in] uncomp_data : Contains the uncompensated pressure data.
192 * @param[in] calib_data : Pointer to the calibration data structure.
194 * @return Compensated pressure data.
195 * @retval Compensated pressure data in integer.
197 static uint32_t compensate_pressure(const struct bme280_uncomp_data *uncomp_data,
198 const struct bme280_calib_data *calib_data);
201 * @brief This internal API is used to compensate the raw humidity data and
202 * return the compensated humidity data in integer data type.
204 * @param[in] uncomp_data : Contains the uncompensated humidity data.
205 * @param[in] calib_data : Pointer to the calibration data structure.
207 * @return Compensated humidity data.
208 * @retval Compensated humidity data in integer.
210 static uint32_t compensate_humidity(const struct bme280_uncomp_data *uncomp_data,
211 const struct bme280_calib_data *calib_data);
216 * @brief This internal API is used to identify the settings which the user
217 * wants to modify in the sensor.
219 * @param[in] sub_settings : Contains the settings subset to identify particular
220 * group of settings which the user is interested to change.
221 * @param[in] desired_settings : Contains the user specified settings.
223 * @return Indicates whether user is interested to modify the settings which
224 * are related to sub_settings.
225 * @retval True -> User wants to modify this group of settings
226 * @retval False -> User does not want to modify this group of settings
228 static uint8_t are_settings_changed(uint8_t sub_settings, uint8_t desired_settings);
231 * @brief This API sets the humidity oversampling settings of the sensor.
233 * @param[in] dev : Structure instance of bme280_dev.
235 * @return Result of API execution status
236 * @retval zero -> Success / +ve value -> Warning / -ve value -> Error
238 static int8_t set_osr_humidity_settings(const struct bme280_settings *settings, const struct bme280_dev *dev);
241 * @brief This internal API sets the oversampling settings for pressure,
242 * temperature and humidity in the sensor.
244 * @param[in] desired_settings : Variable used to select the settings which
246 * @param[in] dev : Structure instance of bme280_dev.
248 * @return Result of API execution status
249 * @retval zero -> Success / +ve value -> Warning / -ve value -> Error
251 static int8_t set_osr_settings(uint8_t desired_settings, const struct bme280_settings *settings,
252 const struct bme280_dev *dev);
255 * @brief This API sets the pressure and/or temperature oversampling settings
256 * in the sensor according to the settings selected by the user.
258 * @param[in] dev : Structure instance of bme280_dev.
259 * @param[in] desired_settings: variable to select the pressure and/or
260 * temperature oversampling settings.
262 * @return Result of API execution status
263 * @retval zero -> Success / +ve value -> Warning / -ve value -> Error
265 static int8_t set_osr_press_temp_settings(uint8_t desired_settings, const struct bme280_settings *settings,
266 const struct bme280_dev *dev);
269 * @brief This internal API fills the pressure oversampling settings provided by
270 * the user in the data buffer so as to write in the sensor.
272 * @param[in] dev : Structure instance of bme280_dev.
273 * @param[out] reg_data : Variable which is filled according to the pressure
274 * oversampling data provided by the user.
276 static void fill_osr_press_settings(uint8_t *reg_data, const struct bme280_settings *settings);
279 * @brief This internal API fills the temperature oversampling settings provided
280 * by the user in the data buffer so as to write in the sensor.
282 * @param[in] dev : Structure instance of bme280_dev.
283 * @param[out] reg_data : Variable which is filled according to the temperature
284 * oversampling data provided by the user.
286 static void fill_osr_temp_settings(uint8_t *reg_data, const struct bme280_settings *settings);
289 * @brief This internal API sets the filter and/or standby duration settings
290 * in the sensor according to the settings selected by the user.
292 * @param[in] dev : Structure instance of bme280_dev.
293 * @param[in] desired_settings : variable to select the filter and/or
294 * standby duration settings.
296 * @return Result of API execution status
297 * @retval zero -> Success / +ve value -> Warning / -ve value -> Error
299 static int8_t set_filter_standby_settings(uint8_t desired_settings, const struct bme280_settings *settings,
300 const struct bme280_dev *dev);
303 * @brief This internal API fills the filter settings provided by the user
304 * in the data buffer so as to write in the sensor.
306 * @param[in] dev : Structure instance of bme280_dev.
307 * @param[out] reg_data : Variable which is filled according to the filter
308 * settings data provided by the user.
310 static void fill_filter_settings(uint8_t *reg_data, const struct bme280_settings *settings);
313 * @brief This internal API fills the standby duration settings provided by the
314 * user in the data buffer so as to write in the sensor.
316 * @param[in] dev : Structure instance of bme280_dev.
317 * @param[out] reg_data : Variable which is filled according to the standby
318 * settings data provided by the user.
320 static void fill_standby_settings(uint8_t *reg_data, const struct bme280_settings *settings);
323 * @brief This internal API parse the oversampling(pressure, temperature
324 * and humidity), filter and standby duration settings and store in the
327 * @param[out] dev : Structure instance of bme280_dev.
