检测iPhone屏幕方向

Question

我想以45度的增量检测iPhone的方向.理想情况下,我希望能够沿任何轴获得方向角.

我需要做的检测类似于当T方向改变时,iPhone的Trism如何向屏幕的当前底部位置闪烁箭头.

我有一些编码,但实际上不明白加速度计读数如何工作,可以使用正确方向的微调.我当前的代码记录了当前的角度,但即使手机是平的,我的读数每秒也会变化很多.

- (void) checkOrientation:(UIAccelerometer*)accelerometer didAccelerate:(UIAcceleration*)acceleration
{
    int accelerationX = acceleration.x * kfilteringFactor + accelerationX * (1.0 - kfilteringFactor);
    int accelerationY = acceleration.y * kfilteringFactor + accelerationY * (1.0 - kfilteringFactor);

    float currentRawReading = (atan2(accelerationY, accelerationX)) * 180/M_PI;
    NSLog(@"Angle: %f",currentRawReading);
}

手机平放时来自日志的样本:

2009-06-16 17:29:07.987 [373:207] Angle: 0.162292
2009-06-16 17:29:07.994 [373:207] Angle: 179.838547
2009-06-16 17:29:08.014 [373:207] Angle: 179.836182
2009-06-16 17:29:08.032 [373:207] Angle: -90.000000
2009-06-16 17:29:08.046 [373:207] Angle: 179.890900
2009-06-16 17:29:08.059 [373:207] Angle: -90.000000
2009-06-16 17:29:08.074 [373:207] Angle: 179.917908
2009-06-16 17:29:08.088 [373:207] Angle: -179.950424
2009-06-16 17:29:08.106 [373:207] Angle: 90.000000
2009-06-16 17:29:08.119 [373:207] Angle: 90.000000
2009-06-16 17:29:08.134 [373:207] Angle: -179.720245

Answer 1

我认为您的问题是您在需要时使用int变量float。

我认为– accelerationX和–Y应该是实例变量，因此：

accelerationX = acceleration.x * kfilteringFactor + accelerationX * (1.0 - kfilteringFactor);
accelerationY = acceleration.y * kfilteringFactor + accelerationY * (1.0 - kfilteringFactor);

应该给您更多您想要的东西。