diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/driver/bme280.cc | 1178 |
1 files changed, 1178 insertions, 0 deletions
diff --git a/src/driver/bme280.cc b/src/driver/bme280.cc new file mode 100644 index 0000000..69ef445 --- /dev/null +++ b/src/driver/bme280.cc @@ -0,0 +1,1178 @@ +/*
+ * /\
+ * / \
+ * / !! \
+ * /______\
+ *
+ * In order to use the I2C interface, CSB needs to be pulled up before turning
+ * on VDDIO (and after VDD). On most BME280 breakout boards sold on
+ * AliExpress and similar sites, VDD and VDDIO are connected and there is only
+ * one external VCC input, so following the power sequence outlined in the
+ * datasheet is not possible. Additionally, the pull-up resistor connecting
+ * CSB to VCC may delay logic high level on CSB long enough for the BM280
+ * to start in SPI mode.
+ *
+ * In this case, you should connect (or power up, when using GPIO power)
+ * breakout board pins in the following order:
+ * * GND, SDA, SCLD
+ * * CSB to 3V3
+ * * VDD to 3V3
+ */
+
+/**\mainpage
+ * Copyright (C) 2018 - 2019 Bosch Sensortec GmbH
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 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.
+ *
+ * Neither the name of the copyright holder nor the names of the
+ * 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 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
+ *
+ * The information provided is believed to be accurate and reliable.
+ * The copyright holder assumes no responsibility
+ * for the consequences of use
+ * of such information nor for any infringement of patents or
+ * other rights of third parties which may result from its use.
+ * No license is granted by implication or otherwise under any patent or
+ * patent rights of the copyright holder.
+ *
+ * File bme280.c
+ * Date 26 Aug 2019
+ * Version 3.3.7
+ *
+ */
+
+/*! @file bme280.c
+ * @brief Sensor driver for BME280 sensor
+ */
+#include "driver/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)
+
+
+/****************** 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()
+{
+ 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();
+
+ /* Proceed if null check is fine */
+ if (rslt == BME280_OK)
+ {
+ while (try_count)
+ {
+ /* Read the chip-id of bme280 sensor */
+ rslt = get_regs(BME280_CHIP_ID_ADDR, &chip_id, 1);
+
+ /* Check for chip id validity */
+ if ((rslt == BME280_OK) && (chip_id == BME280_CHIP_ID))
+ {
+ /* Reset the sensor */
+ rslt = soft_reset();
+ if (rslt == BME280_OK)
+ {
+ /* Read the calibration data */
+ rslt = get_calib_data();
+ }
+ break;
+ }
+
+ /* Wait for 1 ms */
+ 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)
+{
+ int8_t rslt;
+
+ /* Check for null pointer in the device structure*/
+ rslt = null_ptr_check();
+
+ /* Proceed if null check is fine */
+ if (rslt == BME280_OK)
+ {
+ /* If interface selected is SPI */
+ if (intf != BME280_I2C_INTF)
+ {
+ reg_addr = reg_addr | 0x80;
+ }
+
+ /* Read the data */
+ rslt = read(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)
+{
+ 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();
+
+ /* 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 (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 = write(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)
+{
+ int8_t rslt;
+ uint8_t sensor_mode;
+
+ /* Check for null pointer in the device structure*/
+ rslt = null_ptr_check();
+
+ /* Proceed if null check is fine */
+ if (rslt == BME280_OK)
+ {
+ rslt = get_sensor_mode(&sensor_mode);
+ if ((rslt == BME280_OK) && (sensor_mode != BME280_SLEEP_MODE))
+ {
+ rslt = put_device_to_sleep();
+ }
+ 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);
+ }
+
+ /* 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);
+ }
+ }
+ }
+
+ return rslt;
+}
+
+/*!
+ * @brief This API gets the oversampling, filter and standby duration
+ * (normal mode) settings from the sensor.
+ */
+int8_t BME280::get_sensor_settings()
+{
+ int8_t rslt;
+ uint8_t reg_data[4];
+
+ /* Check for null pointer in the device structure*/
+ rslt = null_ptr_check();
+
+ /* Proceed if null check is fine */
+ if (rslt == BME280_OK)
+ {
+ rslt = get_regs(BME280_CTRL_HUM_ADDR, reg_data, 4);
+ if (rslt == BME280_OK)
+ {
+ parse_device_settings(reg_data, &settings);
+ }
+ }
+
+ return rslt;
+}
+
+/*!
