BMI270 API Reference Guide

General Description

Basic set of API for interacting with the BMI270 motion sensor.

This provides basic initialization and access to the basic accelerometer and gyroscope data. It also provides access to the base BMI270 driver for full control. For more information about the sensor, see: https://github.com/boschsensortec/BMI270_SensorAPI/tree/v2.86.1

Code Snippets

Snippet 1: Simple initialization with I2C

The following snippet initializes an I2C instance and the BMI270, then does configuration of BMI270.

/* Initialize I2C and BMI270 */
result = cyhal_i2c_init(&i2c_instance, CYBSP_I2C_SDA, CYBSP_I2C_SCL, NULL);
result = mtb_bmi270_init_i2c(&imu, &i2c_instance, MTB_BMI270_ADDRESS_DEFAULT);
/* Default configuration for BMI270 */
result = mtb_bmi270_config_default(&imu);

Snippet 2: Read accelerometer and gyroscope data

The following snippet demonstrates how to read accelerometer and gyroscope from BMI270.

/* Read data from BMI270 */
mtb_bmi270_data_t data;
result = mtb_bmi270_read(&imu, &data);

Data Structure

struct mtb_bmi270_t         Structure holding the IMU instance specific information
struct mtb_bmi270_data_t    Structure holding the accelerometer and gyroscope data read from the device

Enumerations

Enumeration used for selecting I2C address.

typedef enum
{
   MTB_BMI270_ADDRESS_DEFAULT  = BMI2_I2C_PRIM_ADDR,
   MTB_BMX270_ADDRESS_SEC      = BMI2_I2C_SEC_ADDR
} mtb_bmi270_address_t;

Functions

cy_rslt_t mtb_bmi270_init_i2c(mtb_bmi270_t* dev, cyhal_i2c_t* i2c_instance, mtb_bmi270_address_t dev_addr)

Initializes the sensor with I2C interface.

cy_rslt_t mtb_bmi270_config_default(mtb_bmi270_t* dev)

Configures the motion sensor to a default mode with both accelerometer and gyroscope enabled with a nominal output data rate.

cy_rslt_t mtb_bmi270_read(mtb_bmi270_t* dev, mtb_bmi270_data_t* data)

Reads the current accelerometer and gyroscope data from the motion sensor.

cy_rslt_t mtb_bmi270_selftest(mtb_bmi270_t* dev)

Performs both accelerometer and gyro self tests.

cy_rslt_t mtb_bmi270_config_int(mtb_bmi270_t* dev, struct bmi2_int_pin_config* intsettings, cyhal_gpio_t pin, uint8_t intr_priority, cyhal_gpio_event_t event, cyhal_gpio_event_callback_t callback, void* callback_arg)

This configures the pin as an interrupt, and calls the BMI270 interrupt configuration API with the application supplied settings structure.

void mtb_bmi270_free_pin(mtb_bmi270_t* dev)

Frees up any resources allocated by the sensor as part of mtb_bmi270_init_i2c().

Data Structure Documentation

mtb_bmi270_t

Data Fields	object	Description
bmi2_dev	sensor	Structure to define BMI270 sensor configurations
_mtb_bmi270_interrupt_pin_t	intpin1	Internal structure containing callback data for pins
_mtb_bmi270_interrupt_pin_t	intpin2	Internal structure containing callback data for pins

mtb_bmi270_data_t

Data Fields	object	Description
bmi2_sens_data	sensor_data	Accelerometer and Gyroscope data

Function Documentation

mtb_bmi270_init_i2c

cy_rslt_t mtb_bmi270_init_i2c(mtb_bmi270_t* dev, cyhal_i2c_t* i2c_instance, mtb_bmi270_address_t dev_addr);

Summary: This function initializes the I2C instance, configures the BMI270, and sets platform-dependent function pointers.

Parameter:

Parameters Description

dev Pointer to a BMI270 object. The caller must allocate the memory for this object but the init function will initialize its contents.

i2c_instance I2C instance to use for communicating with the BMI270 sensor.

dev_addr BMI270 I2C address, set by hardware implementation.

Return:

cy_rslt_t : CY_RSLT_SUCCESS if properly initialized, else an error indicating what went wrong.

