Tag Configuration and Sensor Calibration

This section includes:

Tag Configuration

Sewio Tag Leonardo configuration can be done in two ways → by NFC or Wirelessly.

The configuration by NFC is done by a smartphone with NCF interface and installed Android app. The wireless configuration is done by UWB radio of a selected Anchor. Old Tags can be configured only via console.

Sewio recommends using NFC configuration.

Sensor Calibration

When the tag is configured and the sensors are activated, each sensor needs to be calibrated. The Tag Leonardo range can be calibrated wirelessly. Older tags as Tag Li-Ion and Tag iMU can be calibrated via console. 

For the magnetometer, accelerometer, and gyroscope, the calibration is used to remove zero offsets. It is necessary to do this calibration if the user wants to use the spatial rotation determination. It can be useful even if raw data from sensors are sent to the server for further processing.

Magnetometer calibration

Every magnetometer has an issue that is called “hard-iron offset”. This can be removed by using the magnetometer calibration. The user must rotate the tag around all axes for 25 seconds. This procedure must be performed in an environment without any strong magnetic interference.

Inertial measurement unit calibration 

Both inertial sensors: accelerometer and gyroscope also have zero offsets. They should be calibrated too if one wants to use spatial rotation determination.