Publish the IMU data with qrb_ros_imu - Qualcomm Dragonwing Documentation

The qrb_ros_imu sample application publishes the inertial measurement unit (IMU) data collected from the ICM-42688 hardware on Qualcomm Robotics Platforms. It provides the following:

Composable ROS Node support.
Zero-Copy transport powered by QRB ROS Transport.

Pipeline flow for `qrb_ros_imu`

The following figure shows the pipeline flow for qrb_ros_imu.

Inertial measurement unit hardware feeding the QRB-ROS-IMU node, which gets the data from SLPI and publishes it to a ROS topic. — qrb_ros_imu pipeline.

The qrb_ros_imu is a ROS 2 package. It creates a publisher with qrb_ros_transport for zero-copy transport. It supports node composition, making it possible to improve performance using ROS intra-process communication.

`qrb_ros_imu` APIs

The qrb_ros_imu package exposes ROS interfaces, ROS parameters, and the qrb_sensor_client library APIs. Use them to subscribe to the published inertial measurement unit (IMU) data and to configure how the node reads the sensor.

ROS interfaces

The following table describes the ROS interfaces provided by qrb_ros_imu.

Interface	Name	Type	Description
`Publisher`	`/imu`	`sensor_msgs/msg/Imu`	Outputs the inertial measurement unit (IMU) data.

ROS parameters

The following table describes the ROS parameters for qrb_ros_imu.

Name	Type	Description	Default value
`debug`	`bool`	To measure the latency from IMU data generation to its output by the ROS node.	`false`

`qrb_sensor_client` APIs

The following table describes the qrb_sensor_client APIs.

Function	Parameters	Description
`bool create_connection()`	Empty	Connect with sensor service, return `true` means create successfully.
`void disconnect_server()`	Empty	Disconnect with sensor service.
`bool get_imu_data(sensors_event_t accel_ptr, sensors_event_t gyro_ptr, int32_t * sample_count)`	• `accel_ptr`: Pointer to accelerometer data • `gyro_ptr`: Pointer to gyroscope data • `sample_count`: Number of samples available	Retrieves IMU data. Returns `true` if successful. If `true`, `accel_ptr` and `gyro_ptr` point to the latest IMU data, and `sample_count` specifies how many samples are retrieved.

Prerequisites

You have set up the device, installed ROS2 Jazzy and Qualcomm Intelligent Robotics (QIR) SDK on the device according to Install the QIR SDK.

Run out-of-the-box `qrb_ros_imu`

Install the qrb_ros_transport packages

Install the packages

sudo apt install ros-jazzy-qrb-ros-imu
sudo apt install qcom-sensor\*
reboot

Use the IMU node

Run the IMU node

source /opt/ros/jazzy/setup.bash
ros2 run qrb_ros_imu imu_node

Check ROS topics with the topic /imu

source /opt/ros/jazzy/setup.bash
ros2 topic echo /imu

Build and run `qrb_ros_imu`

Install dependencies

Install the dependencies

sudo apt install ros-jazzy-qrb-ros-transport-imu-type \
ros-dev-tools

Clone the repository to the device

Download the source code

mkdir -p ~/qrb_ros_ws/src
cd ~/qrb_ros_ws/src
git clone https://github.com/qualcomm-qrb-ros/qrb_ros_imu.git

Build and run qrb_ros_imu

Build and run

cd ~/qrb_ros_ws
colcon build
source install/setup.bash
ros2 run qrb_ros_imu imu_node

​Pipeline flow for qrb_ros_imu

​qrb_ros_imu APIs

​ROS interfaces

​ROS parameters

​qrb_sensor_client APIs

​Prerequisites

​Run out-of-the-box qrb_ros_imu

​Build and run qrb_ros_imu