Parameters Tested

Key Parameters

Following are the parameters that are important for marine use. Each link leads to more details and test results.

Magnetic Interference Somewhat important is immunity to external magnetic interference. Vessels using a traditional compass already take measures to minimize interference (e.g. by separating electrical wires from compass, removing ferromagnetic metals from the vicinity). Once installed, and the sensor is calibrated, one should be able to rely on the magnetic environment remaining similar and the reported heading correct.
Calibration Process Version 7 of the sensor fusion software has the ability to self-calibrate the magnetometer while in use, and initial impressions are that this feature compensates for at least some transient perturbations in the magnetic environment.
Temperature Of IC Die While not essential to providing vessel orientatation, temperature may be useful if it turns out that calibration accuracy is affected noticeably by the IC temperature.

Version 7.2 of NXP's sensor fusion software is a marked improvement over the version 4.2 fusion code. Improvements include:

better code structure. It is amenable to adapting for other applications by having separate files for functions like control, sensor IO, calibration storage, fusion algorithm, status, etc.
magnetic calibration runs as a background task while in regular operation
fast execution. The fusion algorithm operates with a cycle time of less than 900 us (ESP32 CPU) on data from sensors sampled at 200 Hz, giving position updates at 40 Hz.
improved balance between gyro, accelerometer, and magnetometer inputs during rapid jerky motion. Subjectively, this algorithm settles faster than version 4.2.