/** * Copyright (c) 2020 Bosch Sensortec GmbH. All rights reserved. * * BSD-3-Clause * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * 3. Neither the name of the copyright holder nor the names of its * contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * * @file bme280.c * @date 2020-01-24 * @version v3.4.3 * */ /*! @file bme280.c * @brief Sensor driver for BME280 sensor */ #include "bme280.h" /**\name Internal macros */ /* To identify osr settings selected by user */ #define OVERSAMPLING_SETTINGS UINT8_C(0x07) /* To identify filter and standby settings selected by user */ #define FILTER_STANDBY_SETTINGS UINT8_C(0x18) /*! * @brief This internal API puts the device to sleep mode. * * @param[in] dev : Structure instance of bme280_dev. * * @return Result of API execution status. * @retval zero -> Success / +ve value -> Warning / -ve value -> Error */ static int8_t put_device_to_sleep(const struct bme280_dev *dev); /*! * @brief This internal API writes the power mode in the sensor. * * @param[in] dev : Structure instance of bme280_dev. * @param[in] sensor_mode : Variable which contains the power mode to be set. * * @return Result of API execution status. * @retval zero -> Success / +ve value -> Warning / -ve value -> Error */ static int8_t write_power_mode(uint8_t sensor_mode, const struct bme280_dev *dev); /*! * @brief This internal API is used to validate the device pointer for * null conditions. * * @param[in] dev : Structure instance of bme280_dev. * * @return Result of API execution status * @retval zero -> Success / +ve value -> Warning / -ve value -> Error */ static int8_t null_ptr_check(const struct bme280_dev *dev); /*! * @brief This internal API interleaves the register address between the * register data buffer for burst write operation. * * @param[in] reg_addr : Contains the register address array. * @param[out] temp_buff : Contains the temporary buffer to store the * register data and register address. * @param[in] reg_data : Contains the register data to be written in the * temporary buffer. * @param[in] len : No of bytes of data to be written for burst write. */ static void interleave_reg_addr(const uint8_t *reg_addr, uint8_t *temp_buff, const uint8_t *reg_data, uint8_t len); /*! * @brief This internal API reads the calibration data from the sensor, parse * it and store in the device structure. * * @param[in] dev : Structure instance of bme280_dev. * * @return Result of API execution status * @retval zero -> Success / +ve value -> Warning / -ve value -> Error */ static int8_t get_calib_data(struct bme280_dev *dev); /*! * @brief This internal API is used to parse the temperature and * pressure calibration data and store it in the device structure. * * @param[out] dev : Structure instance of bme280_dev to store the calib data. * @param[in] reg_data : Contains the calibration data to be parsed. */ static void parse_temp_press_calib_data(const uint8_t *reg_data, struct bme280_dev *dev); /*! * @brief This internal API is used to parse the humidity calibration data * and store it in device structure. * * @param[out] dev : Structure instance of bme280_dev to store the calib data. * @param[in] reg_data : Contains calibration data to be parsed. */ static void parse_humidity_calib_data(const uint8_t *reg_data, struct bme280_dev *dev); #ifdef BME280_FLOAT_ENABLE /*! * @brief This internal API is used to compensate the raw pressure data and * return the compensated pressure data in double data type. * * @param[in] uncomp_data : Contains the uncompensated pressure data. * @param[in] calib_data : Pointer to the calibration data structure. * * @return Compensated pressure data. * @retval Compensated pressure data in double. */ static double compensate_pressure(const struct bme280_uncomp_data *uncomp_data, const struct bme280_calib_data *calib_data); /*! * @brief This internal API is used to compensate the raw humidity data and * return the compensated humidity data in double data type. * * @param[in] uncomp_data : Contains the uncompensated humidity data. * @param[in] calib_data : Pointer to the calibration data structure. * * @return Compensated humidity data. * @retval Compensated humidity data in double. */ static double compensate_humidity(const struct bme280_uncomp_data *uncomp_data, const struct bme280_calib_data *calib_data); /*! * @brief This internal API is used to compensate the raw temperature data and * return the compensated temperature data in double data type. * * @param[in] uncomp_data : Contains the uncompensated temperature data. * @param[in] calib_data : Pointer to calibration data structure. * * @return Compensated temperature data. * @retval Compensated temperature data in double. */ static double compensate_temperature(const struct bme280_uncomp_data *uncomp_data, struct bme280_calib_data *calib_data); #else /*! * @brief This internal API is used to compensate the raw temperature data and * return the compensated temperature data in integer data type. * * @param[in] uncomp_data : Contains the uncompensated temperature data. * @param[in] calib_data : Pointer to calibration data structure. * * @return Compensated temperature data. * @retval Compensated