328 * @param[in] reg_data : Register data to be parsed.
330 static void parse_device_settings(const uint8_t *reg_data, struct bme280_settings *settings);
333 * @brief This internal API reloads the already existing device settings in the
334 * sensor after soft reset.
336 * @param[in] dev : Structure instance of bme280_dev.
337 * @param[in] settings : Pointer variable which contains the settings to
338 * be set in the sensor.
340 * @return Result of API execution status
341 * @retval zero -> Success / +ve value -> Warning / -ve value -> Error
343 static int8_t reload_device_settings(const struct bme280_settings *settings, const struct bme280_dev *dev);
345 /****************** Global Function Definitions *******************************/
348 * @brief This API is the entry point.
349 * It reads the chip-id and calibration data from the sensor.
351 int8_t bme280_init(struct bme280_dev *dev)
354 /* chip id read try count */
355 uint8_t try_count = 5;
358 /* Check for null pointer in the device structure*/
359 rslt = null_ptr_check(dev);
360 /* Proceed if null check is fine */
361 if (rslt == BME280_OK) {
363 /* Read the chip-id of bme280 sensor */
364 rslt = bme280_get_regs(BME280_CHIP_ID_ADDR, &chip_id, 1, dev);
365 /* Check for chip id validity */
366 if ((rslt == BME280_OK) && (chip_id == BME280_CHIP_ID)) {
367 dev->chip_id = chip_id;
368 /* Reset the sensor */
369 rslt = bme280_soft_reset(dev);
370 if (rslt == BME280_OK) {
371 /* Read the calibration data */
372 rslt = get_calib_data(dev);
380 /* Chip id check failed */
382 rslt = BME280_E_DEV_NOT_FOUND;
389 * @brief This API reads the data from the given register address of the sensor.
391 int8_t bme280_get_regs(uint8_t reg_addr, uint8_t *reg_data, uint16_t len, const struct bme280_dev *dev)
395 /* Check for null pointer in the device structure*/
396 rslt = null_ptr_check(dev);
397 /* Proceed if null check is fine */
398 if (rslt == BME280_OK) {
399 /* If interface selected is SPI */
400 if (dev->intf != BME280_I2C_INTF)
401 reg_addr = reg_addr | 0x80;
403 rslt = dev->read(dev->dev_id, reg_addr, reg_data, len);
404 /* Check for communication error */
405 if (rslt != BME280_OK)
406 rslt = BME280_E_COMM_FAIL;
413 * @brief This API writes the given data to the register address
416 int8_t bme280_set_regs(uint8_t *reg_addr, const uint8_t *reg_data, uint8_t len, const struct bme280_dev *dev)
419 uint8_t temp_buff[20]; /* Typically not to write more than 10 registers */
425 uint8_t reg_addr_cnt;
427 /* Check for null pointer in the device structure*/
428 rslt = null_ptr_check(dev);
429 /* Check for arguments validity */
430 if ((rslt == BME280_OK) && (reg_addr != NULL) && (reg_data != NULL)) {
432 temp_buff[0] = reg_data[0];
433 /* If interface selected is SPI */
434 if (dev->intf != BME280_I2C_INTF) {
435 for (reg_addr_cnt = 0; reg_addr_cnt < len; reg_addr_cnt++)
436 reg_addr[reg_addr_cnt] = reg_addr[reg_addr_cnt] & 0x7F;
438 /* Burst write mode */
440 /* Interleave register address w.r.t data for
442 interleave_reg_addr(reg_addr, temp_buff, reg_data, len);
447 rslt = dev->write(dev->dev_id, reg_addr[0], temp_buff, temp_len);
448 /* Check for communication error */
449 if (rslt != BME280_OK)
450 rslt = BME280_E_COMM_FAIL;
452 rslt = BME280_E_INVALID_LEN;
455 rslt = BME280_E_NULL_PTR;
463 * @brief This API sets the oversampling, filter and standby duration
464 * (normal mode) settings in the sensor.
466 int8_t bme280_set_sensor_settings(uint8_t desired_settings, const struct bme280_dev *dev)
471 /* Check for null pointer in the device structure*/
472 rslt = null_ptr_check(dev);
473 /* Proceed if null check is fine */
474 if (rslt == BME280_OK) {
475 rslt = bme280_get_sensor_mode(&sensor_mode, dev);
476 if ((rslt == BME280_OK) && (sensor_mode != BME280_SLEEP_MODE))
477 rslt = put_device_to_sleep(dev);
478 if (rslt == BME280_OK) {
479 /* Check if user wants to change oversampling
481 if (are_settings_changed(OVERSAMPLING_SETTINGS, desired_settings))
482 rslt = set_osr_settings(desired_settings, &dev->settings, dev);
483 /* Check if user wants to change filter and/or
485 if ((rslt == BME280_OK) && are_settings_changed(FILTER_STANDBY_SETTINGS, desired_settings))
486 rslt = set_filter_standby_settings(desired_settings, &dev->settings, dev);
494 * @brief This API gets the oversampling, filter and standby duration
495 * (normal mode) settings from the sensor.
