PitLab Autopilot User Manual page 20

Autopilot – User's manual
Well calibrated gyroscope should has values "Axis X", "Axis Y" and "Axis
Z" near zero. It may fluctuate, but it's value should be not bigger then
+/-10 units. If offset is bigger on any axis, it means the gyroscope
require calibration.
First autopilot board need to be cooled (e.g. in refrigerator, covered
with plastic bag). When board is stable, press button "Write min". Next
allow to slowly warm up board to room temperature (close to 25°C)
and press button "Write mid". Finally heat the board using hair dryer
or other safe heat source and press "Write max".
For cooling can be used outdoor temperatures in winter, ice cube in
foil bag or specialized cooling spray. Using ice or sprays please cover
the electronics with thin tissue to absorb water condensing from air.
Correct sequence: first cooling, next heating allow to evaporate
potentially condensed moisture.
To calibrate via OSD menu go to OSD menu "Service" → "IMU
calibration" → "Thermal calibration" and follow instruction on the
screen. First you will be asking for calibrate "mid" temperature and
don't moving the model while calibration, next cooling and calibrating
"low" temperature. Finally heating and calibrating "high" temperature.
© Pit Lab 2017 https://www.pitlab.com/fpv-system/autopilot.html
Calibrating magnetometer
Principle of magnetometer calibration is to find minimal and maximal
magnetic field value for all axis. To do it, the autopilot board (or whole
plane with it) should be oriented to the magnetic north direction in 3
different position to calibrate all 3 axis.
The calibration can be done via FPV Manager at office condition or via
OSD menu outdoor. The outdoor conditions are recommended,
because inside building the magnetic field can be highly distorted by
iron used in building construction. In both ways of calibration, user is
asked to keep the autopilot oriented to described direction in 3D
space. To do it precise the magnetic compass will be useful to precise
determine north direction before calibration.
Note: The compass is also the source of magnetic field, so when is
kept in close distance to magnetometer on autopilot's board, it may
distort the Earth magnetic field. Take it away from board during
calibration.
To calibrate using FPV Manager use "Autopilot" → "Calibration". In
"Magnetometer" section, press "Zero" button and follow instruction
displayed in window. Place autopilot board or whole plane in
requested position and press the button "Calibrate 1". Follow the same
operation for next 2 steps in any order.
Page 20 of 21