Add Bosch SensorTec BME680 driver + utilities

3 files changed, 777 insertions, 0 deletions

diff --git a/include/driver/bme680.h b/include/driver/bme680.h
new file mode 100644
index 0000000..fdecbab
--- /dev/null
+++ b/include/driver/bme680.h
@@ -0,0 +1,225 @@
+/**

+ * Copyright (C) 2017 - 2018 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	bme680.h

+ * @date	19 Jun 2018

+ * @version	3.5.9

+ * @brief

+ *

+ */

+/*! @file bme680.h

+ @brief Sensor driver for BME680 sensor */

+/*!

+ * @defgroup BME680 SENSOR API

+ * @{*/

+#ifndef BME680_H_

+#define BME680_H_

+

+/*! CPP guard */

+#ifdef __cplusplus

+extern "C"

+{

+#endif

+

+/* Header includes */

+#include "driver/bme680_defs.h"

+

+/* function prototype declarations */

+/*!

+ *  @brief This API is the entry point.

+ *  It reads the chip-id and calibration data from the sensor.

+ *

+ *  @param[in,out] dev : Structure instance of bme680_dev

+ *

+ *  @return Result of API execution status

+ *  @retval zero -> Success / +ve value -> Warning / -ve value -> Error

+ */

+int8_t bme680_init(struct bme680_dev *dev);

+

+/*!

+ * @brief This API writes the given data to the register address

+ * of the sensor.

+ *

+ * @param[in] reg_addr : Register address from where the data to be written.

+ * @param[in] reg_data : Pointer to data buffer which is to be written

+ * in the sensor.

+ * @param[in] len : No of bytes of data to write..

+ * @param[in] dev : Structure instance of bme680_dev.

+ *

+ * @return Result of API execution status

+ * @retval zero -> Success / +ve value -> Warning / -ve value -> Error

+ */

+int8_t bme680_set_regs(const uint8_t *reg_addr, const uint8_t *reg_data, uint8_t len, struct bme680_dev *dev);

+

+/*!

+ * @brief This API reads the data from the given register address of the sensor.

+ *

+ * @param[in] reg_addr : Register address from where the data to be read

+ * @param[out] reg_data : Pointer to data buffer to store the read data.

+ * @param[in] len : No of bytes of data to be read.

+ * @param[in] dev : Structure instance of bme680_dev.

+ *

+ * @return Result of API execution status

+ * @retval zero -> Success / +ve value -> Warning / -ve value -> Error

+ */

+int8_t bme680_get_regs(uint8_t reg_addr, uint8_t *reg_data, uint16_t len, struct bme680_dev *dev);

+

+/*!

+ * @brief This API performs the soft reset of the sensor.

+ *

+ * @param[in] dev : Structure instance of bme680_dev.

+ *

+ * @return Result of API execution status

+ * @retval zero -> Success / +ve value -> Warning / -ve value -> Error.

+ */

+int8_t bme680_soft_reset(struct bme680_dev *dev);

+

+/*!

+ * @brief This API is used to set the power mode of the sensor.

+ *

+ * @param[in] dev : Structure instance of bme680_dev

+ * @note : Pass the value to bme680_dev.power_mode structure variable.

+ *

+ *  value	|	mode

+ * -------------|------------------

+ *	0x00	|	BME680_SLEEP_MODE

+ *	0x01	|	BME680_FORCED_MODE

+ *

+ * * @return Result of API execution status

+ * @retval zero -> Success / +ve value -> Warning / -ve value -> Error

+ */

+int8_t bme680_set_sensor_mode(struct bme680_dev *dev);

+

+/*!

+ * @brief This API is used to get the power mode of the sensor.

+ *

+ * @param[in] dev : Structure instance of bme680_dev

+ * @note : bme680_dev.power_mode structure variable hold the power mode.

+ *

+ *  value	|	mode

+ * ---------|------------------

+ *	0x00	|	BME680_SLEEP_MODE

+ *	0x01	|	BME680_FORCED_MODE

+ *

+ * @return Result of API execution status

+ * @retval zero -> Success / +ve value -> Warning / -ve value -> Error

+ */

+int8_t bme680_get_sensor_mode(struct bme680_dev *dev);

+

+/*!

+ * @brief This API is used to set the profile duration of the sensor.

