IMU API

Infuse IMU API . More...

Data Structures
struct	imu_config
	IMU configuration struct. More...
struct	imu_config_output
	Configured IMU value. More...
struct	imu_sample
struct	imu_sensor_meta
	Metadata for each sub-sensor in a FIFO buffer. More...
struct	imu_sample_array
	FIFO read structure. More...
struct	infuse_imu_api
struct	imu_linear_downsample_scaled_state
	State for imu_linear_downsample_scaled. More...

Macros
#define	IMU_SAMPLE_ARRAY_TYPE_DEFINE(type_name, max_samples)
	Create type that holds a given number of IMU samples.
#define	IMU_SAMPLE_ARRAY_CREATE(name, max_samples)
	Create static buffer of IMU samples suitable for use with imu_data_read.

Functions
static int	imu_configure (const struct device *dev, const struct imu_config *config, struct imu_config_output *output)
	Configure IMU for operation.
static int	imu_data_wait (const struct device *dev, k_timeout_t timeout)
	Wait for FIFO interrupt from IMU.
static int	imu_data_read (const struct device *dev, struct imu_sample_array *samples, uint16_t max_samples)
	Read samples from IMU.
static int	imu_self_test (const struct device *dev)
	Run self-test functionality on the IMU.
static int16_t	imu_accelerometer_1g (uint8_t full_scale)
	Convert a full scale range to an expected value for 1G.
static uint32_t	imu_sample_period (const struct imu_sensor_meta *meta)
	Get the local ticks between samples in a buffer.
static uint16_t	imu_sample_rate (const struct imu_sensor_meta *meta)
	Get the approximate sample rate of a buffer.
static k_ticks_t	imu_sample_timestamp (const struct imu_sensor_meta *meta, uint8_t sample)
	Get the local tick counter of a given sample in a buffer.
int	imu_linear_downsample_scaled (struct imu_linear_downsample_scaled_state *state, const struct imu_sample *input, uint16_t num_input)
	Downsample IMU samples to a new frequency using linear interpolation.

Detailed Description

Infuse IMU API .

Macro Definition Documentation

IMU_SAMPLE_ARRAY_CREATE

#define IMU_SAMPLE_ARRAY_CREATE	(		name,
			max_samples )

#include <infuse/drivers/imu.h>

Value:

        IMU_SAMPLE_ARRAY_TYPE_DEFINE(_anon_t_##name, max_samples);                                 \
        static struct _anon_t_##name _anon_##name;                                                 \
        static struct imu_sample_array *name = (void *)&_anon_##name

Create static buffer of IMU samples suitable for use with imu_data_read.

IMU_SAMPLE_ARRAY_TYPE_DEFINE

#define IMU_SAMPLE_ARRAY_TYPE_DEFINE	(		type_name,
			max_samples )

#include <infuse/drivers/imu.h>

Value:

        struct type_name {                                                                         \
                struct imu_sample_array header;                                                    \
                struct imu_sample samples[max_samples];                                            \
        }

Create type that holds a given number of IMU samples.

Function Documentation

imu_accelerometer_1g()

static int16_t imu_accelerometer_1g ( uint8_t full_scale )

inlinestatic

#include <infuse/drivers/imu.h>

Convert a full scale range to an expected value for 1G.

Parameters

full_scale

Full scale range in G's (e.g 4 for +- 4G)

Returns

int16_t value expected for 1G

imu_configure()

static int imu_configure ( const struct device * dev, const struct imu_config * config, struct imu_config_output * output )

inlinestatic

#include <infuse/drivers/imu.h>

Configure IMU for operation.

Parameters

dev	IMU to configure
config	Desired sensor configuration, or NULL to disable
output	Configured sensor timings

Return values

0	on success
-EINVAL	on invalid parameters
-errno	on error

imu_data_read()

static int imu_data_read ( const struct device * dev, struct imu_sample_array * samples, uint16_t max_samples )

inlinestatic

#include <infuse/drivers/imu.h>

Read samples from IMU.

Parameters

dev	IMU to read from
samples	Sample buffer to read into
max_samples	Maximum number of samples to populate

Return values

0	on success
1	on success, but FIFO frames have been lost
-ENOMEM	more than max_samples samples buffered
-errno	on error

imu_data_wait()

static int imu_data_wait ( const struct device * dev, k_timeout_t timeout )

inlinestatic

#include <infuse/drivers/imu.h>

Wait for FIFO interrupt from IMU.

Parameters

dev	IMU to wait on
timeout	Duration to wait for

Return values

0	on success
-EAGAIN	on timeout

imu_linear_downsample_scaled()

int imu_linear_downsample_scaled	(	struct imu_linear_downsample_scaled_state *	state,
		const struct imu_sample *	input,
		uint16_t	num_input )

#include <infuse/drivers/imu.h>

Downsample IMU samples to a new frequency using linear interpolation.

Function returns as soon as state.output_offset == state.output_size. Function should be called again with remaining samples once output buffer has been processed and state.output_offset reset to 0.

output_frequency = input_frequency * freq_mult / freq_div

Parameters

state	State structure
input	Input IMU sample buffer
num_input	Number of samples in input

Return values

number

of input samples consumed

imu_sample_period()

static uint32_t imu_sample_period ( const struct imu_sensor_meta * meta )

inlinestatic

#include <infuse/drivers/imu.h>

Get the local ticks between samples in a buffer.

Parameters

meta	Metadata for the relevant channel in a buffer

Returns

uint32_t Ticks between samples in the buffer

imu_sample_rate()

static uint16_t imu_sample_rate ( const struct imu_sensor_meta * meta )

inlinestatic

#include <infuse/drivers/imu.h>

Get the approximate sample rate of a buffer.

Parameters

meta	Metadata for the relevant channel in a buffer

Returns

uint16_t Approximate sample rate in Hertz

imu_sample_timestamp()

static k_ticks_t imu_sample_timestamp ( const struct imu_sensor_meta * meta, uint8_t sample )

inlinestatic

#include <infuse/drivers/imu.h>

Get the local tick counter of a given sample in a buffer.

Parameters

meta	Metadata for the relevant channel in a buffer
sample	Sample index to get timestamp for

Returns

k_ticks_t Timestamp for sample N in the buffer

imu_self_test()

static int imu_self_test ( const struct device * dev )

inlinestatic

#include <infuse/drivers/imu.h>

Run self-test functionality on the IMU.

Parameters

dev	IMU to run self-test on

Return values

0	on success
-errno	on error