Parameters	Description
dev	Pointer to a BMI270 object. The caller must allocate the memory for this object but the init function will initialize its contents.
i2c_instance	I2C instance to use for communicating with the BMI270 sensor.
dev_addr	BMI270 I2C address, set by hardware implementation.

mtb_bmi270_config_default

cy_rslt_t mtb_bmi270_config_default(mtb_bmi270_t* dev)

Summary: Configures the motion sensor to a default mode with both accelerometer and gyroscope enabled with a nominal output data rate.

The default values used are from the example in the BMI270 driver repository.

Parameter:

Parameters Description

dev Pointer to a BMI270 object. The caller must allocate the memory for this object but the init function will initialize its contents.

Return:

cy_rslt_t : CY_RSLT_SUCCESS if properly configured, else an error indicating what went wrong.

Parameters	Description
dev	Pointer to a BMI270 object. The caller must allocate the memory for this object but the init function will initialize its contents.

mtb_bmi270_read

cy_rslt_t mtb_bmi270_read(mtb_bmi270_t* dev, mtb_bmi270_data_t* data)

Summary: Reads the current accelerometer and gyroscope data from the motion sensor.

Parameter:

Parameters Description

dev Pointer to a BMI270 object. The caller must allocate the memory for this object but the init function will initialize its contents.

data The accelerometer and gyroscope data read from the motion sensor

Return:

cy_rslt_t : CY_RSLT_SUCCESS if properly read, else an error indicating what went wrong.

Parameters	Description
dev	Pointer to a BMI270 object. The caller must allocate the memory for this object but the init function will initialize its contents.
data	The accelerometer and gyroscope data read from the motion sensor

mtb_bmi270_selftest

cy_rslt_t mtb_bmi270_selftest(mtb_bmi270_t* dev)

Summary: Performs both accelerometer and gyro self tests.

Note these tests cause a soft reset of the device and device should be reconfigured after a test.

Parameter:

Parameters Description

dev Pointer to a BMI270 object. The caller must allocate the memory for this object but the init function will initialize its contents.

Return:

cy_rslt_t : CY_RSLT_SUCCESS if test passed, else an error indicating what went wrong.

Parameters	Description
dev	Pointer to a BMI270 object. The caller must allocate the memory for this object but the init function will initialize its contents.

mtb_bmi270_config_int

cy_rslt_t mtb_bmi270_config_int(mtb_bmi270_t* dev, struct bmi2_int_pin_config* intsettings, cyhal_gpio_t pin, uint8_t intr_priority, cyhal_gpio_event_t event, cyhal_gpio_event_callback_t callback, void* callback_arg)

Summary: This configures the pin as an interrupt, and calls the BMI270 interrupt configuration API with the application supplied settings structure.

Note: To get the current interrupt configuration, bmi2_get_int_pin_config should be called in the application.

Parameter:

Parameters Description

dev Pointer to a BMI270 object. The caller must allocate the memory for this object but the init function will initialize its contents.

intsettings Pointer to a BMI270 interrupt settings structure.

pin Which pin to configure as interrupt.

intr_priority The priority for NVIC interrupt events.

event The type of interrupt event.

callback The function to call when the specified event happens. Pass NULL to unregister the handler.

callback_arg Generic argument that will be provided to the callback when called, can be NULL.

Return:

cy_rslt_t : CY_RSLT_SUCCESS if properly configured, else an error indicating what went wrong.

Parameters	Description
dev	Pointer to a BMI270 object. The caller must allocate the memory for this object but the init function will initialize its contents.
intsettings	Pointer to a BMI270 interrupt settings structure.
pin	Which pin to configure as interrupt.
intr_priority	The priority for NVIC interrupt events.
event	The type of interrupt event.
callback	The function to call when the specified event happens. Pass NULL to unregister the handler.
callback_arg	Generic argument that will be provided to the callback when called, can be NULL.

mtb_bmi270_free_pin

void mtb_bmi270_free_pin(mtb_bmi270_t* dev)

Summary: Frees up any resources allocated by the motion sensor as part of mtb_bmi270_init_i2c().

Parameter:

Parameters Description

dev Pointer to a BMI270 object. The caller must allocate the memory for this object but the init function will initialize its contents.

sensor-motion-bmi270/api_reference.md