+ *

+ * @param[in] dev	   : Structure instance of bme680_dev.

+ * @param[in] duration : Duration of the measurement in ms.

+ *

+ * @return Nothing

+ */

+void bme680_set_profile_dur(uint16_t duration, struct bme680_dev *dev);

+

+/*!

+ * @brief This API is used to get the profile duration of the sensor.

+ *

+ * @param[in] dev	   : Structure instance of bme680_dev.

+ * @param[in] duration : Duration of the measurement in ms.

+ *

+ * @return Nothing

+ */

+void bme680_get_profile_dur(uint16_t *duration, const struct bme680_dev *dev);

+

+/*!

+ * @brief This API reads the pressure, temperature and humidity and gas data

+ * from the sensor, compensates the data and store it in the bme680_data

+ * structure instance passed by the user.

+ *

+ * @param[out] data: Structure instance to hold the data.

+ * @param[in] dev : Structure instance of bme680_dev.

+ *

+ * @return Result of API execution status

+ * @retval zero -> Success / +ve value -> Warning / -ve value -> Error

+ */

+int8_t bme680_get_sensor_data(struct bme680_field_data *data, struct bme680_dev *dev);

+

+/*!

+ * @brief This API is used to set the oversampling, filter and T,P,H, gas selection

+ * settings in the sensor.

+ *

+ * @param[in] dev : Structure instance of bme680_dev.

+ * @param[in] desired_settings : Variable used to select the settings which

+ * are to be set in the sensor.

+ *

+ *	 Macros	                   |  Functionality

+ *---------------------------------|----------------------------------------------

+ *	BME680_OST_SEL             |    To set temperature oversampling.

+ *	BME680_OSP_SEL             |    To set pressure oversampling.

+ *	BME680_OSH_SEL             |    To set humidity oversampling.

+ *	BME680_GAS_MEAS_SEL        |    To set gas measurement setting.

+ *	BME680_FILTER_SEL          |    To set filter setting.

+ *	BME680_HCNTRL_SEL          |    To set humidity control setting.

+ *	BME680_RUN_GAS_SEL         |    To set run gas setting.

+ *	BME680_NBCONV_SEL          |    To set NB conversion setting.

+ *	BME680_GAS_SENSOR_SEL      |    To set all gas sensor related settings

+ *

+ * @note : Below are the macros to be used by the user for selecting the

+ * desired settings. User can do OR operation of these macros for configuring

+ * multiple settings.

+ *

+ * @return Result of API execution status

+ * @retval zero -> Success / +ve value -> Warning / -ve value -> Error.

+ */

+int8_t bme680_set_sensor_settings(uint16_t desired_settings, struct bme680_dev *dev);

+

+/*!

+ * @brief This API is used to get the oversampling, filter and T,P,H, gas selection

+ * settings in the sensor.

+ *

+ * @param[in] dev : Structure instance of bme680_dev.

+ * @param[in] desired_settings : Variable used to select the settings which

+ * are to be get from the sensor.

+ *

+ * @return Result of API execution status

+ * @retval zero -> Success / +ve value -> Warning / -ve value -> Error.

+ */

+int8_t bme680_get_sensor_settings(uint16_t desired_settings, struct bme680_dev *dev);

+#ifdef __cplusplus

+}

+#endif /* End of CPP guard */

+#endif /* BME680_H_ */

+/** @}*/

diff --git a/include/driver/bme680_defs.h b/include/driver/bme680_defs.h
new file mode 100644
index 0000000..b7c52d8
--- /dev/null
+++ b/include/driver/bme680_defs.h
@@ -0,0 +1,545 @@
+/**

+ * Copyright (C) 2017 - 2018 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	bme680_defs.h

+ * @date	19 Jun 2018

+ * @version	3.5.9

+ * @brief

+ *

+ */

+

+/*! @file bme680_defs.h

+ @brief Sensor driver for BME680 sensor */

+/*!

