IMU interface and data handling implementation for VOXL OpenVINS. More...

#include "ImuMinimal.h"
#include <cstdio>
#include <state/State.h>

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Macros
#define	TS_PRINT(msg)

Functions
void	_imu_data_handler_cb (int ch, char data, int bytes, void context)
	Handler for incoming IMU data.

void	_imu_disconnect_cb (__attribute__((unused)) int ch, __attribute__((unused)) void *context)
	Callback for IMU disconnect events.

int	connect_imu_service (void)
	Creates IMU pipe client and associated callbacks.

Variables
std::mutex	imu_lock_mutex
	Mutex for IMU data access synchronization.

Detailed Description

IMU interface and data handling implementation for VOXL OpenVINS.

Author: Zauberflote

Date: 2025

Version: 1.0

This file implements the IMU interface and callback functions for handling inertial measurement unit data in the VOXL OpenVINS system. It provides the connection to the IMU service and data processing capabilities.

The implementation provides:

IMU data reception and validation
Frame transformation for different IMU orientations
Batch processing for efficient VIO integration
Camera-IMU synchronization
VIO state management and publishing
Thread-safe operations with mutex protection

Definition in file ImuMinimal.cpp.

Macro Definition Documentation

◆ TS_PRINT

#define TS_PRINT ( msg )

Value:

    do                                            \
    {                                             \
        int64_t __ts = _apps_time_monotonic_ns(); \
        printf("[TS %ld ns] %s\n", __ts, msg);    \
    } while (0)

Definition at line 82 of file ImuMinimal.cpp.

Function Documentation

◆ _imu_data_handler_cb()

void _imu_data_handler_cb	(	int	ch,
		char *	data,
		int	bytes,
		void *	context
	)

Handler for incoming IMU data.

This callback processes incoming IMU data, updates the system state, and triggers appropriate processing based on motion state. It serves as the primary entry point for all IMU data processing in the system.

The function performs the following operations:

Validates and parses IMU data packets
Updates frame transformation based on gravity direction
Converts IMU data to OpenVINS format
Performs batch processing to reduce mutex operations
Feeds IMU data to the VIO manager
Synchronizes camera data with IMU timestamps
Triggers VIO processing and data publishing

The function uses batch processing to minimize mutex contention at high IMU frequencies and ensures proper temporal synchronization between IMU and camera data.

Parameters

ch	Channel number (unused)
data	Pointer to IMU data buffer
bytes	Size of data buffer in bytes
context	Context pointer (unused)

Definition at line 114 of file ImuMinimal.cpp.

References active_callbacks, en_debug, frame_transform, CameraQueueFusion::getInstance(), voxl::Publisher::getInstance(), CameraQueueFusion::getSortedBatch(), imu_model, is_imu_connected, is_resetting, last_imu_timestamp_ns, voxl::Publisher::publish(), reset_cv, reset_mtx, vio_error_codes, and vio_manager.

Referenced by connect_imu_service().

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◆ _imu_disconnect_cb()

void _imu_disconnect_cb	(	__attribute__((unused)) int	ch,
		__attribute__((unused)) void *	context
	)

Callback for IMU disconnect events.

This function is called when the IMU service disconnects. It handles the cleanup and state management required when IMU data becomes unavailable.

The function uses thread-safe mutex locking to ensure proper state management during disconnection events.

Parameters

ch	Channel number (unused)
context	Context pointer (unused)

Definition at line 283 of file ImuMinimal.cpp.

References IMU_CH, imu_lock_mutex, and is_imu_connected.

Referenced by connect_imu_service().

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◆ connect_imu_service()

int connect_imu_service ( void )

Creates IMU pipe client and associated callbacks.

This function sets up the disconnect and data handler callbacks, and opens the client pipe connection to the IMU service. It initializes the complete IMU data pipeline for the VIO system.

The function performs the following operations:

Sets up disconnect callback for graceful handling of service disconnection
Sets up data handler callback for processing incoming IMU measurements
Configures thread priority for high-frequency IMU processing
Opens the client pipe connection to the IMU service
Configures the pipe for optimal data flow
Sets the IMU connection status flag

Returns: 0 on success, -1 on failure

Definition at line 315 of file ImuMinimal.cpp.

References _imu_data_handler_cb(), _imu_disconnect_cb(), IMU_CH, imu_name, is_imu_connected, PROCESS_NAME, and vio_error_codes.

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Variable Documentation

◆ imu_lock_mutex

std::mutex imu_lock_mutex

Mutex for IMU data access synchronization.

Mutex used to synchronize access to IMU data between multiple threads.

Definition at line 80 of file ImuMinimal.cpp.

Referenced by _imu_disconnect_cb().

Macros

Functions

Variables