temperature data in integer. */ static int32_t compensate_temperature(const struct bme280_uncomp_data *uncomp_data, struct bme280_calib_data *calib_data); /*! * @brief This internal API is used to compensate the raw pressure data and * return the compensated pressure data in integer data type. * * @param[in] uncomp_data : Contains the uncompensated pressure data. * @param[in] calib_data : Pointer to the calibration data structure. * * @return Compensated pressure data. * @retval Compensated pressure data in integer. */ static uint32_t compensate_pressure(const struct bme280_uncomp_data *uncomp_data, const struct bme280_calib_data *calib_data); /*! * @brief This internal API is used to compensate the raw humidity data and * return the compensated humidity data in integer data type. * * @param[in] uncomp_data : Contains the uncompensated humidity data. * @param[in] calib_data : Pointer to the calibration data structure. * * @return Compensated humidity data. * @retval Compensated humidity data in integer. */ static uint32_t compensate_humidity(const struct bme280_uncomp_data *uncomp_data, const struct bme280_calib_data *calib_data); #endif /*! * @brief This internal API is used to identify the settings which the user * wants to modify in the sensor. * * @param[in] sub_settings : Contains the settings subset to identify particular * group of settings which the user is interested to change. * @param[in] desired_settings : Contains the user specified settings. * * @return Indicates whether user is interested to modify the settings which * are related to sub_settings. * @retval True -> User wants to modify this group of settings * @retval False -> User does not want to modify this group of settings */ static uint8_t are_settings_changed(uint8_t sub_settings, uint8_t desired_settings); /*! * @brief This API sets the humidity oversampling settings of the sensor. * * @param[in] dev : Structure instance of bme280_dev. * * @return Result of API execution status * @retval zero -> Success / +ve value -> Warning / -ve value -> Error */ static int8_t set_osr_humidity_settings(const struct bme280_settings *settings, const struct bme280_dev *dev); /*! * @brief This internal API sets the oversampling settings for pressure, * temperature and humidity in the sensor. * * @param[in] desired_settings : Variable used to select the settings which * are to be set. * @param[in] dev : Structure instance of bme280_dev. * * @return Result of API execution status * @retval zero -> Success / +ve value -> Warning / -ve value -> Error */ static int8_t set_osr_settings(uint8_t desired_settings, const struct bme280_settings *settings, const struct bme280_dev *dev); /*! * @brief This API sets the pressure and/or temperature oversampling settings * in the sensor according to the settings selected by the user. * * @param[in] dev : Structure instance of bme280_dev. * @param[in] desired_settings: variable to select the pressure and/or * temperature oversampling settings. * * @return Result of API execution status * @retval zero -> Success / +ve value -> Warning / -ve value -> Error */ static int8_t set_osr_press_temp_settings(uint8_t desired_settings, const struct bme280_settings *settings, const struct bme280_dev *dev); /*! * @brief This internal API fills the pressure oversampling settings provided by * the user in the data buffer so as to write in the sensor. * * @param[in] dev : Structure instance of bme280_dev. * @param[out] reg_data : Variable which is filled according to the pressure * oversampling data provided by the user. */ static void fill_osr_press_settings(uint8_t *reg_data, const struct bme280_settings *settings); /*! * @brief This internal API fills the temperature oversampling settings provided * by the user in the data buffer so as to write in the sensor. * * @param[in] dev : Structure instance of bme280_dev. * @param[out] reg_data : Variable which is filled according to the temperature * oversampling data provided by the user. */ static void fill_osr_temp_settings(uint8_t *reg_data, const struct bme280_settings *settings); /*! * @brief This internal API sets the filter and/or standby duration settings * in the sensor according to the settings selected by the user. * * @param[in] dev : Structure instance of bme280_dev. * @param[in] desired_settings : variable to select the filter and/or * standby duration settings. * * @return Result of API execution status * @retval zero -> Success / +ve value -> Warning / -ve value -> Error */ static int8_t set_filter_standby_settings(uint8_t desired_settings, const struct bme280_settings *settings, const struct bme280_dev *dev); /*! * @brief This internal API fills the filter settings provided by the user * in the data buffer so as to write in the sensor. * * @param[in] dev : Structure instance of bme280_dev. * @param[out] reg_data : Variable which is filled according to the filter * settings data provided by the user. */ static void fill_filter_settings(uint8_t *reg_data, const struct bme280_settings *settings); /*! * @brief This internal API fills the standby duration settings provided by the * user in the data buffer so as to write in the sensor. * * @param[in] dev : Structure instance of bme280_dev. * @param[out] reg_data : Variable which is filled according to the standby * settings data provided by the user. */ static void fill_standby_settings(uint8_t *reg_data, const struct bme280_settings *settings); /*! * @brief This internal API parse the oversampling(pressure, temperature * and humidity), filter and standby duration settings and store in the * device structure. * * @param[out] dev : Structure instance of bme280_dev. * @param[in] reg_data : Register data to be parsed. */ static void parse_device_settings(const uint8_t *reg_data, struct bme280_settings *settings); /*! * @brief This internal API reloads the already existing device settings in the * sensor after soft reset. * * @param[in] dev : Structure instance of bme280_dev. * @param[in] settings : Pointer variable which contains the settings to * be set in the sensor. * * @return Result of API execution status * @retval zero -> Success / +ve value -> Warning / -ve value -> Error */ static int8_t reload_device_settings(const struct bme280_settings *settings, const struct bme280_dev *dev); /****************** Global Function Definitions *******************************/ /*! * @brief This API is the entry point. * It reads the chip-id and calibration data from the sensor. */ int8_t bme280_init(struct bme280_dev *dev) { int8_t rslt; /* chip id read try count */ uint8_t try_count = 5; uint8_t chip_id = 0; /* Check for null pointer in the device structure*/ rslt = null_ptr_check(dev); /* Proceed if null check is fine */ if (rslt == BME280_OK) { while (try_count) { /* Read the chip-id of bme280 sensor */ rslt = bme280_get_regs(BME280_CHIP_ID_ADDR, &chip_id, 1, dev); /* Check for chip id validity */ if ((rslt == BME280_OK) && (chip_id == BME280_CHIP_ID)) { dev->chip_id = chip_id; /* Reset the sensor */ rslt = bme280_soft_reset(dev); if (rslt == BME280_OK) { /* Read the calibration data */ rslt = get_calib_data(dev); } break; } /* Wait for 1 ms */ dev->delay_ms(1); --try_count; } /* Chip id check failed */ if (!try_count) { rslt = BME280_E_DEV_NOT_FOUND; } } return rslt; } /*! * @brief This API reads the data from the given register address of the sensor. */ int8_t bme280_get_regs(uint8_t reg_addr, uint8_t *reg_data, uint16_t len, const struct bme280_dev *dev) { int8_t rslt; /* Check for null pointer in the device structure*/ rslt = null_ptr_check(dev); /* Proceed if null check is fine */ if (rslt == BME280_OK) { /* If interface selected is SPI */ if (dev->intf != BME280_I2C_INTF) { reg_addr = reg_addr | 0x80; } /* Read the data */ rslt = dev->read(dev->dev_id, reg_addr, reg_data, len); /* Check for communication error */ if (rslt != BME280_OK) { rslt = BME280_E_COMM_FAIL; } } return rslt; } /*! * @brief This API writes the given data to the register address * of the sensor. */ int8_t bme280_set_regs(uint8_t *reg_addr, const uint8_t *reg_data, uint8_t len, const struct bme280_dev *dev) { int8_t rslt; uint8_t temp_buff[20]; /* Typically not to write more than 10 registers */ if (len > 10) { len = 10; } uint16_t temp_len; uint8_t reg_addr_cnt; /* Check for null pointer in the device structure*/ rslt = null_ptr_check(dev); /* Check for arguments validity */ if ((rslt == BME280_OK) && (reg_addr != NULL) && (reg_data != NULL)) { if (len != 0) { temp_buff[0] = reg_data[0]; /* If interface selected is SPI */ if (dev->intf != BME280_I2C_INTF) { for (reg_addr_cnt = 0; reg_addr_cnt < len; reg_addr_cnt++) { reg_addr[reg_addr_cnt] = reg_addr[reg_addr_cnt] & 0x7F; } } /* Burst write mode */ if (len > 1) { /* Interleave register address w.r.t data for * burst write */ interleave_reg_addr(reg_addr, temp_buff, reg_data, len); temp_len = ((len * 2) - 1); } else { temp_len = len; } rslt = dev->write(dev->dev_id, reg_addr[0], temp_buff, temp_len); /* Check for communication error */ if (rslt != BME280_OK) { rslt = BME280_E_COMM_FAIL; } } else { rslt = BME280_E_INVALID_LEN; } } else { rslt = BME280_E_NULL_PTR; } return rslt; } /*! * @brief This API sets the oversampling, filter and standby duration * (normal mode) settings in the sensor. */ int8_t bme280_set_sensor_settings(uint8_t desired_settings, const struct bme280_dev *dev) { int8_t rslt; uint8_t sensor_mode; /* Check for null pointer in the device structure*/ rslt = null_ptr_check(dev); /* Proceed if null check is fine */ if (rslt == BME280_OK) { rslt = bme280_get_sensor_mode(&sensor_mode, dev); if ((rslt == BME280_OK) && (sensor_mode != BME280_SLEEP_MODE)) { rslt = put_device_to_sleep(dev); } if (rslt == BME280_OK) { /* Check if user wants to change oversampling * settings */ if (are_settings_changed(OVERSAMPLING_SETTINGS, desired_settings)) { rslt = set_osr_settings(desired_settings, &dev->settings, dev); } /* Check if user wants to change filter and/or * standby settings */ if ((rslt == BME280_OK) && are_settings_changed(FILTER_STANDBY_SETTINGS, desired_settings)) { rslt = set_filter_standby_settings(desired_settings, &dev->settings, dev); } } } return rslt; } /*! * @brief This API gets the oversampling, filter and standby duration * (normal mode) settings from the sensor. */ int8_t bme280_get_sensor_settings(struct bme280_dev *dev) { int8_t rslt; uint8_t