Use 3 compasses

good morning everyone, I would like to ask you a question about compass, and I have a pixhawk 2.4.8 fw 3.6.12 with two m8n gps and two compasses connected to the i2c splitter, and everything works properly, I tried to also insert the internal compass of the FC, but in the calibration phase I do not see it working while if I use the first external compass, and the second internal works well.
If, on the other hand, if the 1st external is used, the 2nd external and 3rd internal function only 1 and 2.
Is there the possibility of making all three work?

Are the compasses on both GPS same? If yes, I think they both are using same address and you are able to access only one Compass.

Thanks for the answer, they are two identical M8N gps with integrated compass, and both work well at the same time, the only thing is that I can’t make the internal compass of the pixhawk work together with the other two m8n,

I don’t think I2C bus recognizes compasses with same device ID as 2 independent compasses. Can you go to Initial setup on MP and share screenshot of HW ID?

I see 2 of them, do you agree?

you are right on i2c there is only one while the inner one is on the isp, do you know how to change the address to the compass so that it works both?

You will not be able to change the address and further the internal compass on most Flight Controllers, including the 2.4.8 you have, are prone to noise and are generally only a source of compass inconsistent errors rather than of any benefit.

I would like to change the address to one of the two m8n if possible and eliminate the internal compass so that they can both work in parallel on the i2c splitter
This is possible?