Hi. I'm completely new to arduino and I'm looking for some advice. I'm designing and hope to prototype a product for sports applications to track & improve performance. Ideally I'd like to transmit accelerometer, gyroscope & magnetometer data to a smart phone and I'm wondering if it's possible to do this without powering the sensors? An example of what I mean would be something like the Tag system that GameGolf use (http://www.gamegolf.com/products/en-us/tags?v=eac2654). As far as I'm aware their Tags require no power.
Any advice would be great appreciated.
G.