+ * @defgroup BME680 SENSOR API

+ * @brief

+ * @{*/

+#ifndef BME680_DEFS_H_

+#define BME680_DEFS_H_

+

+/********************************************************/

+/* header includes */

+#ifdef __KERNEL__

+#include <linux/types.h>

+#include <linux/kernel.h>

+#else

+#include <stdint.h>

+#include <stddef.h>

+#endif

+

+/******************************************************************************/

+/*! @name		Common macros					      */

+/******************************************************************************/

+

+#if !defined(UINT8_C) && !defined(INT8_C)

+#define INT8_C(x)       S8_C(x)

+#define UINT8_C(x)      U8_C(x)

+#endif

+

+#if !defined(UINT16_C) && !defined(INT16_C)

+#define INT16_C(x)      S16_C(x)

+#define UINT16_C(x)     U16_C(x)

+#endif

+

+#if !defined(INT32_C) && !defined(UINT32_C)

+#define INT32_C(x)      S32_C(x)

+#define UINT32_C(x)     U32_C(x)

+#endif

+

+#if !defined(INT64_C) && !defined(UINT64_C)

+#define INT64_C(x)      S64_C(x)

+#define UINT64_C(x)     U64_C(x)

+#endif

+

+/**@}*/

+

+/**\name C standard macros */

+#ifndef NULL

+#ifdef __cplusplus

+#define NULL   0

+#else

+#define NULL   ((void *) 0)

+#endif

+#endif

+

+/** BME680 configuration macros */

+/** Enable or un-comment the macro to provide floating point data output */

+#ifndef BME680_FLOAT_POINT_COMPENSATION

+/* #define BME680_FLOAT_POINT_COMPENSATION */

+#endif

+

+/** BME680 General config */

+#define BME680_POLL_PERIOD_MS		UINT8_C(10)

+

+/** BME680 I2C addresses */

+#define BME680_I2C_ADDR_PRIMARY		UINT8_C(0x76)

+#define BME680_I2C_ADDR_SECONDARY	UINT8_C(0x77)

+

+/** BME680 unique chip identifier */

+#define BME680_CHIP_ID  UINT8_C(0x61)

+

+/** BME680 coefficients related defines */

+#define BME680_COEFF_SIZE		UINT8_C(41)

+#define BME680_COEFF_ADDR1_LEN		UINT8_C(25)

+#define BME680_COEFF_ADDR2_LEN		UINT8_C(16)

+

+/** BME680 field_x related defines */

+#define BME680_FIELD_LENGTH		UINT8_C(15)

+#define BME680_FIELD_ADDR_OFFSET	UINT8_C(17)

+

+/** Soft reset command */

+#define BME680_SOFT_RESET_CMD   UINT8_C(0xb6)

+

+/** Error code definitions */

+#define BME680_OK		INT8_C(0)

+/* Errors */

+#define BME680_E_NULL_PTR		    INT8_C(-1)

+#define BME680_E_COM_FAIL		    INT8_C(-2)

+#define BME680_E_DEV_NOT_FOUND		INT8_C(-3)

+#define BME680_E_INVALID_LENGTH		INT8_C(-4)

+

+/* Warnings */

+#define BME680_W_DEFINE_PWR_MODE	INT8_C(1)

+#define BME680_W_NO_NEW_DATA        INT8_C(2)

+

+/* Info's */

+#define BME680_I_MIN_CORRECTION		UINT8_C(1)

+#define BME680_I_MAX_CORRECTION		UINT8_C(2)

+

+/** Register map */

+/** Other coefficient's address */

+#define BME680_ADDR_RES_HEAT_VAL_ADDR	UINT8_C(0x00)

+#define BME680_ADDR_RES_HEAT_RANGE_ADDR	UINT8_C(0x02)

+#define BME680_ADDR_RANGE_SW_ERR_ADDR	UINT8_C(0x04)

+#define BME680_ADDR_SENS_CONF_START	UINT8_C(0x5A)

+#define BME680_ADDR_GAS_CONF_START	UINT8_C(0x64)

+

+/** Field settings */

+#define BME680_FIELD0_ADDR		UINT8_C(0x1d)

+

+/** Heater settings */

+#define BME680_RES_HEAT0_ADDR		UINT8_C(0x5a)

+#define BME680_GAS_WAIT0_ADDR		UINT8_C(0x64)

+

+/** Sensor configuration registers */

+#define BME680_CONF_HEAT_CTRL_ADDR		UINT8_C(0x70)

+#define BME680_CONF_ODR_RUN_GAS_NBC_ADDR	UINT8_C(0x71)

+#define BME680_CONF_OS_H_ADDR			UINT8_C(0x72)

+#define BME680_MEM_PAGE_ADDR			UINT8_C(0xf3)

