Xtrinsic Sensor Fusion Library for Kinetis MCUs

In my December post, New sensor expansion boards for Freedom development platform, I introduced you to the FRDM-FXS sensor shields for the platform. From the “Downloads” tab on the FRDM-FXS-MULTI-B webpage, you can now download demo executables for the FRDM-KL25Z and FRDM-K20D50M boards that are compatible with Xtrinsic Sensor Fusion Toolbox for Android.

The links for the two executable are labeled FRDM-K20D50M_MQXL (compiled for ARM® Cortex-M4) and FRDM-KL25Z-MQXL (compiled for Arm Cortex-M0+). You will need to log in our community and accept a click-through license/disclaimer to gain access to the files.

One of the things I like most about the Freedom development platform is its ease of use. It can be programmed with a bootloader that allows you to plug the board into your PC via USB, and install software (such as these files) with a simple drag and drop. If you haven’t done this before, let me recommend a couple of resources for you:

• The PE Micro OpenSDA support page has links for windows USB drivers, Freedom board bootloader and more
• The OpenSDA User’s Guide should teach you everything else you need to about OpenSDA

Now here is the really cool part, the embedded fusion library at the heart of this functionality is now available in via the “Xtrinsic Sensor Fusion Library for Kinetis MCUs – Evaluation Version and documentation” link, available from the same Downloads tab listed above. The download package includes a datasheet describing Xtrinsic Sensor Fusion capabilities, a user’s guide that will show you how to get up and running, and a zip file containing a CodeWarrior project. The evaluation version runs only on the KL25Z board. Everything in the project, with the exception of one .c file, is precompiled. Filename user_tasks.c is reserved for your use, and allows you to insert code at 5 specific entry points in the project. You have visibility to all fusion outputs, and can modify the Bluetooth output stream to suite your own needs. This is the same project used to create the executables mentioned earlier. The evaluation version is fully compatible with the Xtrinsic Sensor Fusion Toolbox.

The evaluation version of the kit is intended to give developers everything they need to evaluate the quality and scope of sensor fusion libraries. Once a decision is made to incorporate the library into a product, you will want to upgrade to the “product development” version of the library. This version, which will soon be available from the same download page, provides many more bells and whistles with regard to fusion options and underlying project structure. Differences in the three versions of the library are summarized below:

The next table shows sensor fusion features versus sensor complement used for the application. See the sensor fusion datasheet for additional restrictions/details.