/*

• Copyright (C) 2016-2017 STMicroelectronics

• Author: Denis Ciocca denis.ciocca@st.com

• Licensed under the Apache License, Version 2.0 (the "License");

• you may not use this file except in compliance with the License.

• You may obtain a copy of the License at

• http://www.apache.org/licenses/LICENSE-2.0

• Unless required by applicable law or agreed to in writing, software

• distributed under the License is distributed on an "AS IS" BASIS,

• WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

• See the License for the specific language governing permissions and

• limitations under the License. */

  <---------- Introduction ---------->

In order to build the driver for a platform some macros (see Macros list) must be defined into variant.h file. [variant/{VARIANT_NAME}/inc/variant/variant.h] Those macros define specific configuration that is platform dependent (SPI bus, SPI frequency, etc).

Optional FLAGS (FLAGS list) can be used to enable specific features using variant makefile. [variant/{VARIANT_NAME}/{VARIANT_NAME}.mk] Those flags modify @ compile time the behavior of the driver enabling for example i2c master support or calibration libraries.

<---------- Macros list ---------->

#define LSM6DSM_SPI_SLAVE_BUS_ID 1 /* SPI bus ID, on STM32F4xx indicate SPI2 / #define LSM6DSM_SPI_SLAVE_FREQUENCY_HZ 8000000 / SPI frequency in Hz / #define LSM6DSM_SPI_SLAVE_CS_GPIO GPIO_PB(12) / SPI NSS pin, on STM32F4xx indicate NSS of SPI2 */

#define LSM6DSM_INT_IRQ EXTI2_IRQn #define LSM6DSM_INT1_GPIO GPIO_PB(6) /* LSM6DSM INT1 is required, here connected to STM32F4xx PB6 */

#define LSM6DSM_ACCEL_GYRO_ROT_MATRIX 1, 0, 0, 0, 1, 0, 0, 0, 1 /* Accelerometer and gyroscope axis orientation / #define LSM6DSM_MAGN_ROT_MATRIX 1, 0, 0, 0, 1, 0, 0, 0, 1 / Magnetometer axis orientation [MUST be set if a magn sensor is enabled] */

#define LSM6DSM_LIS3MDL_I2C_ADDRESS 0x1e /* STM LIS3MDL I2C address / #define LSM6DSM_LPS22HB_I2C_ADDRESS 0x5d / STM LPS22HB I2C address */

<---------- FLAGS list ---------->

• LSM6DSM_DBG_ENABLED /* Enable debug messages */

• LSM6DSM_ACCEL_CALIB_ENABLED /* Enable accelerometer bias calibration */

• LSM6DSM_GYRO_CALIB_ENABLED /* Enable gyroscope bias calibration */

• LSM6DSM_OVERTEMP_CALIB_ENABLED /* Enable gyroscope over temperature bias calibration [Require LSM6DSM_GYRO_CALIB_ENABLED] */

• LSM6DSM_MAGN_CALIB_ENABLED /* Enable magnetometer offset calibration */

• LSM6DSM_I2C_MASTER_USE_INTERNAL_PULLUP /* Use internal pull-up resistors for I2C master interface */

/* Magnetometer sensor (only one per time can be used) */

• LSM6DSM_I2C_MASTER_LIS3MDL /* Enable STM LIS3MDL magn sensor */
• LSM6DSM_I2C_MASTER_LSM303AGR /* Enable STM LSM303AGR magn sensor */
• LSM6DSM_I2C_MASTER_AK09916 /* Enable AKM AK09916 magn sensor */

/* Barometer sensor (only one per time can be used) */

• LSM6DSM_I2C_MASTER_LPS22HB /* Enable STM LPS22HB pressure sensor */

Example: variant/nucleo/nucleo.mk

FLAGS += -DLSM6DSM_DBG_ENABLED -DLSM6DSM_ACCEL_CALIB_ENABLED -DLSM6DSM_GYRO_CALIB_ENABLED -DLSM6DSM_OVERTEMP_CALIB_ENABLED FLAGS += -DLSM6DSM_I2C_MASTER_LSM303AGR -DLSM6DSM_I2C_MASTER_USE_INTERNAL_PULLUP -DLSM6DSM_MAGN_CALIB_ENABLED

<---------- ROT_MATRIX macro explanation ---------->

Sensors orientation can be modified through rotation matrices. Accelerometer and gyroscope are sharing same configuration (LSM6DSM_ACCEL_GYRO_ROT_MATRIX), magnetometer sensor different one (LSM6DSM_MAGN_ROT_MATRIX). It is following standard rule of matrices moltiplications. Here an example:

                   [r11 r12 r13]

[x" y" z"] = [x y z] * [r21 r22 r23] = [(xr11 + yr21 + zr31) (xr12 + yr22 + zr32) (xr13 + yr23 + z*r33)] [r31 r32 r33]

where x,y,z are sensors output and x",y",z" are android coordinate system data. Matrix is so defined: #define LSM6DSM_ACCEL_GYRO_ROT_MATRIX r11,r12,r13,r21,r22,r23,r31,r32,r33

r** can only be: 0 or 1 or -1.

<---------- Supported features ---------->

Accel & Gyro data; Accel bias calibration through accel_cal lib; Gyro bias calibration through gyro_cal & gyro_stillnes_detect libs; Step detector & counter; Significant motion; Magnetometer sensor connected through I2C master interface (LIS3MDL, LSM303AGR, AK09916); Magnetometer calibration though mag_cal lib; Pressure sensor connected through I2C master interface (LPS22HB);