Hi there and thank you for your response.
Yes your correct I am having compass issues, the GPS itself works like a trooper but the compass not so much.
I originally looked at the Zubax because I had run out of UART ports and wanted dual GPS for better accuracy. However after reading the literature and watching the reviews on Youtube I quickly realized that the Zubax out performed most other general GPS. So I put it on my list as a possible solution. However I soon solved the UART problem and shelved the Zubax idea.
Once the machine was air worthy I took it to the field and test flew it. I then performed a review of the logs and much to my surprise was finding Compass health issues. After a couple weeks I traced it to a faulty I2C hub. Replacing the hub solved the health issue but I was left with the inability to properly calibrate the compass.
I came to the conclusion I had 1 of 2 problems…or possibly both. First I2C line noise as there are a number of I2C devices and second, Nearness to high power leads. The GPS/Compass combo is under a plastic canopy and with the canopy off the same errors occurred. I even replaced the GPS/Compass with another and the problem still continued. At this point I decided to do two things. Not wanting to just do a half ass job on it. I orderd the Zubax GNSS and tore the machine down. I have since redesigned the top plate of the craft and will move the GPS/Compass to the rear of the craft away from as much wiring as possible, move the PDB to the front of the machine and switch to the GNSS to remove the I2C line as a possible cause.
As for the FC Compass, I never use it however in this instance its the only compass I could successfully calibrate…go figure.
So in the next couple weeks I will reassemble the machine and see how it goes after that.
Here is a photo of the machine in its assembled state, before I stripped it