reg_data[4]; /* Check for null pointer in the device structure*/ rslt = null_ptr_check(dev); /* Proceed if null check is fine */ if (rslt == BME280_OK) { rslt = bme280_get_regs(BME280_CTRL_HUM_ADDR, reg_data, 4, dev); if (rslt == BME280_OK) { parse_device_settings(reg_data, &dev->settings); } } return rslt; } /*! * @brief This API sets the power mode of the sensor. */ int8_t bme280_set_sensor_mode(uint8_t sensor_mode, const struct bme280_dev *dev) { int8_t rslt; uint8_t last_set_mode; /* Check for null pointer in the device structure*/ rslt = null_ptr_check(dev); if (rslt == BME280_OK) { rslt = bme280_get_sensor_mode(&last_set_mode, dev); /* If the sensor is not in sleep mode put the device to sleep * mode */ if ((rslt == BME280_OK) && (last_set_mode != BME280_SLEEP_MODE)) { rslt = put_device_to_sleep(dev); } /* Set the power mode */ if (rslt == BME280_OK) { rslt = write_power_mode(sensor_mode, dev); } } return rslt; } /*! * @brief This API gets the power mode of the sensor. */ int8_t bme280_get_sensor_mode(uint8_t *sensor_mode, const struct bme280_dev *dev) { int8_t rslt; /* Check for null pointer in the device structure*/ rslt = null_ptr_check(dev); if (rslt == BME280_OK) { /* Read the power mode register */ rslt = bme280_get_regs(BME280_PWR_CTRL_ADDR, sensor_mode, 1, dev); /* Assign the power mode in the device structure */ *sensor_mode = BME280_GET_BITS_POS_0(*sensor_mode, BME280_SENSOR_MODE); } return rslt; } /*! * @brief This API performs the soft reset of the sensor. */ int8_t bme280_soft_reset(const struct bme280_dev *dev) { int8_t rslt; uint8_t reg_addr = BME280_RESET_ADDR; uint8_t status_reg = 0; uint8_t try_run = 5; /* 0xB6 is the soft reset command */ uint8_t soft_rst_cmd = BME280_SOFT_RESET_COMMAND; /* Check for null pointer in the device structure*/ rslt = null_ptr_check(dev); /* Proceed if null check is fine */ if (rslt == BME280_OK) { /* Write the soft reset command in the sensor */ rslt = bme280_set_regs(®_addr, &soft_rst_cmd, 1, dev); if (rslt == BME280_OK) { /* If NVM not copied yet, Wait for NVM to copy */ do { /* As per data sheet - Table 1, startup time is 2 ms. */ dev->delay_ms(2); rslt = bme280_get_regs(BME280_STATUS_REG_ADDR, &status_reg, 1, dev); } while ((rslt == BME280_OK) && (try_run--) && (status_reg & BME280_STATUS_IM_UPDATE)); if (status_reg & BME280_STATUS_IM_UPDATE) { rslt = BME280_E_NVM_COPY_FAILED; } } } return rslt; } /*! * @brief This API reads the pressure, temperature and humidity data from the * sensor, compensates the data and store it in the bme280_data structure * instance passed by the user. */ int8_t bme280_get_sensor_data(uint8_t sensor_comp, struct bme280_data *comp_data, struct bme280_dev *dev) { int8_t rslt; /* Array to store the pressure, temperature and humidity data read from * the sensor */ uint8_t reg_data[BME280_P_T_H_DATA_LEN] = { 0 }; struct bme280_uncomp_data uncomp_data = { 0 }; /* Check for null pointer in the device structure*/ rslt = null_ptr_check(dev); if ((rslt == BME280_OK) && (comp_data != NULL)) { /* Read the pressure and temperature data from the sensor */ rslt = bme280_get_regs(BME280_DATA_ADDR, reg_data, BME280_P_T_H_DATA_LEN, dev); if (rslt == BME280_OK) { /* Parse the read data from the sensor */ bme280_parse_sensor_data(reg_data, &uncomp_data); /* Compensate the pressure and/or temperature and/or * humidity data from the sensor */ rslt = bme280_compensate_data(sensor_comp, &uncomp_data, comp_data, &dev->calib_data); } } else { rslt = BME280_E_NULL_PTR; } return rslt; } /*! * @brief This API is used to parse the pressure, temperature and * humidity data and store it in the bme280_uncomp_data structure instance. */ void bme280_parse_sensor_data(const uint8_t *reg_data, struct bme280_uncomp_data *uncomp_data) { /* Variables to store the sensor data */ uint32_t data_xlsb; uint32_t data_lsb; uint32_t data_msb; /* Store the parsed register values for pressure data */ data_msb = (uint32_t)reg_data[0] << 12; data_lsb = (uint32_t)reg_data[1] << 4; data_xlsb = (uint32_t)reg_data[2] >> 4; uncomp_data->pressure = data_msb | data_lsb | data_xlsb; /* Store the parsed register values for temperature data */ data_msb = (uint32_t)reg_data[3] << 12; data_lsb = (uint32_t)reg_data[4] << 4; data_xlsb = (uint32_t)reg_data[5] >> 4; uncomp_data->temperature = data_msb | data_lsb | data_xlsb; /* Store the parsed register values for humidity data */ data_msb = (uint32_t)reg_data[6] << 8; data_lsb = (uint32_t)reg_data[7]; uncomp_data->humidity = data_msb | data_lsb; } /*! * @brief This API is used to compensate the pressure and/or * temperature and/or humidity data according to the component selected * by the user. */ int8_t bme280_compensate_data(uint8_t sensor_comp, const struct bme280_uncomp_data *uncomp_data, struct bme280_data *comp_data, struct bme280_calib_data *calib_data) { int8_t rslt = BME280_OK; if ((uncomp_data != NULL) && (comp_data != NULL) && (calib_data != NULL)) { /* Initialize to zero */ comp_data->temperature = 0; comp_data->pressure = 0; comp_data->humidity = 0; /* If pressure or temperature component is selected */ if (sensor_comp & (BME280_PRESS | BME280_TEMP | BME280_HUM)) { /* Compensate the temperature