I want to mount a sensor in an object that will lie flat most of the time. But when it's picked up and moved I want to be able to detect that. Just an accelerometer isn't good enough because I also need to know if it's flat and right-side-up. An accelerometer will notice the object is moving, but when they put it down again, I need to know if it's flat and right-side-up. This is going to be battery powered, so I need a low current solution. Ideally, something that will sleep until there's movement. Any suggestions?
An accelerometer will work to detect movement, and to detect the angle it is resting at. The Z axis of the accelerometer should register the acceleration due to gravity while at rest and flat. If the sensor is at an angle, the value of the Z axis will change.