我正在尝试分析来自Galaxy Nexus的一堆Android传感器数据，并且我遇到了一些奇怪的模式。例如，磁场传感器的重复值为8，屏幕方向传感器的重复值为255。这些值似乎在我阅读的文档中没有任何特殊意义，但它们反复弹出。任何人都知道为什么？
我包含传感器数据输出的样本，以防任何人想要它，0表示在收听时间段（1分钟）内没有返回数据。每行不同5分钟：
MPU6500 Acceleration Sensor AK09911C Magnetic field Sensor AK09911C Magnetic Sensor UnCalibrated MPU6500 Gyroscope Sensor MPU6500 Uncalibrated Gyroscope Sensor Barometer Sensor TMG399X Proximity Sensor TMG399X RGB Sensor MPL Rotation Vector MPL Game Rotation Vector SAMSUNG Step Detector Sensor SAMSUNG Step Counter Sensor SAMSUNG Significant Motion Sensor MAX86900 Screen Orientation Sensor HRM Sensor Orientation Sensor Gravity Sensor Linear Acceleration Sensor
-0.7918822 -1.44 8 -0.0010652645 0 0 0.027657 -0.00831 107.56043 0 0 255 0 0 -0.79049826 0.005798638 344.4021 -0.7916513 0.012937188
-1.6178818 18.66 -1.14 8 8 0 0.028444 -0.008315 0 0 0 255 0 0 -1.6365771 0.04024315 110.17886 -1.6392937 0.029791594
-1.638831 8 8 -2.66E-04 0 0.047552 -0.03045 0 0 0 255 0 0 0 -1.6823589 0.04951334 352.47757 -1.6795416 0.03173232
-1.6753427 -1.08 8 -0.0026631611 0 0.048844 -0.030235 0 1 0 255 0 0 0 -1.7105712 0.07293725 103.25511 -1.7080178 0.043449044
-1.721431 8 8 0.0013315806 0.0013315806 0.044273 -0.03007 0 0 0 255 0 0 0 -1.7184123 0.013740659 358.64462 -1.7213204 0.008867621
-1.7154455 18.72 -1.08 8 0.046393 -0.030042 0 0 0 255 0 0 0 0 -1.7471539 0.020335913 97.08981 -1.7468109 0.036153793
-1.8076223 -1.08 8 -0.0034621095 -0.0034621095 0 0.032184 -0.052209 0 0 0 255 0 0 -1.8572613 0.07178533 9.031282 -1.849128 0.043301344
-1.7962499 -1.08 8 8 -0.051598 -0.050319 1 0 0 255 0 0 0 0 -1.8097965 0.018933535 98.16796 -1.8121501 0.0069220066
-1.7830818 14.4 8 8 0 0 0.031865 -0.051793 0 0 0 0 0 255 -1.8501818 0.051537752 6.3113422 -1.8480959 0.033290982
-1.8968062 -1.02 8 8 0 0.035205 -0.051669 0 0 0 0 255 0 0 -1.9285302 0.06584132 9.900935 -1.9213988 0.02040255
-1.846528 15.06 8 8 0 0 0 88.72001 -0.0386 -1.8738624 255 0 0 0 -1.8782147 0.009540319 13.564674 -1.8787019 0.023794174
-1.2557588 18.6 8 8 0.002130529 -0.056822 -0.059393 0 0 255 0 0 1 0 -1.2829624 0.013437033 99.33356 -1.2816399 0.024684072
-1.2449849 18.6 8 0.014114754 0 0 0 85.962204 0.003289 -0.057907 -1.2985611 0 0 255 -1.2931483 0.042776465 14.364091 -1.2938662 0.037508845
-1.2443863 18.54 -1.26 8 8 0 0 -0.054567 -0.056251 2.5835018 0 0 255 0 -1.2474166 -0.011933446 93.84088 -1.2518827 -0.0062702894
-1.1426327 18.72 8 8 0 -0.052494 -0.056559 1 0 0 255 0 0 0 -1.1527904 0.017340302 6.746513 -1.1546664 0.01502645
-1.1492168 18.6 8 8 0.002396845 0 -0.048156 -0.04867 0 0 255 0 0 0 -1.1757433 0.03131497 99.13985 -1.1777196 0.019524574
-1.4927847 8 -2.66E-04 0 0 0.031505 -0.028662 0 0 255 0 0 1 0 -1.5062454 0.024833083 7.337884 -1.5073864 0.029565454
-1.5041572 18.78 0.005060006 8 8 0 0 -0.023542 -0.027803 5.926271 0 0 255 0 -1.5276097 0.030635118 91.725334 -1.527528 0.038933158
-1.5143325 -1.08 8 8 5.33E-04 0 0 0 0 -0.027872 0.04729855 85.258766 -1.529908 0 255 -1.5293596 0.009041548 -1.5280322 0.033451796
-1.4993688 14.52 8 8 0 -0.023884 -0.026326 0 0 255 0 0 0 0 -1.5211747 0.03198123 93.13916 -1.526189 0.013652086
-0.9816227 18.48 -1.32 8 8 0 0 0 -0.020971 -0.0265 -1.526189 0.5559387 7.78904 255 -1.0139774 0.030559063 85.279945 -1.0111967 0.031968236
-0.9756372 18.6 -1.2 8 8 0 0 -0.006156 -0.011322 0 0 255 0 1 -0.9895226 -0.0034725666 11.263685 -0.9939272 0.0069175363
-0.9923966 18.54 8 8 -0.0037284256 0 -0.010102 -0.010804 0 0 0 0 255 0 -1.011731 0.015144587 95.325294 -1.0129408 0.02712822
-0.7445967 0.12 8 8 0 -0.007972 -0.010841 0 0 255 0 0 0 0 -0.76289475 0.030269027 99.85943 -0.7639039 0.028285444
-0.18794483 19.62 -0.18 8 0 0 0.029863 0.031101 0 0 255 0 0 0 -0.19251534 0.0069647133 22.254642 -0.19720303 0.021827757
答案 0 :(得分：0)
使用我的三星Galaxy S5（G900I）时，屏幕方向传感器会在设备方向已知时返回设备在[0,3]（含）范围内的方向。当方向不确定时，它返回255.
例如，如果设备的正面或背面是平的，则传感器会报告255.同样，如果设备位于两个方向（纵向和横向）之间，传感器会报告255.
这完全基于我自己的观察而不是文档，因为屏幕方向传感器似乎不是标准的。 （我不记得在Android开发者文档中看到过对这个传感器的任何引用，并且SDK似乎也没有引用它。）