497 int8_t bme280_get_sensor_settings(struct bme280_dev *dev)
502 /* Check for null pointer in the device structure*/
503 rslt = null_ptr_check(dev);
504 /* Proceed if null check is fine */
505 if (rslt == BME280_OK) {
506 rslt = bme280_get_regs(BME280_CTRL_HUM_ADDR, reg_data, 4, dev);
507 if (rslt == BME280_OK)
508 parse_device_settings(reg_data, &dev->settings);
515 * @brief This API sets the power mode of the sensor.
517 int8_t bme280_set_sensor_mode(uint8_t sensor_mode, const struct bme280_dev *dev)
520 uint8_t last_set_mode;
522 /* Check for null pointer in the device structure*/
523 rslt = null_ptr_check(dev);
525 if (rslt == BME280_OK) {
526 rslt = bme280_get_sensor_mode(&last_set_mode, dev);
527 /* If the sensor is not in sleep mode put the device to sleep
529 if ((rslt == BME280_OK) && (last_set_mode != BME280_SLEEP_MODE))
530 rslt = put_device_to_sleep(dev);
531 /* Set the power mode */
532 if (rslt == BME280_OK)
533 rslt = write_power_mode(sensor_mode, dev);
540 * @brief This API gets the power mode of the sensor.
542 int8_t bme280_get_sensor_mode(uint8_t *sensor_mode, const struct bme280_dev *dev)
546 /* Check for null pointer in the device structure*/
547 rslt = null_ptr_check(dev);
549 if (rslt == BME280_OK) {
550 /* Read the power mode register */
551 rslt = bme280_get_regs(BME280_PWR_CTRL_ADDR, sensor_mode, 1, dev);
552 /* Assign the power mode in the device structure */
553 *sensor_mode = BME280_GET_BITS_POS_0(*sensor_mode, BME280_SENSOR_MODE);
560 * @brief This API performs the soft reset of the sensor.
562 int8_t bme280_soft_reset(const struct bme280_dev *dev)
565 uint8_t reg_addr = BME280_RESET_ADDR;
566 /* 0xB6 is the soft reset command */
567 uint8_t soft_rst_cmd = 0xB6;
569 /* Check for null pointer in the device structure*/
570 rslt = null_ptr_check(dev);
571 /* Proceed if null check is fine */
572 if (rslt == BME280_OK) {
573 /* Write the soft reset command in the sensor */
574 rslt = bme280_set_regs(®_addr, &soft_rst_cmd, 1, dev);
575 /* As per data sheet, startup time is 2 ms. */
583 * @brief This API reads the pressure, temperature and humidity data from the
584 * sensor, compensates the data and store it in the bme280_data structure
585 * instance passed by the user.
587 int8_t bme280_get_sensor_data(uint8_t sensor_comp, struct bme280_data *comp_data, struct bme280_dev *dev)
590 /* Array to store the pressure, temperature and humidity data read from
592 uint8_t reg_data[BME280_P_T_H_DATA_LEN] = {0};
593 struct bme280_uncomp_data uncomp_data = {0};
595 /* Check for null pointer in the device structure*/
596 rslt = null_ptr_check(dev);
598 if ((rslt == BME280_OK) && (comp_data != NULL)) {
599 /* Read the pressure and temperature data from the sensor */
600 rslt = bme280_get_regs(BME280_DATA_ADDR, reg_data, BME280_P_T_H_DATA_LEN, dev);
602 if (rslt == BME280_OK) {
603 /* Parse the read data from the sensor */
604 bme280_parse_sensor_data(reg_data, &uncomp_data);
605 /* Compensate the pressure and/or temperature and/or
606 humidity data from the sensor */
607 rslt = bme280_compensate_data(sensor_comp, &uncomp_data, comp_data, &dev->calib_data);
610 rslt = BME280_E_NULL_PTR;
617 * @brief This API is used to parse the pressure, temperature and
618 * humidity data and store it in the bme280_uncomp_data structure instance.
