APM 2.6 Compass change - beeping

Hello everyone,
I have one issue with my 2.6 board.
I figured out that my external compas is not ok, so I
switched to the one I have on GPS module.
I connected SCA and SCL to I2C port.
I recallibrated the compass and it points in the right direction in Mission planner.
Now every time I connect the battery, I hear 5 beeps.
It arms ok, and I don’t see any warning in mission planner.
What would that be?

Concerning the 5 beeps - what battery are you using and is your copter a tri-, a quad, or a hex?

Concerning the connector that goes from the GPS unit to the flight controller board - can you, by visually examining it, tell if the plug would also be able to be plugged into the socket just above the side port?

(On my 2.6 module’s case there is a “GPS” stenciled in white just between the two sockets [the one on the side and the one on the top])

If it appears that it can fit that socket you might consider trying it there

Thank you for your answer!
I have a quad with 6s batteries.

The beeping occurs, when I connect the compass to I2C port.
I have GPS and compass connected like on the pic below.
If I disconnect compass there is no beeping (but obviously mission planner
shows message “bad compass health”).

I managed to resolve the issue.
As can be seen on the picture, only
sda and scl are connected to I2C port,
so I did the same.

Then I made 2 y cables and connected ground and
5v to both gps port and to I2C port.
It stopped beeping at startup and also
flies completely normal now.

Thanks for help anyway!

So you are saying the compass works okay and the GPS works properly too?

Prior to making your y-cables, did you try unplugging the orange-blue wires from the I2C socket and plugging them into the yellowish-colored socket just below the “GPS” on your case?

It should have worked in that socket - without any need for additional wiring.

Ok, that is a good idea.
But I cannot find any pinout information
about this “old style GPS port”. So I don’t
know which are rx, tx for gps, and sca, scl for compass.
(I modified the cable, so I cannot just plug it in)