adding new sensors to multiwii

Hi guys just need some help though some of you may be familiar with multiwii
one of its aging sensor the HMC5883l is getting really hard to come by . though with a help from another memeber we added the QMC 5883 to the lists. now Im asking help again to add the MCC5883 into multiwii just to keep it alive. I see that its the most basic arduino drone one could build but not every one has an idea how to keep it going .

the original thread
http://www.multiwii.com/forum/viewtopic.php?f=6&t=8069

looking to expand its features too later on
here the updated link if anyone would be interested to add anew host of sensors , gyros , accelerators,compass ,barometers , lidar or something
http://www.multiwii.com/forum/viewtopic.php?f=6&t=8711

this time adding the MMC 3885 to the code

this is the original thread here how to fake hmc5883l (qmc5883l) connect to the multiiwii code ??? - Sensors - Arduino Forum