620 void bme280_parse_sensor_data(const uint8_t *reg_data, struct bme280_uncomp_data *uncomp_data)
622 /* Variables to store the sensor data */
627 /* Store the parsed register values for pressure data */
628 data_msb = (uint32_t)reg_data[0] << 12;
629 data_lsb = (uint32_t)reg_data[1] << 4;
630 data_xlsb = (uint32_t)reg_data[2] >> 4;
631 uncomp_data->pressure = data_msb | data_lsb | data_xlsb;
633 /* Store the parsed register values for temperature data */
634 data_msb = (uint32_t)reg_data[3] << 12;
635 data_lsb = (uint32_t)reg_data[4] << 4;
636 data_xlsb = (uint32_t)reg_data[5] >> 4;
637 uncomp_data->temperature = data_msb | data_lsb | data_xlsb;
639 /* Store the parsed register values for temperature data */
640 data_lsb = (uint32_t)reg_data[6] << 8;
641 data_msb = (uint32_t)reg_data[7];
642 uncomp_data->humidity = data_msb | data_lsb;
647 * @brief This API is used to compensate the pressure and/or
648 * temperature and/or humidity data according to the component selected
651 int8_t bme280_compensate_data(uint8_t sensor_comp, const struct bme280_uncomp_data *uncomp_data,
652 struct bme280_data *comp_data, struct bme280_calib_data *calib_data)
654 int8_t rslt = BME280_OK;
656 if ((uncomp_data != NULL) && (comp_data != NULL) && (calib_data != NULL)) {
657 /* Initialize to zero */
658 comp_data->temperature = 0;
659 comp_data->pressure = 0;
660 comp_data->humidity = 0;
661 /* If pressure or temperature component is selected */
662 if (sensor_comp & (BME280_PRESS | BME280_TEMP | BME280_HUM)) {
663 /* Compensate the temperature data */
664 comp_data->temperature = compensate_temperature(uncomp_data, calib_data);
666 if (sensor_comp & BME280_PRESS) {
667 /* Compensate the pressure data */
668 comp_data->pressure = compensate_pressure(uncomp_data, calib_data);
670 if (sensor_comp & BME280_HUM) {
671 /* Compensate the humidity data */
672 comp_data->humidity = compensate_humidity(uncomp_data, calib_data);
675 rslt = BME280_E_NULL_PTR;
682 * @brief This internal API sets the oversampling settings for pressure,
683 * temperature and humidity in the sensor.
685 static int8_t set_osr_settings(uint8_t desired_settings, const struct bme280_settings *settings,
686 const struct bme280_dev *dev)
688 int8_t rslt = BME280_W_INVALID_OSR_MACRO;
690 if (desired_settings & BME280_OSR_HUM_SEL)
691 rslt = set_osr_humidity_settings(settings, dev);
692 if (desired_settings & (BME280_OSR_PRESS_SEL | BME280_OSR_TEMP_SEL))
693 rslt = set_osr_press_temp_settings(desired_settings, settings, dev);
699 * @brief This API sets the humidity oversampling settings of the sensor.
701 static int8_t set_osr_humidity_settings(const struct bme280_settings *settings, const struct bme280_dev *dev)
706 uint8_t reg_addr = BME280_CTRL_HUM_ADDR;
708 ctrl_hum = settings->osr_h & BME280_CTRL_HUM_MSK;
709 /* Write the humidity control value in the register */
710 rslt = bme280_set_regs(®_addr, &ctrl_hum, 1, dev);
711 /* Humidity related changes will be only effective after a
712 write operation to ctrl_meas register */
713 if (rslt == BME280_OK) {
714 reg_addr = BME280_CTRL_MEAS_ADDR;
715 rslt = bme280_get_regs(reg_addr, &ctrl_meas, 1, dev);
716 if (rslt == BME280_OK)
717 rslt = bme280_set_regs(®_addr, &ctrl_meas, 1, dev);
724 * @brief This API sets the pressure and/or temperature oversampling settings
725 * in the sensor according to the settings selected by the user.
727 static int8_t set_osr_press_temp_settings(uint8_t desired_settings, const struct bme280_settings *settings,
728 const struct bme280_dev *dev)
731 uint8_t reg_addr = BME280_CTRL_MEAS_ADDR;
734 rslt = bme280_get_regs(reg_addr, ®_data, 1, dev);
736 if (rslt == BME280_OK) {
737 if (desired_settings & BME280_OSR_PRESS_SEL)
738 fill_osr_press_settings(®_data, settings);
739 if (desired_settings & BME280_OSR_TEMP_SEL)
740 fill_osr_temp_settings(®_data, settings);
741 /* Write the oversampling settings in the register */
742 rslt = bme280_set_regs(®_addr, ®_data, 1, dev);
749 * @brief This internal API sets the filter and/or standby duration settings
750 * in the sensor according to the settings selected by the user.
752 static int8_t set_filter_standby_settings(uint8_t desired_settings, const struct bme280_settings *settings,
753 const struct bme280_dev *dev)
756 uint8_t reg_addr = BME280_CONFIG_ADDR;
759 rslt = bme280_get_regs(reg_addr, ®_data, 1, dev);
761 if (rslt == BME280_OK) {
762 if (desired_settings & BME280_FILTER_SEL)
763 fill_filter_settings(®_data, settings);
764 if (desired_settings & BME280_STANDBY_SEL)
765 fill_standby_settings(®_data, settings);
766 /* Write the oversampling settings in the register */
767 rslt = bme280_set_regs(®_addr, ®_data, 1, dev);
774 * @brief This internal API fills the filter settings provided by the user
775 * in the data buffer so as to write in the sensor.