+#define BME680_CONF_T_P_MODE_ADDR		UINT8_C(0x74)

+#define BME680_CONF_ODR_FILT_ADDR		UINT8_C(0x75)

+

+/** Coefficient's address */

+#define BME680_COEFF_ADDR1	UINT8_C(0x89)

+#define BME680_COEFF_ADDR2	UINT8_C(0xe1)

+

+/** Chip identifier */

+#define BME680_CHIP_ID_ADDR	UINT8_C(0xd0)

+

+/** Soft reset register */

+#define BME680_SOFT_RESET_ADDR		UINT8_C(0xe0)

+

+/** Heater control settings */

+#define BME680_ENABLE_HEATER		UINT8_C(0x00)

+#define BME680_DISABLE_HEATER		UINT8_C(0x08)

+

+/** Gas measurement settings */

+#define BME680_DISABLE_GAS_MEAS		UINT8_C(0x00)

+#define BME680_ENABLE_GAS_MEAS		UINT8_C(0x01)

+

+/** Over-sampling settings */

+#define BME680_OS_NONE		UINT8_C(0)

+#define BME680_OS_1X		UINT8_C(1)

+#define BME680_OS_2X		UINT8_C(2)

+#define BME680_OS_4X		UINT8_C(3)

+#define BME680_OS_8X		UINT8_C(4)

+#define BME680_OS_16X		UINT8_C(5)

+

+/** IIR filter settings */

+#define BME680_FILTER_SIZE_0	UINT8_C(0)

+#define BME680_FILTER_SIZE_1	UINT8_C(1)

+#define BME680_FILTER_SIZE_3	UINT8_C(2)

+#define BME680_FILTER_SIZE_7	UINT8_C(3)

+#define BME680_FILTER_SIZE_15	UINT8_C(4)

+#define BME680_FILTER_SIZE_31	UINT8_C(5)

+#define BME680_FILTER_SIZE_63	UINT8_C(6)

+#define BME680_FILTER_SIZE_127	UINT8_C(7)

+

+/** Power mode settings */

+#define BME680_SLEEP_MODE	UINT8_C(0)

+#define BME680_FORCED_MODE	UINT8_C(1)

+

+/** Delay related macro declaration */

+#define BME680_RESET_PERIOD	UINT32_C(10)

+

+/** SPI memory page settings */

+#define BME680_MEM_PAGE0	UINT8_C(0x10)

+#define BME680_MEM_PAGE1	UINT8_C(0x00)

+

+/** Ambient humidity shift value for compensation */

+#define BME680_HUM_REG_SHIFT_VAL	UINT8_C(4)

+

+/** Run gas enable and disable settings */

+#define BME680_RUN_GAS_DISABLE	UINT8_C(0)

+#define BME680_RUN_GAS_ENABLE	UINT8_C(1)

+

+/** Buffer length macro declaration */

+#define BME680_TMP_BUFFER_LENGTH	UINT8_C(40)

+#define BME680_REG_BUFFER_LENGTH	UINT8_C(6)

+#define BME680_FIELD_DATA_LENGTH	UINT8_C(3)

+#define BME680_GAS_REG_BUF_LENGTH	UINT8_C(20)

+

+/** Settings selector */

+#define BME680_OST_SEL			UINT16_C(1)

+#define BME680_OSP_SEL			UINT16_C(2)

+#define BME680_OSH_SEL			UINT16_C(4)

+#define BME680_GAS_MEAS_SEL		UINT16_C(8)

+#define BME680_FILTER_SEL		UINT16_C(16)

+#define BME680_HCNTRL_SEL		UINT16_C(32)

+#define BME680_RUN_GAS_SEL		UINT16_C(64)

+#define BME680_NBCONV_SEL		UINT16_C(128)

+#define BME680_GAS_SENSOR_SEL		(BME680_GAS_MEAS_SEL | BME680_RUN_GAS_SEL | BME680_NBCONV_SEL)

+

+/** Number of conversion settings*/

+#define BME680_NBCONV_MIN		UINT8_C(0)

+#define BME680_NBCONV_MAX		UINT8_C(10)

+

+/** Mask definitions */

+#define BME680_GAS_MEAS_MSK	UINT8_C(0x30)

+#define BME680_NBCONV_MSK	UINT8_C(0X0F)

