Why does Band have both gyrometer and accelerometer/gyro?

[Teeceman]

Any ideas why the band has a gyrometer as well as a gyro within the 3-axis accelerometer/gyro?
What would be the difference uses for each type?

 

[navierstokez]

accelerometer measures linear acceleration - think a car moving in a straight line
gyrometer measures rotational acceleration- think things spinning

accelerometer: steps, jumping up and down, gravitational pull, impulses, cornering Gs
gyro: swinging motion of your arms, twisting of your wrist

 

[Teeceman]

Thanks for breaking it down, I understand the functionalities, I guess I was wondering what benefits the extra gyometer brings to the Band as I guess the accelerometer would be 3 axis..

 

[BADM0USE]

hmmm? A more precise measurement maybe?

 

[DroidUser42]

I think the issue about having just an accelerometer, is it knows it's moving, but the gyro helps it know which direction (with respect to "up") it's going.

Is the Band swinging back and forth with the arm hanging down, or is it bouncing up/down while jogging with the arms in a "L" position? The accelerometer is going to say the same thing either way. Because the movement is in same direction with respect to the Band itself. But the gyro knows which way is "up". Which helps the software understand what the movement means.

 

[William Stogin]

I initially also thought that gyro acceleration was measuring angular acceleration, but upon writing an android app I printed out these log statements:


07-08 13:29:48.473 12183-13701/<package name> V/GyroscopeManager: X: 0.9863281
07-08 13:29:48.473 12183-13701/<package name> V/GyroscopeManager: Y: -0.0014648438
07-08 13:29:48.473 12183-13701/<package name> V/GyroscopeManager: Z: -0.020019531
07-08 13:29:48.480 12183-13646/<package name> V/AccelerometerManager: X: 0.9863281
07-08 13:29:48.480 12183-13646/<package name> V/AccelerometerManager: Y: -0.0014648438
07-08 13:29:48.480 12183-13646/<package name> V/AccelerometerManager: Z: -0.020019531

These were printed while the band was at rest on a table, so there should be zero angular acceleration. To the contrary, the band registers the exact same as the accelerometer. I would be interested to hear the reason behind this. Furthermore, I have issues maintaining connectivity when streaming both accelerometer and gyroscope at high frequencies at the same time. To avoid this problem, they should really get rid of the BandAccelerometerEventListener class and have people just get acceleration from the gyroscope.

Edit:
Sorry, this might not be what you are looking for. I thought I was on something more like StackOverflow. The gyroscope also provides angular velocity, which the accelerometer doesn't provide. If I had to guess, I would say they come from the same physical sensor and just have more complex calculations to get the angular velocity.