777 static void fill_filter_settings(uint8_t *reg_data, const struct bme280_settings *settings)
779 *reg_data = BME280_SET_BITS(*reg_data, BME280_FILTER, settings->filter);
783 * @brief This internal API fills the standby duration settings provided by
784 * the user in the data buffer so as to write in the sensor.
786 static void fill_standby_settings(uint8_t *reg_data, const struct bme280_settings *settings)
788 *reg_data = BME280_SET_BITS(*reg_data, BME280_STANDBY, settings->standby_time);
792 * @brief This internal API fills the pressure oversampling settings provided by
793 * the user in the data buffer so as to write in the sensor.
795 static void fill_osr_press_settings(uint8_t *reg_data, const struct bme280_settings *settings)
797 *reg_data = BME280_SET_BITS(*reg_data, BME280_CTRL_PRESS, settings->osr_p);
801 * @brief This internal API fills the temperature oversampling settings
802 * provided by the user in the data buffer so as to write in the sensor.
804 static void fill_osr_temp_settings(uint8_t *reg_data, const struct bme280_settings *settings)
806 *reg_data = BME280_SET_BITS(*reg_data, BME280_CTRL_TEMP, settings->osr_t);
810 * @brief This internal API parse the oversampling(pressure, temperature
811 * and humidity), filter and standby duration settings and store in the
814 static void parse_device_settings(const uint8_t *reg_data, struct bme280_settings *settings)
816 settings->osr_h = BME280_GET_BITS_POS_0(reg_data[0], BME280_CTRL_HUM);
817 settings->osr_p = BME280_GET_BITS(reg_data[2], BME280_CTRL_PRESS);
818 settings->osr_t = BME280_GET_BITS(reg_data[2], BME280_CTRL_TEMP);
819 settings->filter = BME280_GET_BITS(reg_data[3], BME280_FILTER);
820 settings->standby_time = BME280_GET_BITS(reg_data[3], BME280_STANDBY);
823 * @brief This internal API writes the power mode in the sensor.
825 static int8_t write_power_mode(uint8_t sensor_mode, const struct bme280_dev *dev)
828 uint8_t reg_addr = BME280_PWR_CTRL_ADDR;
829 /* Variable to store the value read from power mode register */
830 uint8_t sensor_mode_reg_val;
832 /* Read the power mode register */
833 rslt = bme280_get_regs(reg_addr, &sensor_mode_reg_val, 1, dev);
834 /* Set the power mode */
835 if (rslt == BME280_OK) {
836 sensor_mode_reg_val = BME280_SET_BITS_POS_0(sensor_mode_reg_val, BME280_SENSOR_MODE, sensor_mode);
837 /* Write the power mode in the register */
838 rslt = bme280_set_regs(®_addr, &sensor_mode_reg_val, 1, dev);
845 * @brief This internal API puts the device to sleep mode.
847 static int8_t put_device_to_sleep(const struct bme280_dev *dev)
851 struct bme280_settings settings;
853 rslt = bme280_get_regs(BME280_CTRL_HUM_ADDR, reg_data, 4, dev);
854 if (rslt == BME280_OK) {
855 parse_device_settings(reg_data, &settings);
856 rslt = bme280_soft_reset(dev);
857 if (rslt == BME280_OK)
858 rslt = reload_device_settings(&settings, dev);
865 * @brief This internal API reloads the already existing device settings in
866 * the sensor after soft reset.
868 static int8_t reload_device_settings(const struct bme280_settings *settings, const struct bme280_dev *dev)
872 rslt = set_osr_settings(BME280_ALL_SETTINGS_SEL, settings, dev);
873 if (rslt == BME280_OK)
874 rslt = set_filter_standby_settings(BME280_ALL_SETTINGS_SEL, settings, dev);
879 #ifdef BME280_FLOAT_ENABLE
881 * @brief This internal API is used to compensate the raw temperature data and
882 * return the compensated temperature data in double data type.
884 static double compensate_temperature(const struct bme280_uncomp_data *uncomp_data,
885 struct bme280_calib_data *calib_data)
890 double temperature_min = -40;
891 double temperature_max = 85;
893 var1 = ((double)uncomp_data->temperature) / 16384.0 - ((double)calib_data->dig_T1) / 1024.0;
894 var1 = var1 * ((double)calib_data->dig_T2);
895 var2 = (((double)uncomp_data->temperature) / 131072.0 - ((double)calib_data->dig_T1) / 8192.0);
896 var2 = (var2 * var2) * ((double)calib_data->dig_T3);
897 calib_data->t_fine = (int32_t)(var1 + var2);
898 temperature = (var1 + var2) / 5120.0;
900 if (temperature < temperature_min)
901 temperature = temperature_min;
902 else if (temperature > temperature_max)
903 temperature = temperature_max;
909 * @brief This internal API is used to compensate the raw pressure data and
910 * return the compensated pressure data in double data type.