data */ comp_data->temperature = compensate_temperature(uncomp_data, calib_data); } if (sensor_comp & BME280_PRESS) { /* Compensate the pressure data */ comp_data->pressure = compensate_pressure(uncomp_data, calib_data); } if (sensor_comp & BME280_HUM) { /* Compensate the humidity data */ comp_data->humidity = compensate_humidity(uncomp_data, calib_data); } } else { rslt = BME280_E_NULL_PTR; } return rslt; } /*! * @brief This API is used to calculate the maximum delay in milliseconds required for the * temperature/pressure/humidity(which ever at enabled) measurement to complete. */ uint32_t bme280_cal_meas_delay(const struct bme280_settings *settings) { uint32_t max_delay; uint8_t temp_osr; uint8_t pres_osr; uint8_t hum_osr; /*Array to map OSR config register value to actual OSR */ uint8_t osr_sett_to_act_osr[] = { 0, 1, 2, 4, 8, 16 }; /* Mapping osr settings to the actual osr values e.g. 0b101 -> osr X16 */ if (settings->osr_t <= 5) { temp_osr = osr_sett_to_act_osr[settings->osr_t]; } else { temp_osr = 16; } if (settings->osr_p <= 5) { pres_osr = osr_sett_to_act_osr[settings->osr_p]; } else { pres_osr = 16; } if (settings->osr_h <= 5) { hum_osr = osr_sett_to_act_osr[settings->osr_h]; } else { hum_osr = 16; } max_delay = (uint32_t)((BME280_MEAS_OFFSET + (BME280_MEAS_DUR * temp_osr) + ((BME280_MEAS_DUR * pres_osr) + BME280_PRES_HUM_MEAS_OFFSET) + ((BME280_MEAS_DUR * hum_osr) + BME280_PRES_HUM_MEAS_OFFSET)) / BME280_MEAS_SCALING_FACTOR); return max_delay; } /*! * @brief This internal API sets the oversampling settings for pressure, * temperature and humidity in the sensor. */ static int8_t set_osr_settings(uint8_t desired_settings, const struct bme280_settings *settings, const struct bme280_dev *dev) { int8_t rslt = BME280_W_INVALID_OSR_MACRO; if (desired_settings & BME280_OSR_HUM_SEL) { rslt = set_osr_humidity_settings(settings, dev); } if (desired_settings & (BME280_OSR_PRESS_SEL | BME280_OSR_TEMP_SEL)) { rslt = set_osr_press_temp_settings(desired_settings, settings, dev); } return rslt; } /*! * @brief This API sets the humidity oversampling settings of the sensor. */ static int8_t set_osr_humidity_settings(const struct bme280_settings *settings, const struct bme280_dev *dev) { int8_t rslt; uint8_t ctrl_hum; uint8_t ctrl_meas; uint8_t reg_addr = BME280_CTRL_HUM_ADDR; ctrl_hum = settings->osr_h & BME280_CTRL_HUM_MSK; /* Write the humidity control value in the register */ rslt = bme280_set_regs(®_addr, &ctrl_hum, 1, dev); /* Humidity related changes will be only effective after a * write operation to ctrl_meas register */ if (rslt == BME280_OK) { reg_addr = BME280_CTRL_MEAS_ADDR; rslt = bme280_get_regs(reg_addr, &ctrl_meas, 1, dev); if (rslt == BME280_OK) { rslt = bme280_set_regs(®_addr, &ctrl_meas, 1, dev); } } return rslt; } /*! * @brief This API sets the pressure and/or temperature oversampling settings * in the sensor according to the settings selected by the user. */ static int8_t set_osr_press_temp_settings(uint8_t desired_settings, const struct bme280_settings *settings, const struct bme280_dev *dev) { int8_t rslt; uint8_t reg_addr = BME280_CTRL_MEAS_ADDR; uint8_t reg_data; rslt = bme280_get_regs(reg_addr, ®_data, 1, dev); if (rslt == BME280_OK) { if (desired_settings & BME280_OSR_PRESS_SEL) { fill_osr_press_settings(®_data, settings); } if (desired_settings & BME280_OSR_TEMP_SEL) { fill_osr_temp_settings(®_data, settings); } /* Write the oversampling settings in the register */ rslt = bme280_set_regs(®_addr, ®_data, 1, dev); } return rslt; } /*! * @brief This internal API sets the filter and/or standby duration settings * in the sensor according to the settings selected by the user. */ static int8_t set_filter_standby_settings(uint8_t desired_settings, const struct bme280_settings *settings, const struct bme280_dev *dev) { int8_t rslt; uint8_t reg_addr = BME280_CONFIG_ADDR; uint8_t reg_data; rslt = bme280_get_regs(reg_addr, ®_data, 1, dev); if (rslt == BME280_OK) { if (desired_settings & BME280_FILTER_SEL) { fill_filter_settings(®_data, settings); } if (desired_settings & BME280_STANDBY_SEL) { fill_standby_settings(®_data, settings); } /* Write the oversampling settings in the register */ rslt = bme280_set_regs(®_addr, ®_data, 1, dev); } return rslt; } /*! * @brief This internal API fills the filter settings provided by the user * in the data buffer so as to write in the sensor. */ static void fill_filter_settings(uint8_t *reg_data, const struct bme280_settings *settings) { *reg_data = BME280_SET_BITS(*reg_data, BME280_FILTER, settings->filter); } /*! * @brief This internal API fills the standby duration settings provided by * the user in the data buffer so as to write in the sensor. */ static void fill_standby_settings(uint8_t *reg_data, const struct bme280_settings *settings) { *reg_data = BME280_SET_BITS(*reg_data, BME280_STANDBY, settings->standby_time); } /*! * @brief This internal API fills the pressure oversampling settings provided by * the user in the data buffer so as to write in the sensor. */ static void fill_osr_press_settings(uint8_t *reg_data, const struct bme280_settings *settings) { *reg_data = BME280_SET_BITS(*reg_data, BME280_CTRL_PRESS, settings->osr_p); } /*! * @brief