+#define BME680_FILTER_MSK	UINT8_C(0X1C)

+#define BME680_OST_MSK		UINT8_C(0XE0)

+#define BME680_OSP_MSK		UINT8_C(0X1C)

+#define BME680_OSH_MSK		UINT8_C(0X07)

+#define BME680_HCTRL_MSK	UINT8_C(0x08)

+#define BME680_RUN_GAS_MSK	UINT8_C(0x10)

+#define BME680_MODE_MSK		UINT8_C(0x03)

+#define BME680_RHRANGE_MSK	UINT8_C(0x30)

+#define BME680_RSERROR_MSK	UINT8_C(0xf0)

+#define BME680_NEW_DATA_MSK	UINT8_C(0x80)

+#define BME680_GAS_INDEX_MSK	UINT8_C(0x0f)

+#define BME680_GAS_RANGE_MSK	UINT8_C(0x0f)

+#define BME680_GASM_VALID_MSK	UINT8_C(0x20)

+#define BME680_HEAT_STAB_MSK	UINT8_C(0x10)

+#define BME680_MEM_PAGE_MSK	UINT8_C(0x10)

+#define BME680_SPI_RD_MSK	UINT8_C(0x80)

+#define BME680_SPI_WR_MSK	UINT8_C(0x7f)

+#define	BME680_BIT_H1_DATA_MSK	UINT8_C(0x0F)

+

+/** Bit position definitions for sensor settings */

+#define BME680_GAS_MEAS_POS	UINT8_C(4)

+#define BME680_FILTER_POS	UINT8_C(2)

+#define BME680_OST_POS		UINT8_C(5)

+#define BME680_OSP_POS		UINT8_C(2)

+#define BME680_RUN_GAS_POS	UINT8_C(4)

+

+/** Array Index to Field data mapping for Calibration Data*/

+#define BME680_T2_LSB_REG	(1)

+#define BME680_T2_MSB_REG	(2)

+#define BME680_T3_REG		(3)

+#define BME680_P1_LSB_REG	(5)

+#define BME680_P1_MSB_REG	(6)

+#define BME680_P2_LSB_REG	(7)

+#define BME680_P2_MSB_REG	(8)

+#define BME680_P3_REG		(9)

+#define BME680_P4_LSB_REG	(11)

+#define BME680_P4_MSB_REG	(12)

+#define BME680_P5_LSB_REG	(13)

+#define BME680_P5_MSB_REG	(14)

+#define BME680_P7_REG		(15)

+#define BME680_P6_REG		(16)

+#define BME680_P8_LSB_REG	(19)

+#define BME680_P8_MSB_REG	(20)

+#define BME680_P9_LSB_REG	(21)

+#define BME680_P9_MSB_REG	(22)

+#define BME680_P10_REG		(23)

+#define BME680_H2_MSB_REG	(25)

+#define BME680_H2_LSB_REG	(26)

+#define BME680_H1_LSB_REG	(26)

+#define BME680_H1_MSB_REG	(27)

+#define BME680_H3_REG		(28)

+#define BME680_H4_REG		(29)

+#define BME680_H5_REG		(30)

+#define BME680_H6_REG		(31)

+#define BME680_H7_REG		(32)

+#define BME680_T1_LSB_REG	(33)

+#define BME680_T1_MSB_REG	(34)

+#define BME680_GH2_LSB_REG	(35)

+#define BME680_GH2_MSB_REG	(36)

+#define BME680_GH1_REG		(37)

+#define BME680_GH3_REG		(38)

+

+/** BME680 register buffer index settings*/

+#define BME680_REG_FILTER_INDEX		UINT8_C(5)

+#define BME680_REG_TEMP_INDEX		UINT8_C(4)

+#define BME680_REG_PRES_INDEX		UINT8_C(4)

+#define BME680_REG_HUM_INDEX		UINT8_C(2)

+#define BME680_REG_NBCONV_INDEX		UINT8_C(1)

+#define BME680_REG_RUN_GAS_INDEX	UINT8_C(1)

+#define BME680_REG_HCTRL_INDEX		UINT8_C(0)

+

+/** BME680 pressure calculation macros */

+/*! This max value is used to provide precedence to multiplication or division

+ * in pressure compensation equation to achieve least loss of precision and

+ * avoiding overflows.

