BMI270 Sensor API

The BMI270 API supports several functional modes depending on the specific implementation or hardware configuration used:

BMI270 (base)

Standard features include:

• Motion detection: Any motion, No motion, Significant motion.
• Pedometer: Wrist-worn Step counter and Step detector.
• Activity recognition: Still, Walking, Running.
• Wrist gestures: Push arm down, Pivot up, Wrist shake jiggle, Flick in, Flick out.
• Wrist wear wake up.

BMI270 Context

Focused features include:

• Pedometer: Step counter and Step detector.
• Activity recognition: Still, Walking, Running.

BMI270 Legacy

Includes older or specific detection capabilities:

• Motion detection: Any motion, No motion, Significant motion.
• Orientation detection: Advanced Portrait-Landscape.
• Fall/Impact detection: High-G, Low-G (Freefall), Flat detector.
• Tap detection: Single, Double, Triple taps.
• Smartphone Pedometer: Step counter and Step detector.
• Activity recognition: Still, Walking, Running.

BMI270 Maximum FIFO

• Supports a 6kB FIFO buffer.

To read OIS data, follow this workflow:

1. Initialize BMI2 via the host interface using bmi2_init().
2. Enable sensors (Accel/Gyro) via the host interface using bmi2_sensor_enable().
3. Configure OIS Range via the host interface using bmi2_get_sensor_config() and bmi2_set_sensor_config().
4. Enable OIS interface via the host interface using bmi2_set_ois_interface(BMI2_ENABLE, &dev).
5. Configure OIS via the OIS interface using bmi2_ois_get_config() and bmi2_ois_set_config(&ois_dev).
6. Read Data via the OIS interface using bmi2_ois_read_data().

Data is accessed through the ois_dev.acc_data and ois_dev.gyr_data structures.

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 */
sens_cfg.type = BMI2_GYRO;
rslt = bmi2_get_sensor_config(&sens_cfg, 1, &dev);
if (rslt != BMI2_OK) {
        printf("Error: %d\n", rslt);
        return;
}

sens_cfg.cfg.gyr.ois_range = BMI2_GYR_OIS_2000;
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 */
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);

To use the OIS interface, you must create and populate an instance of the struct bmi2_ois_dev. This structure requires the following parameters to be provided by the user:

Note: acc_en and gyr_en are used to enable the sensors for OIS data reading.

int8_t rslt = 0;

struct bmi2_ois_dev ois_dev = {  
        .intf_ptr = intf_ptr, // contains SPI CS pin info
        .ois_read = user_spi_reg_read,
        .ois_write = user_spi_reg_write,
        .ois_delay_us = user_delay_us
};