Most Freefly products use MEMS sensors which have pros and cons. The pros are they are very small, lightweight, and inexpensive. The Cons are that they can drift, are not immune to shock / vibration, and are not as precise as higher end gyros like Fiber Optic or Laser Ring Gyros.
A properly functioning, well calibrated, and properly initialized Freefly product that uses a MEMS sensor is expected to drift up to 3 degrees/minute.
Typically drift (as opposed to IMU corruption) will be seen on the pan axis only. Tilt and Roll axis have the benefit of an accelerometer to help null out any gyro drift.
There are some things you can do to minimize drift.
- Make sure to keep the unit absolutely still while initializing. This will set the initial offset and is critical for minimizing drift
- Allow product to acclimate to the intended operating temperature. Large variations in temperature can induce drift.
If you experience excessive drift we recommend:
- Restarting product ensuring complete stability on boot up
- Use a compass / GPS assisted mode to allow for longer term heading stability (compass has its own host of issues with magnetic interference etc to watch out for)
- Ensuring that spurious commands are not being sent to the product. For example a MoVI Controller with pan trim enabled might look just like a pan drift, but in fact be a valid command to the MoVI.
- Ensure the joystick on the MoVI Controller was centered upon startup. To reset the joystick center point reboot the controller.