+ * i.e Comparing value, BME680_MAX_OVERFLOW_VAL = INT32_C(1 << 30)

+ */

+#define BME680_MAX_OVERFLOW_VAL      INT32_C(0x40000000)

+

+/** Macro to combine two 8 bit data's to form a 16 bit data */

+#define BME680_CONCAT_BYTES(msb, lsb)	(((uint16_t)msb << 8) | (uint16_t)lsb)

+

+/** Macro to SET and GET BITS of a register */

+#define BME680_SET_BITS(reg_data, bitname, data) \

+		((reg_data & ~(bitname##_MSK)) | \

+		((data << bitname##_POS) & bitname##_MSK))

+#define BME680_GET_BITS(reg_data, bitname)	((reg_data & (bitname##_MSK)) >> \

+	(bitname##_POS))

+

+/** Macro variant to handle the bitname position if it is zero */

+#define BME680_SET_BITS_POS_0(reg_data, bitname, data) \

+				((reg_data & ~(bitname##_MSK)) | \

+				(data & bitname##_MSK))

+#define BME680_GET_BITS_POS_0(reg_data, bitname)  (reg_data & (bitname##_MSK))

+

+/** Type definitions */

+/*!

+ * Generic communication function pointer

+ * @param[in] dev_id: Place holder to store the id of the device structure

+ *                    Can be used to store the index of the Chip select or

+ *                    I2C address of the device.

+ * @param[in] reg_addr:	Used to select the register the where data needs to

+ *                      be read from or written to.

+ * @param[in/out] reg_data: Data array to read/write

+ * @param[in] len: Length of the data array

+ */

+typedef int8_t (*bme680_com_fptr_t)(uint8_t dev_id, uint8_t reg_addr, uint8_t *data, uint16_t len);

+

+/*!

+ * Delay function pointer

+ * @param[in] period: Time period in milliseconds

+ */

+typedef void (*bme680_delay_fptr_t)(uint32_t period);

+

+/*!

+ * @brief Interface selection Enumerations

+ */

+enum bme680_intf {

+	/*! SPI interface */

+	BME680_SPI_INTF,

+	/*! I2C interface */

+	BME680_I2C_INTF

+};

+

+/* structure definitions */

+/*!

+ * @brief Sensor field data structure

+ */

+struct	bme680_field_data {

+	/*! Contains new_data, gasm_valid & heat_stab */

+	uint8_t status;

+	/*! The index of the heater profile used */

+	uint8_t gas_index;

+	/*! Measurement index to track order */

+	uint8_t meas_index;

+

+#ifndef BME680_FLOAT_POINT_COMPENSATION

+	/*! Temperature in degree celsius x100 */

+	int16_t temperature;

+	/*! Pressure in Pascal */

+	uint32_t pressure;

+	/*! Humidity in % relative humidity x1000 */

+	uint32_t humidity;

+	/*! Gas resistance in Ohms */

+	uint32_t gas_resistance;

+#else

+	/*! Temperature in degree celsius */

+	float temperature;

+	/*! Pressure in Pascal */

+	float pressure;

+	/*! Humidity in % relative humidity x1000 */

+	float humidity;

+	/*! Gas resistance in Ohms */

+	float gas_resistance;

+

+#endif

+

+};

+

+/*!

+ * @brief Structure to hold the Calibration data

+ */

+struct	bme680_calib_data {

+	/*! Variable to store calibrated humidity data */

+	uint16_t par_h1;

+	/*! Variable to store calibrated humidity data */

+	uint16_t par_h2;

+	/*! Variable to store calibrated humidity data */

+	int8_t par_h3;

+	/*! Variable to store calibrated humidity data */

+	int8_t par_h4;

+	/*! Variable to store calibrated humidity data */

+	int8_t par_h5;

+	/*! Variable to store calibrated humidity data */

+	uint8_t par_h6;

+	/*! Variable to store calibrated humidity data */

+	int8_t par_h7;

+	/*! Variable to store calibrated gas data */

+	int8_t par_gh1;

+	/*! Variable to store calibrated gas data */

+	int16_t par_gh2;

+	/*! Variable to store calibrated gas data */

+	int8_t par_gh3;

+	/*! Variable to store calibrated temperature data */

+	uint16_t par_t1;

+	/*! Variable to store calibrated temperature data */

+	int16_t par_t2;