+ * @brief This API sets the power mode of the sensor.
+ */
+int8_t BME280::set_sensor_mode(uint8_t sensor_mode)
+{
+ int8_t rslt;
+ uint8_t last_set_mode;
+
+ /* Check for null pointer in the device structure*/
+ rslt = null_ptr_check();
+ if (rslt == BME280_OK)
+ {
+ rslt = get_sensor_mode(&last_set_mode);
+
+ /* 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();
+ }
+
+ /* Set the power mode */
+ if (rslt == BME280_OK)
+ {
+ rslt = write_power_mode(sensor_mode);
+ }
+ }
+
+ return rslt;
+}
+
+/*!
+ * @brief This API gets the power mode of the sensor.
+ */
+int8_t BME280::get_sensor_mode(uint8_t *sensor_mode)
+{
+ int8_t rslt;
+
+ /* Check for null pointer in the device structure*/
+ rslt = null_ptr_check();
+ if (rslt == BME280_OK)
+ {
+ /* Read the power mode register */
+ rslt = get_regs(BME280_PWR_CTRL_ADDR, sensor_mode, 1);
+
+ /* 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()
+{
+ 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();
+
+ /* Proceed if null check is fine */
+ if (rslt == BME280_OK)
+ {
+ /* Write the soft reset command in the sensor */
+ rslt = set_regs(®_addr, &soft_rst_cmd, 1);
+
+ 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. */
+ delay_ms(2);
+ rslt = get_regs(BME280_STATUS_REG_ADDR, &status_reg, 1);
+ } 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)
+{
+ 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, 0, 0 };
+
+ /* Check for null pointer in the device structure*/
+ rslt = null_ptr_check();
+ if ((rslt == BME280_OK) && (comp_data != NULL))
+ {
+ /* Read the pressure and temperature data from the sensor */
+ rslt = get_regs(BME280_DATA_ADDR, reg_data, BME280_P_T_H_DATA_LEN);
+ 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 = compensate_data(sensor_comp, &uncomp_data, comp_data, &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 temperature data */
+ data_lsb = (uint32_t)reg_data[6] << 8;
+ data_msb = (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 internal API sets the oversampling settings for pressure,
+ * temperature and humidity in the sensor.
+ */
+int8_t BME280::set_osr_settings(uint8_t desired_settings,
+ const struct bme280_settings *settings)
+{
+ int8_t rslt = BME280_W_INVALID_OSR_MACRO;
+
+ if (desired_settings & BME280_OSR_HUM_SEL)
+ {
+ rslt = set_osr_humidity_settings(settings);
+ }
+ if (desired_settings & (BME280_OSR_PRESS_SEL | BME280_OSR_TEMP_SEL))
+ {
+ rslt = set_osr_press_temp_settings(desired_settings, settings);
+ }
+
+ return rslt;
+}
+
+/*!
+ * @brief This API sets the humidity oversampling settings of the sensor.
+ */
+int8_t BME280::set_osr_humidity_settings(const struct bme280_settings *settings)
+{
+ 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 = set_regs(®_addr, &ctrl_hum, 1);
+
+ /* 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 = get_regs(reg_addr, &ctrl_meas, 1);
+ if (rslt == BME280_OK)
+ {
+ rslt = set_regs(®_addr, &ctrl_meas, 1);
+ }
+ }
+
+ return rslt;
+}
+
+/*!
+ * @brief This API sets the pressure and/or temperature oversampling settings
+ * in the sensor according to the settings selected by the user.
+ */
+int8_t BME280::set_osr_press_temp_settings(uint8_t desired_settings,
+ const struct bme280_settings *settings)
+{
+ int8_t rslt;
+ uint8_t reg_addr = BME280_CTRL_MEAS_ADDR;
+ uint8_t reg_data;
+
+ rslt = BME280::get_regs(reg_addr, ®_data, 1);
+ 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);
+ }
+
+ 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.
