Openxsensor magnetometer calibration

[Drashiel]

Hi,
How can I calibrate my compass on a GY-86 module? URL comes on description to parse samples are not available.
I get those values on debug:
-326 , -54 , 423 - -169 -15 71 ==> 176
-325 , -57 , 422 - -168 -31 -58 ==> 51
-325 , -56 , 422 - -168 71 18 ==> -134
-324 , -55 , 420 - -168 -17 54 ==> 175
-326 , -57 , 420 - -168 74 -6 ==> -134
-326 , -57 , 420 - -168 35 -30 ==> -125
-327 , -58 , 418 - -168 53 33 ==> -139
Is the last value on every row heading?
I did ACC calibration prior enable debug on compass.
Thanks.
Regards.