1
0
mirror of https://github.com/RIOT-OS/RIOT.git synced 2024-12-29 04:50:03 +01:00
RIOT/drivers/include/bmx280.h

312 lines
9.4 KiB
C

/*
* Copyright (C) 2016 Kees Bakker, SODAQ
* 2017 Inria
* 2018 Freie Universität Berlin
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @defgroup drivers_bmx280 BMP280/BME280 temperature, pressure and humidity sensor
* @ingroup drivers_sensors
* @brief Device driver interface for the Bosch BMP280 and BME280 sensors
*
* BMP280 and BME280 measure temperature in centi °C and pressure in Pa. BME280
* can also measure relative humidity in %.
*
* For more information, see the datasheets:
* * [BMP280](https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BMP280-DS001.pdf)
* * [BME280](https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BME280-DS002.pdf)
*
* This driver provides @ref drivers_saul capabilities.
*
* ## Usage
*
* To include this driver to your application, simply add one of the following
* to the application's Makefile:
*
* ```make
* # BME280 connected via SPI
* USEMODULE += bme280_spi
* # BME280 connected via I2C
* USEMODULE += bme280_i2c
* # BMP280 via SPI
* USEMODULE += bmp280_spi
* # BMP280 via I2C
* USEMODULE += bmp280_i2c
*
* # When using I2C, specify the default I2C device to use,
* # and the BME280's address (see datasheet).
* # The values below are the defaults:
* CFLAGS += -DBMX280_PARAM_I2C_DEV=I2C_DEV\(0\)
* CFLAGS += -DBMX280_PARAM_I2C_ADDR=0x77
*
* # Using SPI, you can override the default configuration by specifying the
* # used SPI bus and the ship select pin:
* CFLAGS += -DBMX280_PARAM_SPI_DEV=SPI_DEV\(x\)
* CFLAGS += -DBMX280_PARAM_CS=GPIO_PIN\(y,z\)
* ```
*
* This way the default parameters in `drivers/bmx280/include/bmx280_params.h`
* are replaced by these new values.
*
* @{
* @file
* @brief Device driver interface for the BMP280 and BME280 sensors
*
* @details There are three sensor values that can be read: temperature,
* pressure and humidity. The BME280 device usually measures them
* all at once. It is possible to skip measuring either of the
* values by changing the oversampling settings. The driver is
* written in such a way that a measurement is only started from
* the function that reads the temperature. In other words, you
* always have to call bmx280_read_temperature, and then optionally
* you can call the other two.
*
* @author Kees Bakker <kees@sodaq.com>
* @author Alexandre Abadie <alexandre.abadie@inria.fr>
* @author Hauke Petersen <hauke.petersen@fu-berlin.de>
*/
#ifndef BMX280_H
#define BMX280_H
#include <stdint.h>
#include "saul.h"
#if defined(MODULE_BME280_SPI) || defined(MODULE_BMP280_SPI)
#define BMX280_USE_SPI
#include "periph/spi.h"
#else
#include "periph/i2c.h"
#endif
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief Select the number or raw data bytes depending on the device type
*/
#if defined(MODULE_BME280_SPI) || defined(MODULE_BME280_I2C)
#define BMX280_RAW_LEN (8U)
#else
#define BMX280_RAW_LEN (6U)
#endif
/**
* @brief Calibration struct for the BMX280 sensor
*
* This must be read from the device at startup.
*/
typedef struct {
uint16_t dig_T1; /**< T1 coefficient */
int16_t dig_T2; /**< T2 coefficient */
int16_t dig_T3; /**< T3 coefficient */
uint16_t dig_P1; /**< P1 coefficient */
int16_t dig_P2; /**< P2 coefficient */
int16_t dig_P3; /**< P3 coefficient */
int16_t dig_P4; /**< P4 coefficient */
int16_t dig_P5; /**< P5 coefficient */
int16_t dig_P6; /**< P6 coefficient */
int16_t dig_P7; /**< P7 coefficient */
int16_t dig_P8; /**< P8 coefficient */
int16_t dig_P9; /**< P9 coefficient */
uint8_t dig_H1; /**< H1 coefficient */
int16_t dig_H2; /**< H2 coefficient */
uint8_t dig_H3; /**< H3 coefficient */
int16_t dig_H4; /**< H4 coefficient */
int16_t dig_H5; /**< H5 coefficient */
int8_t dig_H6; /**< H6 coefficient */
} bmx280_calibration_t;
/**
* @brief Values for t_sb field of the BMX280 config register
*/
typedef enum {
BMX280_SB_0_5 = 0x00,
BMX280_SB_62_5 = 0x20,
BMX280_SB_125 = 0x40,
BMX280_SB_250 = 0x60,
BMX280_SB_500 = 0x80,
BMX280_SB_1000 = 0xa0,
BMX280_SB_10 = 0xc0,
BMX280_SB_20 = 0xe0,
} bmx280_t_sb_t;
/**
* @brief Values for filter field of the BMX280 config register
*/
typedef enum {
BMX280_FILTER_OFF = 0x00,
BMX280_FILTER_2 = 0x04,
BMX280_FILTER_4 = 0x08,
BMX280_FILTER_8 = 0x0c,
BMX280_FILTER_16 = 0x10,
} bmx280_filter_t;
/**
* @brief Values for mode field of the BMX280 ctrl_meas register
*/
typedef enum {
BMX280_MODE_SLEEP = 0x00,
BMX280_MODE_FORCED = 0x01,
BMX280_MODE_NORMAL = 0x03,
} bmx280_mode_t;
/**
* @brief Values for oversampling settings
*
* These values are used for:
* - osrs_h field of the BME280 ctrl_hum register
* - osrs_t field of the BMX280 ctrl_meas register
* - osrs_p field of the BMX280 ctrl_meas register
*/
typedef enum {
BMX280_OSRS_SKIPPED = 0x00,
BMX280_OSRS_X1 = 0x01,
BMX280_OSRS_X2 = 0x02,
BMX280_OSRS_X4 = 0x03,
BMX280_OSRS_X8 = 0x04,
BMX280_OSRS_X16 = 0x05,
} bmx280_osrs_t;
/**
* @brief Parameters for the BMX280 sensor
*
* These parameters are needed to configure the device at startup.
