IMU Compass "Boat is Level" and offsets lost after rebooting or restarting signalk

[Saqqara]

In the manual and your video you only show use of The Boat Is Level button and not the directional offset. I have been trying to orient the thing using the heading from the ship's compass and using offset until it is correct. Is that not necessary?

If you want to have correct compass heading you need to do it. Otherwise you will have a relative heading and the values for pitch and roll won't be right (swapped if 90 degrees off)

I suppose the imu might sense which way it is accelerating and report that as heading? If that is the case it might read differently than the ship's compass if drifting sideways...

It cannot sense heading from acceleration. It may be possible for it to use gps to know the direction it goes, and also gps location to subtract the magnetic deviation, but as you say, it won't work if the ship is not moving in the direction it is facing, such as drifting, beating or in currents.

There are all kinds of ways to make it smarter. It could probably "auto level" with the right logic, but for now, you need to level, then dial in the compass offset to align the sensors. Let us know if you have ideas to improve things.

Thank you. I am just the fool to help make documentation foolproof. The only suggestion I have is an Apply button to save these inputs immediately, but I expect there is a good reason you don't do that.

So calibration runs continuously whether the window is open or not, and the calibration button only opens the window, it doesn't initiate anything (although without the inputs it won't point correctly)?





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