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Table of Contents

  1. Voxl IIM Server
  2. Configuration
  3. Usage
  4. Published Format

Voxl IIM Server

The Voxl IIM Server receives and publishes data from the tdk-iim 46234 and 46230 IMUs on the pipe imu_iim.

Configuration

The Voxl IIM server uses the configuration file located at: /etc/modalai/voxl-iim-server.conf. The config file contains the following fields:

  • bus integer, default = 1
  • imu_sample_rate_hz integer (hz), default = 1000
  • imu_baud_rate_hz integer (baud), default = 921600
  • imu_fsr_gyro integer (dps), default = 480
  • imu_fsr_accel integer (g), default = 8

Usage

The server runs as a service in the background which can be started/stopped with systemctl start/stop voxl-iim-server. The server can also be run manually from the shell using the command voxl-iim-server. There are also optional arguments that can be added when running the server manually such as:

  • voxl-iim-server -d to enable debug prints
  • voxl-iim-server -t to enable timestamp prints for the IMU packets
  • voxl-iim-server -c to create a new config file and exit
  • voxl-iim-server -h to print a help menu

To check the satus of the server run voxl-inspect-services and find the voxl-iim-server. The data can be viewed by running the command voxl-inspect-imu imu_iim or by going to the IMUs tab under debug in the portal and selecting the desired IMU imu_iim.

Published Format

IMU data is published to the pipes in an imu_data_t struct which consists of the following:

  • struct imu_data_t:
  • uint32_t magic_number Set to IMU_IMAGE_MAGIC_NUMBER for frame syncing
  • float accl_ms2[3] XYZ acceleration in m/s^2
  • float gyro_rad[3] XYZ gyro rotation in rad/s
  • float temp_c temp in C, IMU_INVALID_TEMPERATURE_VALUE if no thermometer
  • uint64_t timestamp_ns timestamp in nanoseconds, uses system clock_monotonic