912 static double compensate_pressure(const struct bme280_uncomp_data *uncomp_data,
913 const struct bme280_calib_data *calib_data)
919 double pressure_min = 30000.0;
920 double pressure_max = 110000.0;
922 var1 = ((double)calib_data->t_fine / 2.0) - 64000.0;
923 var2 = var1 * var1 * ((double)calib_data->dig_P6) / 32768.0;
924 var2 = var2 + var1 * ((double)calib_data->dig_P5) * 2.0;
925 var2 = (var2 / 4.0) + (((double)calib_data->dig_P4) * 65536.0);
926 var3 = ((double)calib_data->dig_P3) * var1 * var1 / 524288.0;
927 var1 = (var3 + ((double)calib_data->dig_P2) * var1) / 524288.0;
928 var1 = (1.0 + var1 / 32768.0) * ((double)calib_data->dig_P1);
929 /* avoid exception caused by division by zero */
931 pressure = 1048576.0 - (double) uncomp_data->pressure;
932 pressure = (pressure - (var2 / 4096.0)) * 6250.0 / var1;
933 var1 = ((double)calib_data->dig_P9) * pressure * pressure / 2147483648.0;
934 var2 = pressure * ((double)calib_data->dig_P8) / 32768.0;
935 pressure = pressure + (var1 + var2 + ((double)calib_data->dig_P7)) / 16.0;
937 if (pressure < pressure_min)
938 pressure = pressure_min;
939 else if (pressure > pressure_max)
940 pressure = pressure_max;
941 } else { /* Invalid case */
942 pressure = pressure_min;
949 * @brief This internal API is used to compensate the raw humidity data and
950 * return the compensated humidity data in double data type.
952 static double compensate_humidity(const struct bme280_uncomp_data *uncomp_data,
953 const struct bme280_calib_data *calib_data)
956 double humidity_min = 0.0;
957 double humidity_max = 100.0;
965 var1 = ((double)calib_data->t_fine) - 76800.0;
966 var2 = (((double)calib_data->dig_H4) * 64.0 + (((double)calib_data->dig_H5) / 16384.0) * var1);
967 var3 = uncomp_data->humidity - var2;
968 var4 = ((double)calib_data->dig_H2) / 65536.0;
969 var5 = (1.0 + (((double)calib_data->dig_H3) / 67108864.0) * var1);
970 var6 = 1.0 + (((double)calib_data->dig_H6) / 67108864.0) * var1 * var5;
971 var6 = var3 * var4 * (var5 * var6);
972 humidity = var6 * (1.0 - ((double)calib_data->dig_H1) * var6 / 524288.0);
974 if (humidity > humidity_max)
975 humidity = humidity_max;
976 else if (humidity < humidity_min)
977 humidity = humidity_min;
984 * @brief This internal API is used to compensate the raw temperature data and
985 * return the compensated temperature data in integer data type.
987 static int32_t compensate_temperature(const struct bme280_uncomp_data *uncomp_data,
988 struct bme280_calib_data *calib_data)
993 int32_t temperature_min = -4000;
994 int32_t temperature_max = 8500;
996 var1 = (int32_t)((uncomp_data->temperature / 8) - ((int32_t)calib_data->dig_T1 * 2));
997 var1 = (var1 * ((int32_t)calib_data->dig_T2)) / 2048;
998 var2 = (int32_t)((uncomp_data->temperature / 16) - ((int32_t)calib_data->dig_T1));
999 var2 = (((var2 * var2) / 4096) * ((int32_t)calib_data->dig_T3)) / 16384;
1000 calib_data->t_fine = var1 + var2;
1001 temperature = (calib_data->t_fine * 5 + 128) / 256;
1003 if (temperature < temperature_min)
1004 temperature = temperature_min;
1005 else if (temperature > temperature_max)
1006 temperature = temperature_max;
1010 #ifdef BME280_64BIT_ENABLE
1012 * @brief This internal API is used to compensate the raw pressure data and
1013 * return the compensated pressure data in integer data type with higher
1016 static uint32_t compensate_pressure(const struct bme280_uncomp_data *uncomp_data,
1017 const struct bme280_calib_data *calib_data)
1024 uint32_t pressure_min = 3000000;
1025 uint32_t pressure_max = 11000000;
1027 var1 = ((int64_t)calib_data->t_fine) - 128000;
1028 var2 = var1 * var1 * (int64_t)calib_data->dig_P6;
1029 var2 = var2 + ((var1 * (int64_t)calib_data->dig_P5) * 131072);
1030 var2 = var2 + (((int64_t)calib_data->dig_P4) * 34359738368);
1031 var1 = ((var1 * var1 * (int64_t)calib_data->dig_P3) / 256) + ((var1 * ((int64_t)calib_data->dig_P2) * 4096));
1032 var3 = ((int64_t)1) * 140737488355328;
1033 var1 = (var3 + var1) * ((int64_t)calib_data->dig_P1) / 8589934592;
1035 /* To avoid divide by zero exception */
1037 var4 = 1048576 - uncomp_data->pressure;
1038 var4 = (((var4 * 2147483648) - var2) * 3125) / var1;
1039 var1 = (((int64_t)calib_data->dig_P9) * (var4 / 8192) * (var4 / 8192)) / 33554432;
1040 var2 = (((int64_t)calib_data->dig_P8) * var4) / 524288;
1041 var4 = ((var4 + var1 + var2) / 256) + (((int64_t)calib_data->dig_P7) * 16);
1042 pressure = (uint32_t)(((var4 / 2) * 100) / 128);
1044 if (pressure < pressure_min)
1045 pressure = pressure_min;
1046 else if (pressure > pressure_max)
1047 pressure = pressure_max;
1049 pressure = pressure_min;
1056 * @brief This internal API is used to compensate the raw pressure data and
1057 * return the compensated pressure data in integer data type.
