I am planning to develop an accelerometer based mouse on the android platform. the mobile device which i plan to use is htc nexus one. the cursor should move as the mobile is moved is space. will that be difficult compard to movement wrt gravity?
A:
this is hard to answer due to way you have phrased the question.
What is it you are wanting to use the mouse for? If you are trying to move the mouse on a computer, you will need to also create a software package that the PC can run that has the ability to set the position of the mouse.
The accelerators in phones detect, obviously, acceleration, usually in the x y and Z axis. If you lay your phone on the table, you will notice the phone is under 1g (lower all or capital case should that be?). This is actually 1g of acceleration, even though it is not accelerating you still have it. You can detect the roll of a phone by recording how the component of this 1g differs in the three axis. ie you have equal g force in the x and z axis and zero in the y, then you can 'assume' the phone is being held at a 45 degree angle.
When the sum of the components is not equal to 1g, your know your phone is actually accelerating. However, you need to know the position of your phone. Due to a delightfully painful way maths works, if you work out the differential of the differential of the acceleration of your phone (in each axis) you should have the position. The exact way you work out position from acceleration is more then I can think of in the morning, but the relation ships are fairly simple to convert to/from, if you keep a constant for them all, which you can, TIME!
thecoshman
2010-03-29 07:43:14