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bme280.c
1571 lines (1372 loc) · 49.9 KB
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bme280.c
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/**
* 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 2020-12-17
* @version v3.5.1
*
*/
/*! @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 0 -> Success.
* @retval > 0 -> Warning.
* @retval < 0 -> Fail.
*
*/
static int8_t put_device_to_sleep(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 0 -> Success.
* @retval > 0 -> Warning.
* @retval < 0 -> Fail.
*
*/
static int8_t write_power_mode(uint8_t sensor_mode, 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 0 -> Success.
* @retval > 0 -> Warning.
* @retval < 0 -> Fail.
*
*/
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, uint32_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 0 -> Success.
* @retval > 0 -> Warning.
* @retval < 0 -> Fail.
*
*/
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);
/*!
* @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.
* @return True -> User wants to modify this group of settings
* @return 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 over sampling settings of the sensor.
*
* @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 0 -> Success.
* @retval > 0 -> Warning.
* @retval < 0 -> Fail.
*
*/
static int8_t set_osr_humidity_settings(const struct bme280_settings *settings, 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] settings : Pointer variable which contains the settings to
* be set in the sensor.
* @param[in] dev : Structure instance of bme280_dev.
*
* @return Result of API execution status
*
* @retval 0 -> Success.
* @retval > 0 -> Warning.
* @retval < 0 -> Fail.
*
*/
static int8_t set_osr_settings(uint8_t desired_settings, const struct bme280_settings *settings,
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.
* @param[in] settings : Pointer variable which contains the settings to
* be set in the sensor.
*
* @return Result of API execution status
*
* @retval 0 -> Success.
* @retval > 0 -> Warning.
* @retval < 0 -> Fail.
*
*/
static int8_t set_osr_press_temp_settings(uint8_t desired_settings,
const struct bme280_settings *settings,
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] settings : Pointer variable which contains the settings to
* be set in the sensor.
* @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] settings : Pointer variable which contains the settings to
* be set in the sensor.
* @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] settings : Pointer variable which contains the settings to
* be set in the sensor.
* @param[in] settings : Structure instance of bme280_settings.
*
* @return Result of API execution status
*
* @retval 0 -> Success.
* @retval > 0 -> Warning.
* @retval < 0 -> Fail.
*
*/
static int8_t set_filter_standby_settings(uint8_t desired_settings,
const struct bme280_settings *settings,
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] settings : Pointer variable which contains the settings to
* be set in the sensor.
* @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] settings : Pointer variable which contains the settings to
* be set in the sensor.
* @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[in] settings : Pointer variable which contains the settings to
* be get in the sensor.
* @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 API is used to parse the pressure, temperature and
* humidity data and store it in the bme280_uncomp_data structure instance.
*
* @param[in] reg_data : Contains register data which needs to be parsed
* @param[out] uncomp_data : Contains the uncompensated pressure, temperature and humidity data
*/
static void parse_sensor_data(const uint8_t *reg_data, struct bme280_uncomp_data *uncomp_data);
/*!
* @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 0 -> Success.
* @retval > 0 -> Warning.
* @retval < 0 -> Fail.
*
*/
static int8_t reload_device_settings(const struct bme280_settings *settings, struct bme280_dev *dev);
#ifdef BME280_DOUBLE_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 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 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 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 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 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 in integer.
*
*/
static uint32_t compensate_humidity(const struct bme280_uncomp_data *uncomp_data,
const struct bme280_calib_data *calib_data);
#endif
/****************** 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;
uint8_t chip_id = 0;
/* Read the chip-id of bme280 sensor */
rslt = bme280_get_regs(BME280_REG_CHIP_ID, &chip_id, 1, dev);
/* Check for chip id validity */
if (rslt == BME280_OK)
{
if (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);
}
}
else
{
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, uint32_t len, struct bme280_dev *dev)
{
int8_t rslt;
/* Check for null pointer in the device structure */
rslt = null_ptr_check(dev);
if ((rslt == BME280_OK) && (reg_data != NULL))
{
/* If interface selected is SPI */
if (dev->intf != BME280_I2C_INTF)
{
reg_addr = reg_addr | 0x80;
}
/* Read the data */
dev->intf_rslt = dev->read(reg_addr, reg_data, len, dev->intf_ptr);
/* Check for communication error */
if (dev->intf_rslt != BME280_INTF_RET_SUCCESS)
{
rslt = BME280_E_COMM_FAIL;
}
}
else
{
rslt = BME280_E_NULL_PTR;
}
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, uint32_t len, struct bme280_dev *dev)
{
int8_t rslt;
uint8_t temp_buff[20]; /* Typically not to write more than 10 registers */
uint32_t temp_len;
uint32_t reg_addr_cnt;
if (len > BME280_MAX_LEN)
{
len = BME280_MAX_LEN;
}
/* 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;
}
dev->intf_rslt = dev->write(reg_addr[0], temp_buff, temp_len, dev->intf_ptr);
/* Check for communication error */
if (dev->intf_rslt != BME280_INTF_RET_SUCCESS)
{
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_settings *settings,
struct bme280_dev *dev)
{
int8_t rslt;
uint8_t sensor_mode;
if (settings != NULL)
{
rslt = bme280_get_sensor_mode(&sensor_mode, dev);
if ((rslt == BME280_OK) && (sensor_mode != BME280_POWERMODE_SLEEP))
{
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, 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, settings, dev);
}
}
}
else
{
rslt = BME280_E_NULL_PTR;
}
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_settings *settings, struct bme280_dev *dev)
{
int8_t rslt;
uint8_t reg_data[4];
if (settings != NULL)
{
rslt = bme280_get_regs(BME280_REG_CTRL_HUM, reg_data, 4, dev);
if (rslt == BME280_OK)
{
parse_device_settings(reg_data, settings);
}
}
else
{
rslt = BME280_E_NULL_PTR;
}
return rslt;
}
/*!