1059 static uint32_t compensate_pressure(const struct bme280_uncomp_data *uncomp_data,
1060 const struct bme280_calib_data *calib_data)
1068 uint32_t pressure_min = 30000;
1069 uint32_t pressure_max = 110000;
1071 var1 = (((int32_t)calib_data->t_fine) / 2) - (int32_t)64000;
1072 var2 = (((var1 / 4) * (var1 / 4)) / 2048) * ((int32_t)calib_data->dig_P6);
1073 var2 = var2 + ((var1 * ((int32_t)calib_data->dig_P5)) * 2);
1074 var2 = (var2 / 4) + (((int32_t)calib_data->dig_P4) * 65536);
1075 var3 = (calib_data->dig_P3 * (((var1 / 4) * (var1 / 4)) / 8192)) / 8;
1076 var4 = (((int32_t)calib_data->dig_P2) * var1) / 2;
1077 var1 = (var3 + var4) / 262144;
1078 var1 = (((32768 + var1)) * ((int32_t)calib_data->dig_P1)) / 32768;
1079 /* avoid exception caused by division by zero */
1081 var5 = (uint32_t)((uint32_t)1048576) - uncomp_data->pressure;
1082 pressure = ((uint32_t)(var5 - (uint32_t)(var2 / 4096))) * 3125;
1083 if (pressure < 0x80000000)
1084 pressure = (pressure << 1) / ((uint32_t)var1);
1086 pressure = (pressure / (uint32_t)var1) * 2;
1088 var1 = (((int32_t)calib_data->dig_P9) * ((int32_t)(((pressure / 8) * (pressure / 8)) / 8192))) / 4096;
1089 var2 = (((int32_t)(pressure / 4)) * ((int32_t)calib_data->dig_P8)) / 8192;
1090 pressure = (uint32_t)((int32_t)pressure + ((var1 + var2 + calib_data->dig_P7) / 16));
1092 if (pressure < pressure_min)
1093 pressure = pressure_min;
1094 else if (pressure > pressure_max)
1095 pressure = pressure_max;
1097 pressure = pressure_min;
1105 * @brief This internal API is used to compensate the raw humidity data and
1106 * return the compensated humidity data in integer data type.
1108 static uint32_t compensate_humidity(const struct bme280_uncomp_data *uncomp_data,
1109 const struct bme280_calib_data *calib_data)
1117 uint32_t humidity_max = 100000;
1119 var1 = calib_data->t_fine - ((int32_t)76800);
1120 var2 = (int32_t)(uncomp_data->humidity * 16384);
1121 var3 = (int32_t)(((int32_t)calib_data->dig_H4) * 1048576);
1122 var4 = ((int32_t)calib_data->dig_H5) * var1;
1123 var5 = (((var2 - var3) - var4) + (int32_t)16384) / 32768;
1124 var2 = (var1 * ((int32_t)calib_data->dig_H6)) / 1024;
1125 var3 = (var1 * ((int32_t)calib_data->dig_H3)) / 2048;
1126 var4 = ((var2 * (var3 + (int32_t)32768)) / 1024) + (int32_t)2097152;
1127 var2 = ((var4 * ((int32_t)calib_data->dig_H2)) + 8192) / 16384;
1129 var4 = ((var3 / 32768) * (var3 / 32768)) / 128;
1130 var5 = var3 - ((var4 * ((int32_t)calib_data->dig_H1)) / 16);
1131 var5 = (var5 < 0 ? 0 : var5);
1132 var5 = (var5 > 419430400 ? 419430400 : var5);
1133 humidity = (uint32_t)(var5 / 4096);
1135 if (humidity > humidity_max)
1136 humidity = humidity_max;
1143 * @brief This internal API reads the calibration data from the sensor, parse
1144 * it and store in the device structure.