+	/*! Variable to store calibrated temperature data */

+	int8_t par_t3;

+	/*! Variable to store calibrated pressure data */

+	uint16_t par_p1;

+	/*! Variable to store calibrated pressure data */

+	int16_t par_p2;

+	/*! Variable to store calibrated pressure data */

+	int8_t par_p3;

+	/*! Variable to store calibrated pressure data */

+	int16_t par_p4;

+	/*! Variable to store calibrated pressure data */

+	int16_t par_p5;

+	/*! Variable to store calibrated pressure data */

+	int8_t par_p6;

+	/*! Variable to store calibrated pressure data */

+	int8_t par_p7;

+	/*! Variable to store calibrated pressure data */

+	int16_t par_p8;

+	/*! Variable to store calibrated pressure data */

+	int16_t par_p9;

+	/*! Variable to store calibrated pressure data */

+	uint8_t par_p10;

+

+#ifndef BME680_FLOAT_POINT_COMPENSATION

+	/*! Variable to store t_fine size */

+	int32_t t_fine;

+#else

+	/*! Variable to store t_fine size */

+	float t_fine;

+#endif

+	/*! Variable to store heater resistance range */

+	uint8_t res_heat_range;

+	/*! Variable to store heater resistance value */

+	int8_t res_heat_val;

+	/*! Variable to store error range */

+	int8_t range_sw_err;

+};

+

+/*!

+ * @brief BME680 sensor settings structure which comprises of ODR,

+ * over-sampling and filter settings.

+ */

+struct	bme680_tph_sett {

+	/*! Humidity oversampling */

+	uint8_t os_hum;

+	/*! Temperature oversampling */

+	uint8_t os_temp;

+	/*! Pressure oversampling */

+	uint8_t os_pres;

+	/*! Filter coefficient */

+	uint8_t filter;

+};

+

+/*!

+ * @brief BME680 gas sensor which comprises of gas settings

+ *  and status parameters

+ */

+struct	bme680_gas_sett {

+	/*! Variable to store nb conversion */

+	uint8_t nb_conv;

+	/*! Variable to store heater control */

+	uint8_t heatr_ctrl;

+	/*! Run gas enable value */

+	uint8_t run_gas;

+	/*! Heater temperature value */

+	uint16_t heatr_temp;

+	/*! Duration profile value */

+	uint16_t heatr_dur;

+};

+

+/*!

+ * @brief BME680 device structure

+ */

+struct	bme680_dev {

+	/*! Chip Id */

+	uint8_t chip_id;

+	/*! Device Id */

+	uint8_t dev_id;

+	/*! SPI/I2C interface */

+	enum bme680_intf intf;

+	/*! Memory page used */

+	uint8_t mem_page;

+	/*! Ambient temperature in Degree C */

+	int8_t amb_temp;

+	/*! Sensor calibration data */

+	struct bme680_calib_data calib;

+	/*! Sensor settings */

+	struct bme680_tph_sett tph_sett;

+	/*! Gas Sensor settings */

+	struct bme680_gas_sett gas_sett;

+	/*! Sensor power modes */

+	uint8_t power_mode;

+	/*! New sensor fields */

+	uint8_t new_fields;

+	/*! Store the info messages */

+	uint8_t info_msg;

+	/*! Bus read function pointer */

+	bme680_com_fptr_t read;

+	/*! Bus write function pointer */

+	bme680_com_fptr_t write;

+	/*! delay function pointer */

+	bme680_delay_fptr_t delay_ms;

+	/*! Communication function result */

+	int8_t com_rslt;

+};

+

+

+

+#endif /* BME680_DEFS_H_ */

+/** @}*/

+/** @}*/

diff --git a/include/driver/bme680_util.h b/include/driver/bme680_util.h
new file mode 100644
index 0000000..1341b49
--- /dev/null
+++ b/include/driver/bme680_util.h
@@ -0,0 +1,7 @@
+#include <stdint.h>
+
+void bme680_delay_ms(uint32_t const period);
+
+int8_t bme680_i2c_read(uint8_t dev_id, uint8_t reg_addr, uint8_t *reg_data, uint16_t len);
+
+int8_t bme680_i2c_write(uint8_t dev_id, uint8_t reg_addr, uint8_t *reg_data, uint16_t len);