External compass not detected on Pixhawk

Hi ,
I bought pixhawk from china and pluged in ublox neo 7m gps+compass. But pixhawk does not recognize the external compass. I wonder if it is I2C port on pixhwak a problem or is it gps compass (Here i want to mention that I had a bad crash before with this gps compass on so not sure if crash can destroy the compass). Please any suggestion will be appreciated



Look with Mission Planner if the external compass is detected.
You should see in full parameters tree , in the Compass section, two different numbers for ID value

Mission planner shows only one compass which is internal compass it. It does not shoe the external compass from ublox gps

If the RGB led connected to I2C port of the Pixhawk works it is likely that your GPS on board compass is defective since even if the I2C port on the Chinese Pixhawk would have some problems at least it should show the external compass.