This internal API fills the temperature oversampling settings * provided by the user in the data buffer so as to write in the sensor. */ static void fill_osr_temp_settings(uint8_t *reg_data, const struct bme280_settings *settings) { *reg_data = BME280_SET_BITS(*reg_data, BME280_CTRL_TEMP, settings->osr_t); } /*! * @brief This internal API parse the oversampling(pressure, temperature * and humidity), filter and standby duration settings and store in the * device structure. */ static void parse_device_settings(const uint8_t *reg_data, struct bme280_settings *settings) { settings->osr_h = BME280_GET_BITS_POS_0(reg_data[0], BME280_CTRL_HUM); settings->osr_p = BME280_GET_BITS(reg_data[2], BME280_CTRL_PRESS); settings->osr_t = BME280_GET_BITS(reg_data[2], BME280_CTRL_TEMP); settings->filter = BME280_GET_BITS(reg_data[3], BME280_FILTER); settings->standby_time = BME280_GET_BITS(reg_data[3], BME280_STANDBY); } /*! * @brief This internal API writes the power mode in the sensor. */ static int8_t write_power_mode(uint8_t sensor_mode, const struct bme280_dev *dev) { int8_t rslt; uint8_t reg_addr = BME280_PWR_CTRL_ADDR; /* Variable to store the value read from power mode register */ uint8_t sensor_mode_reg_val; /* Read the power mode register */ rslt = bme280_get_regs(reg_addr, &sensor_mode_reg_val, 1, dev); /* Set the power mode */ if (rslt == BME280_OK) { sensor_mode_reg_val = BME280_SET_BITS_POS_0(sensor_mode_reg_val, BME280_SENSOR_MODE, sensor_mode); /* Write the power mode in the register */ rslt = bme280_set_regs(®_addr, &sensor_mode_reg_val, 1, dev); } return rslt; } /*! * @brief This internal API puts the device to sleep mode. */ static int8_t put_device_to_sleep(const struct bme280_dev *dev) { int8_t rslt; uint8_t reg_data[4]; struct bme280_settings settings; rslt = bme280_get_regs(BME280_CTRL_HUM_ADDR, reg_data, 4, dev); if (rslt == BME280_OK) { parse_device_settings(reg_data, &settings); rslt = bme280_soft_reset(dev); if (rslt == BME280_OK) { rslt = reload_device_settings(&settings, dev); } } return rslt; } /*! * @brief This internal API reloads the already existing device settings in * the sensor after soft reset. */ static int8_t reload_device_settings(const struct bme280_settings *settings, const struct bme280_dev *dev) { int8_t rslt; rslt = set_osr_settings(BME280_ALL_SETTINGS_SEL, settings, dev); if (rslt == BME280_OK) { rslt = set_filter_standby_settings(BME280_ALL_SETTINGS_SEL, settings, dev); } return rslt; } #ifdef BME280_FLOAT_ENABLE /*! * @brief This internal API is used to compensate the raw temperature data and * return the compensated temperature data in double data type. */ static double compensate_temperature(const struct bme280_uncomp_data *uncomp_data, struct bme280_calib_data *calib_data) { double var1; double var2; double temperature; double temperature_min = -40; double temperature_max = 85; var1 = ((double)uncomp_data->temperature) / 16384.0 - ((double)calib_data->dig_t1) / 1024.0; var1 = var1 * ((double)calib_data->dig_t2); var2 = (((double)uncomp_data->temperature) / 131072.0 - ((double)calib_data->dig_t1) / 8192.0); var2 = (var2 * var2) * ((double)calib_data->dig_t3); calib_data->t_fine = (int32_t)(var1 + var2); temperature = (var1 + var2) / 5120.0; if (temperature < temperature_min) { temperature = temperature_min; } else if (temperature > temperature_max) { temperature = temperature_max; } return temperature; } /*! * @brief This internal API is used to compensate the raw pressure data and * return the compensated pressure data in double data type. */ static double compensate_pressure(const struct bme280_uncomp_data *uncomp_data, const struct bme280_calib_data *calib_data) { double var1; double var2; double var3; double pressure; double pressure_min = 30000.0; double pressure_max = 110000.0; var1 = ((double)calib_data->t_fine / 2.0) - 64000.0; var2 = var1 * var1 * ((double)calib_data->dig_p6) / 32768.0; var2 = var2 + var1 * ((double)calib_data->dig_p5) * 2.0; var2 = (var2 / 4.0) + (((double)calib_data->dig_p4) * 65536.0); var3 = ((double)calib_data->dig_p3) * var1 * var1 / 524288.0; var1 = (var3 + ((double)calib_data->dig_p2) * var1) / 524288.0; var1 = (1.0 + var1 / 32768.0) * ((double)calib_data->dig_p1); /* avoid exception caused by division by zero */ if (var1 > (0.0)) { pressure = 1048576.0 - (double) uncomp_data->pressure; pressure = (pressure - (var2 / 4096.0)) * 6250.0 / var1; var1 = ((double)calib_data->dig_p9) * pressure * pressure / 2147483648.0; var2 = pressure * ((double)calib_data->dig_p8) / 32768.0; pressure = pressure + (var1 + var2 + ((double)calib_data->dig_p7)) / 16.0; if (pressure < pressure_min) { pressure = pressure_min; } else if (pressure > pressure_max) { pressure = pressure_max; } } else /* Invalid case */ { pressure = pressure_min; } return pressure; } /*! * @brief This internal API is used to compensate the raw humidity data and * return the compensated humidity data in double data type. */ static double compensate_humidity(const struct bme280_uncomp_data *uncomp_data, const struct bme280_calib_data *calib_data) { double humidity; double humidity_min = 0.0; double humidity_max = 100.0; double var1; double var2; double