Gyroscope vs accelerometer?

Question

Now that iOS 4 is no longer an NDA, I would like to know what Gyroscope has to offer through Accelerometer for developers. Is there any difference in the API? Other things?

Answer 1

Gyro MEMs are the rate of change of a device. When the device rotates on any of its axes, you can see the change in rotation. The accelerometer only provides force along the vectors X, Y, and Z and cannot solve the "turbulence." Using both sensors, you can often implement what is called an inertial system 6DOF (degrees of freedom), or dead calculation, which allows you to find the relative physical location of the device. (Note that all inertial systems drift, so it is unstable in the long run).

In short: gyroscopes measure rotation, accelerometers measure translation.

To read the gyro there is a new API .

Answer 2

In fact, the accelerometer measures linear acceleration; but since force is equal to the acceleration of mass, people can consider it a measuring force, as well as constant mass. Linear acceleration is the rate of change of linear velocity. A gyroscope, on the other hand, provides angular speed measurements as opposed to linear acceleration of motion. Both sensors measure the rate of change; they simply measure the rate of change for different things.

Technically, a linear accelerometer can measure rotation speed. This is due to the centrifugal force that the device generates when it rotates. Centrifugal force is directly related to its rotation speed. In fact, many MEMS gyroscopic sensors actually use linear accelerometers to determine rotational speed, carefully placing them in specific orientations and measuring centrifugal forces to calculate the actual gyroscope rotation speed.