OIS_README.md

Sensor API for the BMI2's OIS interface

Table of Contents

• Introduction
• Integration details
• Driver files information
• Sensor interfaces
• Integration Examples

Introduction

This package contains Bosch Sensortec's BMI2 Sensor API.

Integration details

• Integrate bmi2.c, bmi2.h, bmi2_ois.c, bmi2_ois.h, bmi2_defs.h and the required variant files in your project.
• User has to include bmi2_ois.h in the code to call OIS related APIs and a variant header for initialization as well as BMI2 related API calls, as shown below:

#include "bmi261.h"
#include "bmi2_ois.h"

Driver files information

• bmi2_ois.c
  • This file has function definitions of OIS related API interfaces.
• bmi2_ois.h
  • This header file has necessary include files, function declarations, required to make OIS related API calls.

Sensor interfaces

Host Interface

• I2C interface
• SPI interface
  Note: By default, the interface is I2C.

OIS Interface

• SPI interface

Integration examples

Configuring SPI/I2C for host interface.

To configure host interface, an instance of the bmi2_dev structure should be created for initializing BMI2 sensor. "Refer README for initializing BMI2 sensor."

Configuring SPI for OIS interface.

To configure OIS interface, an instance of the bmi2_ois_dev structure should be created. The following parameters are required to be updated in the structure, by the user.

Parameters	Details
intf_ptr	device address reference of SPI interface
ois_read	read through SPI interface
ois_write	read through SPI interface
ois_delay_us	delay in micro seconds
acc_en	for enabling accelerometer
gyr_en	for enabling gyroscope

int8_t rslt = 0;

struct bmi2_ois_dev ois_dev = {  
        .intf_ptr = intf_ptr will contain the chip selection info of SPI CS pin,  
        .ois_read = user_spi_reg_read,
        .ois_write = user_spi_reg_write,
        .ois_delay_us = user_delay_us
};

Important Note: For initializing and configuring BMI2 sensors, which is done through host interface, the API's are to be used from bmi2.c file. Rest of the API's, for OIS configurations and the reading of OIS data, which is done through OIS interface, are to be used from bmi2_ois.c file.

Get accelerometer and gyroscope data through OIS interface

int8_t rslt;
/* Array to enable sensor through host interface */
uint8_t sens_list[2] = {BMI2_ACCEL, BMI2_GYRO};
/* Array to enable sensor through OIS interface */
uint8_t sens_sel[2] = {BMI2_OIS_ACCEL, BMI2_OIS_GYRO};
/* Initialize the configuration structure */
struct bmi2_sens_config sens_cfg = {0};

/* Initialize BMI2 */
rslt = bmi2_init(&dev);
if (rslt != BMI2_OK) {
        printf("Error: %d\n", rslt);
        return;
}

/* Enable accelerometer and gyroscope through host interface */
rslt = bmi2_sensor_enable(sens_list, 2, &dev);
if (rslt != BMI2_OK) {
        printf("Error: %d\n", rslt);
        return;
}

/* Setting of OIS Range is done through host interface */
/* Select the gyroscope sensor for OIS Range configuration */
sens_cfg.type = BMI2_GYRO;

/* Get gyroscope configuration */
rslt = bmi2_get_sensor_config(&sens_cfg, 1, &dev);
if (rslt != BMI2_OK) {
        printf("Error: %d\n", rslt);
        return;
}

/* Set the desired OIS Range */
sens_cfg.cfg.gyr.ois_range = BMI2_GYR_OIS_2000;

/* Set gyroscope configuration for default values */
rslt = bmi2_set_sensor_config(&sens_cfg, 1, &dev);
if (rslt != BMI2_OK) {
         printf("Error: %d\n", rslt);
         return;
}

/* Enable OIS through host interface */
rslt = bmi2_set_ois_interface(BMI2_ENABLE, &dev);
if (rslt != BMI2_OK) {
         printf("Error: %d\n", rslt);
         return;
}

/* Disable Advance Power Save Mode through host interface */
rslt = bmi2_set_adv_power_save(BMI2_DISABLE, &dev);
if (rslt != BMI2_OK) {
         printf("Error: %d\n", rslt);
         return;
}

/* Get configurations for OIS through OIS interface for default values */
rslt = bmi2_ois_get_config(&ois_dev);
if (rslt != BMI2_OK) {
         printf("Error: %d\n", rslt);
         return;
}

/* Enable accelerometer and gyroscope for reading OIS data */
ois_dev.acc_en = BMI2_ENABLE;
ois_dev.gyr_en = BMI2_ENABLE;

/* Set configurations for OIS through OIS interface */
rslt = bmi2_ois_set_config(&ois_dev);
if (rslt == BMI2_OK) {
        /* Get OIS accelerometer and gyroscope data through OIS interface */
        rslt = bmi2_ois_read_data(sens_sel, 2, &ois_dev);
        if (rslt == BMI2_OK) {
                /* Print accelerometer data */
                printf("OIS Accel x-axis = %d\t", ois_dev.acc_data.x);
                printf("OIS Accel y-axis= %d\t", ois_dev.acc_data.y);
                printf("OIS Accel z-axis = %d\r\n", ois_dev.acc_data.z);        
        
                /* Print gyroscope data */
                printf("OIS Gyro x-axis = %d\t", ois_dev.gyr_data.x);
                printf("OIS Gyro y-axis= %d\t", ois_dev.gyr_data.y);
                printf("OIS Gyro z-axis = %d\r\n", ois_dev.gyr_data.z);
        }        
}

if (rslt != BMI2_OK) {
         printf("Error code: %d\n", rslt);
         return;
}

/* Enable Advance Power Save Mode through host interface */
rslt = bmi2_set_adv_power_save(BMI2_ENABLE, &dev);
if (rslt != BMI2_OK) {
        printf("Error: %d\n", rslt);
        return;
}