var3; double var4; double var5; double var6; var1 = ((double)calib_data->t_fine) - 76800.0; var2 = (((double)calib_data->dig_h4) * 64.0 + (((double)calib_data->dig_h5) / 16384.0) * var1); var3 = uncomp_data->humidity - var2; var4 = ((double)calib_data->dig_h2) / 65536.0; var5 = (1.0 + (((double)calib_data->dig_h3) / 67108864.0) * var1); var6 = 1.0 + (((double)calib_data->dig_h6) / 67108864.0) * var1 * var5; var6 = var3 * var4 * (var5 * var6); humidity = var6 * (1.0 - ((double)calib_data->dig_h1) * var6 / 524288.0); if (humidity > humidity_max) { humidity = humidity_max; } else if (humidity < humidity_min) { humidity = humidity_min; } return humidity; } #else /*! * @brief This internal API is used to compensate the raw temperature data and * return the compensated temperature data in integer data type. */ static int32_t compensate_temperature(const struct bme280_uncomp_data *uncomp_data, struct bme280_calib_data *calib_data) { int32_t var1; int32_t var2; int32_t temperature; int32_t temperature_min = -4000; int32_t temperature_max = 8500; var1 = (int32_t)((uncomp_data->temperature / 8) - ((int32_t)calib_data->dig_t1 * 2)); var1 = (var1 * ((int32_t)calib_data->dig_t2)) / 2048; var2 = (int32_t)((uncomp_data->temperature / 16) - ((int32_t)calib_data->dig_t1)); var2 = (((var2 * var2) / 4096) * ((int32_t)calib_data->dig_t3)) / 16384; calib_data->t_fine = var1 + var2; temperature = (calib_data->t_fine * 5 + 128) / 256; if (temperature < temperature_min) { temperature = temperature_min; } else if (temperature > temperature_max) { temperature = temperature_max; } return temperature; } #ifndef BME280_32BIT_ENABLE /* 64 bit compensation for pressure data */ /*! * @brief This internal API is used to compensate the raw pressure data and * return the compensated pressure data in integer data type with higher * accuracy. */ static uint32_t compensate_pressure(const struct bme280_uncomp_data *uncomp_data, const struct bme280_calib_data *calib_data) { int64_t var1; int64_t var2; int64_t var3; int64_t var4; uint32_t pressure; uint32_t pressure_min = 3000000; uint32_t pressure_max = 11000000; var1 = ((int64_t)calib_data->t_fine) - 128000; var2 = var1 * var1 * (int64_t)calib_data->dig_p6; var2 = var2 + ((var1 * (int64_t)calib_data->dig_p5) * 131072); var2 = var2 + (((int64_t)calib_data->dig_p4) * 34359738368); var1 = ((var1 * var1 * (int64_t)calib_data->dig_p3) / 256) + ((var1 * ((int64_t)calib_data->dig_p2) * 4096)); var3 = ((int64_t)1) * 140737488355328; var1 = (var3 + var1) * ((int64_t)calib_data->dig_p1) / 8589934592; /* To avoid divide by zero exception */ if (var1 != 0) { var4 = 1048576 - uncomp_data->pressure; var4 = (((var4 * INT64_C(2147483648)) - var2) * 3125) / var1; var1 = (((int64_t)calib_data->dig_p9) * (var4 / 8192) * (var4 / 8192)) / 33554432; var2 = (((int64_t)calib_data->dig_p8) * var4) / 524288; var4 = ((var4 + var1 + var2) / 256) + (((int64_t)calib_data->dig_p7) * 16); pressure = (uint32_t)(((var4 / 2) * 100) / 128); if (pressure < pressure_min) { pressure = pressure_min; } else if (pressure > pressure_max) { pressure = pressure_max; } } else { pressure = pressure_min; } return pressure; } #else /* 32 bit compensation for pressure data */ /*! * @brief This internal API is used to compensate the raw pressure data and * return the compensated pressure data in integer data type. */ static uint32_t compensate_pressure(const struct bme280_uncomp_data *uncomp_data, const struct bme280_calib_data *calib_data) { int32_t var1; int32_t var2; int32_t var3; int32_t var4; uint32_t var5; uint32_t pressure; uint32_t pressure_min = 30000; uint32_t pressure_max = 110000; var1 = (((int32_t)calib_data->t_fine) / 2) - (int32_t)64000; var2 = (((var1 / 4) * (var1 / 4)) / 2048) * ((int32_t)calib_data->dig_p6); var2 = var2 + ((var1 * ((int32_t)calib_data->dig_p5)) * 2); var2 = (var2 / 4) + (((int32_t)calib_data->dig_p4) * 65536); var3 = (calib_data->dig_p3 * (((var1 / 4) * (var1 / 4)) / 8192)) / 8; var4 = (((int32_t)calib_data->dig_p2) * var1) / 2; var1 = (var3 + var4) / 262144; var1 = (((32768 + var1)) * ((int32_t)calib_data->dig_p1)) / 32768; /* avoid exception caused by division by zero */ if (var1) { var5 = (uint32_t)((uint32_t)1048576) - uncomp_data->pressure; pressure = ((uint32_t)(var5 - (uint32_t)(var2 / 4096))) * 3125; if (pressure < 0x80000000) { pressure = (pressure << 1) / ((uint32_t)var1); } else { pressure = (pressure / (uint32_t)var1) * 2; } var1 = (((int32_t)calib_data->dig_p9) * ((int32_t)(((pressure / 8) * (pressure / 8)) / 8192))) / 4096; var2 = (((int32_t)(pressure / 4)) * ((int32_t)calib_data->dig_p8)) / 8192; pressure = (uint32_t)((int32_t)pressure + ((var1 + var2 + calib_data->dig_p7) / 16)); if (pressure < pressure_min) { pressure = pressure_min; } else if (pressure > pressure_max) { pressure = pressure_max; } } else { pressure = pressure_min; } return pressure; } #endif /*! * @brief This internal API is used to compensate the raw humidity data and * return the compensated humidity data in integer data type. */ static uint32_t compensate_humidity(const struct bme280_uncomp_data *uncomp_data, const struct bme280_calib_data *calib_data) { int32_t var1; int32_t var2; int32_t var3; int32_t var4; int32_t var5; uint32_t humidity; uint32_t humidity_max = 102400; var1 = calib_data->t_fine - ((int32_t)76800); var2 = (int32_t)(uncomp_data->humidity * 16384); var3 = (int32_t)(((int32_t)calib_data->dig_h4) * 1048576); var4 = ((int32_t)calib_data->dig_h5) * var1; var5 = (((var2 - var3) - var4) + (int32_t)16384) / 32768; var2 = (var1 * ((int32_t)calib_data->dig_h6)) / 1024; var3 = (var1 * ((int32_t)calib_data->dig_h3)) / 2048; var4 = ((var2 * (var3 + (int32_t)32768)) / 1024) + (int32_t)2097152; var2 = ((var4 * ((int32_t)calib_data->dig_h2)) + 8192) / 16384; var3 = var5 * var2; var4 = ((var3 / 32768) * (var3 / 32768)) / 128; var5 = var3 - ((var4 * ((int32_t)calib_data->dig_h1)) / 16); var5 = (var5 < 0 ? 