The aim of this thread is to provide a list of Android devices (existing and coming) with gyros - And to promote the value of having gyros in mobiles.
IPhones have gyros, but unfortunately very few Android devices have them so far.
So what is the gyro good for ? In short, in combination with the accelerometer it can produce fast and reliable measurements of the angular position of the device in space - roll , pitch and yaw.
Okay, the accelerometer can also measure the angular position - but not fast and reliable. Measurements are either 'shaky' or 'sloppy'. What the accelerometer really measures is a combination of gravity and 'changes in velocity'. The gravity direction relative to the device changes with the angular position of the device, and so can be used to determine the angular position. But the measurements also contain a part coming from velocity changes caused by a shaking hand. Good enough for rotating the screen, but not for smooth control needed by a game for instance. To get rid of the shakiness you have to filter the measurements, and then you get a sloppy response.
The gyro, on the other hand, measures angular velocity or 'changes in angle'. It is very fast and measurements are not influenced by vibrations. But, because it doesn't measure exact angles but angular velocity you have to integrate the measurements to get angular positions, and small inaccuracies will cause the angular position to drift.
So a gyro alone is not good for measuring angular position. But if you let the accelerometer take care of precise but slow changing position and the gyro take care of the fast changes, you have an ideal combination which produces fast and precise measurements, which can be used to provide a very fast and smooth control based on angular position in space.
My interest in this comes from developing a generic input method based on rolling and pitching - not a game. I have two devices for testing: a SonyEricsson with only an accelerometer and a Samsung (Google) Nexus S, which also have a gyro. And the difference is like night and day. After having used months experimenting with advanced filter techniques (4th order Bessel filters and Kalman filters) I came to the conclusion, that without a gyro, the control is ether shaky or sloppy - or both. In a few weeks you will be able to download my app and try it yourself.
So I will start the list with my two devices:
Samsung Nexus S : got
SonyEricsson Xperia x8: not
I hope some of you will help me with more informations for my 'Android gyro list'
Best Regards
Hardy Henneberg
IPhones have gyros, but unfortunately very few Android devices have them so far.
So what is the gyro good for ? In short, in combination with the accelerometer it can produce fast and reliable measurements of the angular position of the device in space - roll , pitch and yaw.
Okay, the accelerometer can also measure the angular position - but not fast and reliable. Measurements are either 'shaky' or 'sloppy'. What the accelerometer really measures is a combination of gravity and 'changes in velocity'. The gravity direction relative to the device changes with the angular position of the device, and so can be used to determine the angular position. But the measurements also contain a part coming from velocity changes caused by a shaking hand. Good enough for rotating the screen, but not for smooth control needed by a game for instance. To get rid of the shakiness you have to filter the measurements, and then you get a sloppy response.
The gyro, on the other hand, measures angular velocity or 'changes in angle'. It is very fast and measurements are not influenced by vibrations. But, because it doesn't measure exact angles but angular velocity you have to integrate the measurements to get angular positions, and small inaccuracies will cause the angular position to drift.
So a gyro alone is not good for measuring angular position. But if you let the accelerometer take care of precise but slow changing position and the gyro take care of the fast changes, you have an ideal combination which produces fast and precise measurements, which can be used to provide a very fast and smooth control based on angular position in space.
My interest in this comes from developing a generic input method based on rolling and pitching - not a game. I have two devices for testing: a SonyEricsson with only an accelerometer and a Samsung (Google) Nexus S, which also have a gyro. And the difference is like night and day. After having used months experimenting with advanced filter techniques (4th order Bessel filters and Kalman filters) I came to the conclusion, that without a gyro, the control is ether shaky or sloppy - or both. In a few weeks you will be able to download my app and try it yourself.
So I will start the list with my two devices:
Samsung Nexus S : got
SonyEricsson Xperia x8: not
I hope some of you will help me with more informations for my 'Android gyro list'
Best Regards
Hardy Henneberg