1146 static int8_t get_calib_data(struct bme280_dev *dev)
1149 uint8_t reg_addr = BME280_TEMP_PRESS_CALIB_DATA_ADDR;
1150 /* Array to store calibration data */
1151 uint8_t calib_data[BME280_TEMP_PRESS_CALIB_DATA_LEN] = {0};
1153 /* Read the calibration data from the sensor */
1154 rslt = bme280_get_regs(reg_addr, calib_data, BME280_TEMP_PRESS_CALIB_DATA_LEN, dev);
1156 if (rslt == BME280_OK) {
1157 /* Parse temperature and pressure calibration data and store
1158 it in device structure */
1159 parse_temp_press_calib_data(calib_data, dev);
1161 reg_addr = BME280_HUMIDITY_CALIB_DATA_ADDR;
1162 /* Read the humidity calibration data from the sensor */
1163 rslt = bme280_get_regs(reg_addr, calib_data, BME280_HUMIDITY_CALIB_DATA_LEN, dev);
1164 if (rslt == BME280_OK) {
1165 /* Parse humidity calibration data and store it in
1167 parse_humidity_calib_data(calib_data, dev);
1175 * @brief This internal API interleaves the register address between the
1176 * register data buffer for burst write operation.
1178 static void interleave_reg_addr(const uint8_t *reg_addr, uint8_t *temp_buff, const uint8_t *reg_data, uint8_t len)
1182 for (index = 1; index < len; index++) {
1183 temp_buff[(index * 2) - 1] = reg_addr[index];
1184 temp_buff[index * 2] = reg_data[index];
1189 * @brief This internal API is used to parse the temperature and
1190 * pressure calibration data and store it in device structure.
1192 static void parse_temp_press_calib_data(const uint8_t *reg_data, struct bme280_dev *dev)
1194 struct bme280_calib_data *calib_data = &dev->calib_data;
1196 calib_data->dig_T1 = BME280_CONCAT_BYTES(reg_data[1], reg_data[0]);
1197 calib_data->dig_T2 = (int16_t)BME280_CONCAT_BYTES(reg_data[3], reg_data[2]);
1198 calib_data->dig_T3 = (int16_t)BME280_CONCAT_BYTES(reg_data[5], reg_data[4]);
1199 calib_data->dig_P1 = BME280_CONCAT_BYTES(reg_data[7], reg_data[6]);
1200 calib_data->dig_P2 = (int16_t)BME280_CONCAT_BYTES(reg_data[9], reg_data[8]);
1201 calib_data->dig_P3 = (int16_t)BME280_CONCAT_BYTES(reg_data[11], reg_data[10]);
1202 calib_data->dig_P4 = (int16_t)BME280_CONCAT_BYTES(reg_data[13], reg_data[12]);
1203 calib_data->dig_P5 = (int16_t)BME280_CONCAT_BYTES(reg_data[15], reg_data[14]);
1204 calib_data->dig_P6 = (int16_t)BME280_CONCAT_BYTES(reg_data[17], reg_data[16]);
1205 calib_data->dig_P7 = (int16_t)BME280_CONCAT_BYTES(reg_data[19], reg_data[18]);
1206 calib_data->dig_P8 = (int16_t)BME280_CONCAT_BYTES(reg_data[21], reg_data[20]);
1207 calib_data->dig_P9 = (int16_t)BME280_CONCAT_BYTES(reg_data[23], reg_data[22]);
1208 calib_data->dig_H1 = reg_data[25];
1213 * @brief This internal API is used to parse the humidity calibration data
1214 * and store it in device structure.
1216 static void parse_humidity_calib_data(const uint8_t *reg_data, struct bme280_dev *dev)
1218 struct bme280_calib_data *calib_data = &dev->calib_data;
1224 calib_data->dig_H2 = (int16_t)BME280_CONCAT_BYTES(reg_data[1], reg_data[0]);
1225 calib_data->dig_H3 = reg_data[2];
1227 dig_H4_msb = (int16_t)(int8_t)reg_data[3] * 16;
1228 dig_H4_lsb = (int16_t)(reg_data[4] & 0x0F);
1229 calib_data->dig_H4 = dig_H4_msb | dig_H4_lsb;
1231 dig_H5_msb = (int16_t)(int8_t)reg_data[5] * 16;
1232 dig_H5_lsb = (int16_t)(reg_data[4] >> 4);
1233 calib_data->dig_H5 = dig_H5_msb | dig_H5_lsb;
1234 calib_data->dig_H6 = (int8_t)reg_data[6];
1238 * @brief This internal API is used to identify the settings which the user
1239 * wants to modify in the sensor.
1241 static uint8_t are_settings_changed(uint8_t sub_settings, uint8_t desired_settings)
1243 uint8_t settings_changed = FALSE;
1245 if (sub_settings & desired_settings) {
1246 /* User wants to modify this particular settings */
1247 settings_changed = TRUE;
1249 /* User don't want to modify this particular settings */
1250 settings_changed = FALSE;
1253 return settings_changed;
1257 * @brief This internal API is used to validate the device structure pointer for
1260 static int8_t null_ptr_check(const struct bme280_dev *dev)
1264 if ((dev == NULL) || (dev->read == NULL) || (dev->write == NULL) || (dev->delay_ms == NULL)) {
1265 /* Device structure pointer is not valid */
1266 rslt = BME280_E_NULL_PTR;
1268 /* Device structure is fine */