*/
typedef struct {
#ifdef BMX280_USE_SPI
/* SPI configuration */
spi_t spi; /**< SPI bus */
spi_clk_t clk; /**< clock speed for the SPI bus */
gpio_t cs; /**< chip select pin */
#else
/* I2C details */
i2c_t i2c_dev; /**< I2C device which is used */
uint8_t i2c_addr; /**< I2C address */
#endif
/* Config Register */
bmx280_t_sb_t t_sb; /**< standby */
bmx280_filter_t filter; /**< filter coefficient */
/* ctrl_meas */
bmx280_mode_t run_mode; /**< ctrl_meas mode */
bmx280_osrs_t temp_oversample; /**< ctrl_meas osrs_t */
bmx280_osrs_t press_oversample; /**< ctrl_meas osrs_p */
/* ctrl_hum */
bmx280_osrs_t humid_oversample; /**< ctrl_hum osrs_h */
} bmx280_params_t;
/**
* @brief Device descriptor for the BMX280 sensor
*/
typedef struct {
bmx280_params_t params; /**< Device Parameters */
bmx280_calibration_t calibration; /**< Calibration Data */
int32_t t_fine; /**< temperature compensation value */
uint8_t last_reading[BMX280_RAW_LEN]; /**< cache the RAW data */
} bmx280_t;
/**
* @brief Status and error return codes
*/
enum {
BMX280_OK = 0, /**< everything was fine */
BMX280_ERR_BUS = -1, /**< bus error */
BMX280_ERR_NODEV = -2, /**< did not detect BME280 or BMP280 */
};
/**
* @brief Export of SAUL interface for temperature sensor
*/
extern const saul_driver_t bmx280_temperature_saul_driver;
/**
* @brief Export of SAUL interface for pressure sensor
*/
extern const saul_driver_t bmx280_pressure_saul_driver;
#if defined(MODULE_BME280_SPI) || defined(MODULE_BME280_I2C)
/**
* @brief Export of SAUL interface for humidity sensor
*/
extern const saul_driver_t bme280_relative_humidity_saul_driver;
#endif
/**
* @brief Initialize the given BMX280 device
*
* @param[out] dev device descriptor of the given BMX280 device
* @param[in] params static configuration parameters
*
* @return BMX280_OK on success
* @return BMX280_ERR_BUS on bus error
* @return BMX280_ERR_NODEV if no corresponding device was found on the bus
*/
int bmx280_init(bmx280_t* dev, const bmx280_params_t* params);
/**
* @brief Read temperature value from the given BMX280 device
*
* The measured temperature is returned in centi °C (x.xx°C).
*
* @param[in] dev device to read from
*
* @return measured temperature in centi Celsius
* @return INT16_MIN on error
*/
int16_t bmx280_read_temperature(bmx280_t* dev);
/**
* @brief Read air pressure value from the given BMX280 device
*
* The air pressure is returned in PA (Pascal).
*
* This function returns the pressure data that was measured when
* bmx280_read_temperature() has been called last. So bmx280_read_temperature()
* has to be called before.
*
* If bmx280_read_temperatue() did not succeed in acquiring a new set of sensor
* data, the result of this function is undefined.
*
* @param[in] dev device to read from
*
* @return air pressure in PA
*/
uint32_t bmx280_read_pressure(bmx280_t *dev);
#if defined(MODULE_BME280_SPI) || defined(MODULE_BME280_I2C) || defined(DOXYGEN)
/**
* @brief Read humidity value from the given BME280 device
*
* The humidity is returned in centi %RH (x.xx% relative humidity).
*
* This function returns the pressure data that was measured when
* bmx280_read_temperature() has been called last. So bmx280_read_temperature()
* has to be called before.
*
* If bmx280_read_temperatue() did not succeed in acquiring a new set of sensor
* data, the result of this function is undefined.
*
* @param[in] dev device to read from
*
* @return humidity in centi %RH (i.e. the percentage times 100)
*/
uint16_t bme280_read_humidity(bmx280_t *dev);
#endif
#ifdef __cplusplus
}
#endif
#endif /* BMX280_H */
/** @} */