为什么我的陀螺仪传感器返回的值始终为零？

Question

 if (timestamp != 0) {
                final float dT = (event.timestamp - timestamp) * NS2S;
                // Axis of the rotation sample, not normalized yet.
                double axisX = event.values[0];
                double axisY = event.values[1];
                double axisZ = event.values[2];
}
timestamp = event time

我想读取3轴上的值。但传感器返回的值始终为零