Tutorial - What The User Needs to Know to Build The First Application¶
The OpenIMU Core is the foundation for the Platform application and all other example and custom applications. However, it is not supplied as a separate application. The OpenIMU Core provides the Board Support Package (BSP), FreeRTOS, command line interface capability, filters, GPS interface capability, math functionality, and various utilities, including the base examples for the C-language main function and the data acquisition functionality.
EZ Embed Example Applications
The following applications are implicitly based on use of an EZ Embed* OpenIMU unit, such as the OpenIMU300ZA.
To get you acquainted with the OpenIMU environment, let’s walk through the development of the following applications:
All the examples that follow are based on the Framework application that ships installed on the OpenIMU. This framework serves as a stating point upon which user-applications can be built. Descriptions of all common components are provided in the Framework Application Link below.
The term Inertial Measurement Unit (IMU) refers to a device that returns calibrated inertial-sensor data. This application forms the backbone of all other example applications as each requires inertial measurements to generate other results.
The Static-Leveler application uses accelerometer readings to measure the local gravity-field and compute the two-axis attitude (roll and pitch angles) of a body relative to the local-level frame. A Leveler application could be used to provide stabilization for cameras and other systems that require linear and rotational stability.
The Vertical Gyro (VG) application and the Attitude and Heading Reference System (AHRS) application use rate-sensors, accelerometers, and (for the AHRS application) magnetometers to compute the attitude and heading of a body in space. Rate-sensors are used to propagate the attitude forward in time at high output data-rates (ODR) while accelerometers and magnetometers act as references, correcting for rate-sensor biases and attitude errors.
The Inertial Navigation System (INS) application supports all of the features and operating modes of the VG&AHRS applications. In addition it includes the additional capability of interfacing with an external GPS receiver and associated software running on the processor for computation of navigation position information as well as orientation information.
Robust CAN Example Applications
There are two CAN example applications, one for each CAN message protocol specifications used:
- SAE J1939 Messaging Standard. The SAE J1939 standards document set provides the requirements for the CAN messaging implementation implemented in this example application
- DBC Messaging Specification. The Database Communication (DBC) CAN message format is a proprietary format developed and released by the company Vector Informatik GmbH. It is an optional addition for applications that use J1939 protocols.
CAN provisioned units can run most of the example applications described in the EZ Embed section, so description of those applications are not provided here. The CAN example applications implement the IMU Application functionality.