Problem with heading (compass)

Getting Started Newbie Questions
#1

Hello,
I wanted to use the heading but geographic property is always -1. Only magnetic shows a value between 0 and 360 but it seems that this north is not fixe, megnetic north moves !? [import]uid: 107239 topic_id: 24949 reply_id: 324949[/import]

#2

I think -1 means my Nexus S doesn’t integrate a geographic compass. [import]uid: 107239 topic_id: 24949 reply_id: 101520[/import]