If you wish to use the offset calibration or crosstalk calibration functions of the regular MappyDot (not Plus) you will need to upgrade to the 1.5 firmware release, as there is a bug that prevents the calibration data from being loaded.

There is a firmware update guide available now which walks through the update process:

https://sensordots.org/firmwareguide

If you are running an older version, it's worthwhile to upgrade as there are a bunch of new features such as:

• Auto address recovery.
• Custom measurement mode profiles.
• Soft interrupt command.
• AmbientRateRtnMegaCps and SignalRateRtnMegaCps commands.
• Tweaks to filtering.
• And lots of minor bug fixes.