+ */
+int8_t BME280::set_filter_standby_settings(uint8_t desired_settings,
+ const struct bme280_settings *settings)
+{
+ int8_t rslt;
+ uint8_t reg_addr = BME280_CONFIG_ADDR;
+ uint8_t reg_data;
+
+ rslt = get_regs(reg_addr, ®_data, 1);
+ 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 = set_regs(®_addr, ®_data, 1);
+ }
+
+ 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.
+ */
+void BME280::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.
+ */
+void BME280::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.
+ */
+void BME280::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.
+ */
+void BME280::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.
+ */
+void BME280::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.
+ */
+int8_t BME280::write_power_mode(uint8_t sensor_mode)
+{
+ 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 = get_regs(reg_addr, &sensor_mode_reg_val, 1);
+
+ /* 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 = set_regs(®_addr, &sensor_mode_reg_val, 1);
+ }
+
+ return rslt;
+}
+
+/*!
+ * @brief This internal API puts the device to sleep mode.
+ */
+int8_t BME280::put_device_to_sleep()
+{
+ int8_t rslt;
+ uint8_t reg_data[4];
+ struct bme280_settings settings;
+
+ rslt = get_regs(BME280_CTRL_HUM_ADDR, reg_data, 4);
+ if (rslt == BME280_OK)
+ {
+ parse_device_settings(reg_data, &settings);
+ rslt = soft_reset();
+ if (rslt == BME280_OK)
+ {
+ rslt = reload_device_settings(&settings);
+ }
+ }
+
+ return rslt;
+}
+
+/*!
+ * @brief This internal API reloads the already existing device settings in
+ * the sensor after soft reset.
+ */
+int8_t BME280::reload_device_settings(const struct bme280_settings *settings)
+{
+ int8_t rslt;
+
+ rslt = set_osr_settings(BME280_ALL_SETTINGS_SEL, settings);
+ if (rslt == BME280_OK)
+ {
+ rslt = set_filter_standby_settings(BME280_ALL_SETTINGS_SEL, settings);
+ }
+
+ 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.
+ */
+double BME280::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.
+ */
+double BME280::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)
+ {
+ 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.
+ */
+double BME280::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.
+ */
+int32_t BME280::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;
+}
+#ifdef BME280_64BIT_ENABLE
+
+/*!
+ * @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.
+ */
+uint32_t BME280::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
+
+/*!
+ * @brief This internal API is used to compensate the raw pressure data and
+ * return the compensated pressure data in integer data type.
+ */
+uint32_t BME280::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.
+ */
+uint32_t BME280::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.
+ */
+int8_t BME280::get_calib_data()
+{
+ 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 = get_regs(reg_addr, calib_data, BME280_TEMP_PRESS_CALIB_DATA_LEN);
+ if (rslt == BME280_OK)
+ {
+ /* Parse temperature and pressure calibration data and store
+ * it in device structure
+ */
+ parse_temp_press_calib_data(calib_data);
+ reg_addr = BME280_HUMIDITY_CALIB_DATA_ADDR;
+
+ /* Read the humidity calibration data from the sensor */
+ rslt = get_regs(reg_addr, calib_data, BME280_HUMIDITY_CALIB_DATA_LEN);
+ if (rslt == BME280_OK)
+ {
+ /* Parse humidity calibration data and store it in
+ * device structure
+ */
+ parse_humidity_calib_data(calib_data);
+ }
+ }
+
+ return rslt;
+}
+
+/*!
+ * @brief This internal API interleaves the register address between the
+ * register data buffer for burst write operation.
+ */
+void BME280::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.
+ */
+void BME280::parse_temp_press_calib_data(const uint8_t *reg_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.
+ */
+void BME280::parse_humidity_calib_data(const uint8_t *reg_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.
+ */
+uint8_t BME280::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.
+ */
+int8_t BME280::null_ptr_check()
+{
+ int8_t rslt;
+
+ if ((read == NULL) || (write == NULL) || (delay_ms == NULL))
+ {
+ /* Device structure pointer is not valid */
+ rslt = BME280_E_NULL_PTR;
+ }
+ else
+ {
+ /* Device structure is fine */
+ rslt = BME280_OK;
+ }
+
+ return rslt;
+}
+
+BME280 bme280(BME280_I2C_ADDR_PRIM);
|