* @brief This API sets the power mode of the sensor.
*/
int8_t bme280_set_sensor_mode(uint8_t sensor_mode, struct bme280_dev *dev)
{
int8_t rslt;
uint8_t last_set_mode;
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_POWERMODE_SLEEP))
{
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, struct bme280_dev *dev)
{
int8_t rslt;
if (sensor_mode != NULL)
{
/* Read the power mode register */
rslt = bme280_get_regs(BME280_REG_PWR_CTRL, sensor_mode, 1, dev);
/* Assign the power mode to variable */
*sensor_mode = BME280_GET_BITS_POS_0(*sensor_mode, BME280_SENSOR_MODE);
}
else
{
rslt = BME280_E_NULL_PTR;
}
return rslt;
}
/*!
* @brief This API performs the soft reset of the sensor.
*/
int8_t bme280_soft_reset(struct bme280_dev *dev)
{
int8_t rslt;
uint8_t reg_addr = BME280_REG_RESET;
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;
/* 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_us(BME280_STARTUP_DELAY, dev->intf_ptr);
rslt = bme280_get_regs(BME280_REG_STATUS, &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_LEN_P_T_H_DATA] = { 0 };
struct bme280_uncomp_data uncomp_data = { 0 };
if (comp_data != NULL)
{
/* Read the pressure and temperature data from the sensor */
rslt = bme280_get_regs(BME280_REG_DATA, reg_data, BME280_LEN_P_T_H_DATA, dev);
if (rslt == BME280_OK)
{
/* Parse the read data from the sensor */
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 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(whichever are enabled) measurement to complete.
*/
int8_t bme280_cal_meas_delay(uint32_t *max_delay, const struct bme280_settings *settings)
{
int8_t rslt = BME280_OK;
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 };
if ((settings != NULL) && (max_delay != NULL))
{
/* Mapping osr settings to the actual osr values e.g. 0b101 -> osr X16 */
if (settings->osr_t <= BME280_OVERSAMPLING_16X)
{
temp_osr = osr_sett_to_act_osr[settings->osr_t];
}
else
{
temp_osr = BME280_OVERSAMPLING_MAX;
}
if (settings->osr_p <= BME280_OVERSAMPLING_16X)
{
pres_osr = osr_sett_to_act_osr[settings->osr_p];
}
else
{
pres_osr = BME280_OVERSAMPLING_MAX;
}
if (settings->osr_h <= BME280_OVERSAMPLING_16X)
{
hum_osr = osr_sett_to_act_osr[settings->osr_h];
}
else
{
hum_osr = BME280_OVERSAMPLING_MAX;
}
(*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)));
}
else
{
rslt = BME280_E_NULL_PTR;
}
return rslt;
}
/****************************************************************************/
/**\name INTERNAL APIs */
/*!
* @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, struct bme280_dev *dev)
{
int8_t rslt = BME280_W_INVALID_OSR_MACRO;
if (desired_settings & BME280_SEL_OSR_HUM)
{
rslt = set_osr_humidity_settings(settings, dev);
}
if (desired_settings & (BME280_SEL_OSR_PRESS | BME280_SEL_OSR_TEMP))
{
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, struct bme280_dev *dev)
{
int8_t rslt;
uint8_t ctrl_hum;
uint8_t ctrl_meas;
uint8_t reg_addr = BME280_REG_CTRL_HUM;
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_REG_CTRL_MEAS;
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,
struct bme280_dev *dev)
{
int8_t rslt;
uint8_t reg_addr = BME280_REG_CTRL_MEAS;
uint8_t reg_data;
rslt = bme280_get_regs(reg_addr, ®_data, 1, dev);
if (rslt == BME280_OK)
{
if (desired_settings & BME280_SEL_OSR_PRESS)
{
fill_osr_press_settings(®_data, settings);
}
if (desired_settings & BME280_SEL_OSR_TEMP)
{
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,
struct bme280_dev *dev)
{
int8_t rslt;
uint8_t reg_addr = BME280_REG_CONFIG;
uint8_t reg_data;
rslt = bme280_get_regs(reg_addr, ®_data, 1, dev);
if (rslt == BME280_OK)
{
if (desired_settings & BME280_SEL_FILTER)
{
fill_filter_settings(®_data, settings);
}
if (desired_settings & BME280_SEL_STANDBY)
{
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);
}