FXOS8700CQ
Freescale Semiconductor
This application note demonstrates the auto-calibration function of the FXOS8700CQ.
Application NoteNxp
NXP AN4459: Using the FXOS8700CQ Auto-Calibration Function
Guide to using the FXOS8700CQ auto-calibration function for hard-iron compensation in eCompass applications on platforms with limited processing power and memory.
Overview
This application note explains the implementation of the auto-calibration function within the FXOS8700CQ 6-axis sensor. It describes how the device uses the min/max averaging method to calculate hard-iron estimates and automatically subtract them from magnetic field readings. The document outlines two primary strategies: Calibrate-then-Compensate and Calibrate-and-Compensate. It also covers magnetic jamming detection using vector magnitude thresholds to prevent contamination of the calibration data. Technical details include register configurations for M_CTRL_REG1 and M_CTRL_REG2, along with Python code examples for system integration.
Use Cases
- Developing eCompass functionality for low-power mobile platforms.
- Implementing automatic magnetic calibration in wearable devices like smartwatches.
- Compensating for hard-iron interference from on-board components like speakers.
- Configuring magnetic vector magnitude events for interference detection.
Topics
FXOS8700CQ
auto-calibration
hard-iron compensation
eCompass
magnetometer
magnetic field
jamming detection
min/max averaging
NXP
Freescale
Referenced Parts
| FXOS8700CQ | Freescale Semiconductor | This application note demonstrates the auto-calibration function of the FXOS8700CQ. |