0 : var5); var5 = (var5 > 419430400 ? 419430400 : var5); humidity = (uint32_t)(var5 / 4096); if (humidity > humidity_max) { humidity = humidity_max; } return humidity; } #endif /*! * @brief This internal API reads the calibration data from the sensor, parse * it and store in the device structure. */ static int8_t get_calib_data(struct bme280_dev *dev) { int8_t rslt; uint8_t reg_addr = BME280_TEMP_PRESS_CALIB_DATA_ADDR; /* Array to store calibration data */ uint8_t calib_data[BME280_TEMP_PRESS_CALIB_DATA_LEN] = { 0 }; /* Read the calibration data from the sensor */ rslt = bme280_get_regs(reg_addr, calib_data, BME280_TEMP_PRESS_CALIB_DATA_LEN, dev); if (rslt == BME280_OK) { /* Parse temperature and pressure calibration data and store * it in device structure */ parse_temp_press_calib_data(calib_data, dev); reg_addr = BME280_HUMIDITY_CALIB_DATA_ADDR; /* Read the humidity calibration data from the sensor */ rslt = bme280_get_regs(reg_addr, calib_data, BME280_HUMIDITY_CALIB_DATA_LEN, dev); if (rslt == BME280_OK) { /* Parse humidity calibration data and store it in * device structure */ parse_humidity_calib_data(calib_data, dev); } } return rslt; } /*! * @brief This internal API interleaves the register address between the * register data buffer for burst write operation. */ static void interleave_reg_addr(const uint8_t *reg_addr, uint8_t *temp_buff, const uint8_t *reg_data, uint8_t len) { uint8_t index; for (index = 1; index < len; index++) { temp_buff[(index * 2) - 1] = reg_addr[index]; temp_buff[index * 2] = reg_data[index]; } } /*! * @brief This internal API is used to parse the temperature and * pressure calibration data and store it in device structure. */ static void parse_temp_press_calib_data(const uint8_t *reg_data, struct bme280_dev *dev) { struct bme280_calib_data *calib_data = &dev->calib_data; calib_data->dig_t1 = BME280_CONCAT_BYTES(reg_data[1], reg_data[0]); calib_data->dig_t2 = (int16_t)BME280_CONCAT_BYTES(reg_data[3], reg_data[2]); calib_data->dig_t3 = (int16_t)BME280_CONCAT_BYTES(reg_data[5], reg_data[4]); calib_data->dig_p1 = BME280_CONCAT_BYTES(reg_data[7], reg_data[6]); calib_data->dig_p2 = (int16_t)BME280_CONCAT_BYTES(reg_data[9], reg_data[8]); calib_data->dig_p3 = (int16_t)BME280_CONCAT_BYTES(reg_data[11], reg_data[10]); calib_data->dig_p4 = (int16_t)BME280_CONCAT_BYTES(reg_data[13], reg_data[12]); calib_data->dig_p5 = (int16_t)BME280_CONCAT_BYTES(reg_data[15], reg_data[14]); calib_data->dig_p6 = (int16_t)BME280_CONCAT_BYTES(reg_data[17], reg_data[16]); calib_data->dig_p7 = (int16_t)BME280_CONCAT_BYTES(reg_data[19], reg_data[18]); calib_data->dig_p8 = (int16_t)BME280_CONCAT_BYTES(reg_data[21], reg_data[20]); calib_data->dig_p9 = (int16_t)BME280_CONCAT_BYTES(reg_data[23], reg_data[22]); calib_data->dig_h1 = reg_data[25]; } /*! * @brief This internal API is used to parse the humidity calibration data * and store it in device structure. */ static void parse_humidity_calib_data(const uint8_t *reg_data, struct bme280_dev *dev) { struct bme280_calib_data *calib_data = &dev->calib_data; int16_t dig_h4_lsb; int16_t dig_h4_msb; int16_t dig_h5_lsb; int16_t dig_h5_msb; calib_data->dig_h2 = (int16_t)BME280_CONCAT_BYTES(reg_data[1], reg_data[0]); calib_data->dig_h3 = reg_data[2]; dig_h4_msb = (int16_t)(int8_t)reg_data[3] * 16; dig_h4_lsb = (int16_t)(reg_data[4] & 0x0F); calib_data->dig_h4 = dig_h4_msb | dig_h4_lsb; dig_h5_msb = (int16_t)(int8_t)reg_data[5] * 16; dig_h5_lsb = (int16_t)(reg_data[4] >> 4); calib_data->dig_h5 = dig_h5_msb | dig_h5_lsb; calib_data->dig_h6 = (int8_t)reg_data[6]; } /*! * @brief This internal API is used to identify the settings which the user * wants to modify in the sensor. */ static uint8_t are_settings_changed(uint8_t sub_settings, uint8_t desired_settings) { uint8_t settings_changed = FALSE; if (sub_settings & desired_settings) { /* User wants to modify this particular settings */ settings_changed = TRUE; } else { /* User don't want to modify this particular settings */ settings_changed = FALSE; } return settings_changed; } /*! * @brief This internal API is used to validate the device structure pointer for * null conditions. */ static int8_t null_ptr_check(const struct bme280_dev *dev) { int8_t rslt; if ((dev == NULL) || (dev->read == NULL) || (dev->write == NULL) || (dev->delay_ms == NULL)) { /* Device structure pointer is not valid */ rslt = BME280_E_NULL_PTR; } else { /* Device structure is fine */ rslt = BME280_OK; } return rslt; }