Android P九轴传感器数据读取

「爱情、让人受尽委屈。」 2024-04-20 09:27 54阅读 0赞

相关资料：  
[https://www.st.com/zh/mems-and-sensors/lsm9ds1.html\#tools-software][https_www.st.com_zh_mems-and-sensors_lsm9ds1.html_tools-software]  
[https://github.com/STMicroelectronics/STMems\_Android\_Sensor\_HAL\_IIO][https_github.com_STMicroelectronics_STMems_Android_Sensor_HAL_IIO]  
[https://www.st.com/content/st\_com/zh/products/embedded-software/mems-and-sensors-software/drivers-for-mems/androidhal-iio.html][https_www.st.com_content_st_com_zh_products_embedded-software_mems-and-sensors-software_drivers-for-mems_androidhal-iio.html]

陀螺仪，Gyroscope，GYRO-Sensor，通过测量自身的旋转状态，判断出设备当前运动状态，是向前、向后、向左还是向右，是加速还是减速。

加速度计，Accelerometer，G-Sensor，重力感应器，可以感知任意方向上的加速度，可以感知受力情况。

磁力计，Magnetic，M-Sensor，测试磁场强度和方向，定位设备的方位，可以测量出东南西北四个方位的夹角。

总之，陀螺仪知道我们转了几个圈，加速度计知道我们向前走了几米，磁力计知道我们的方位。

安卓中通过监听SensorEventListener来获取传感器的数据。

事件类型：

import android.hardware.Sensor;
    public static final String STRING_TYPE_TEMPERATURE = "android.sensor.temperature";
    public static final int TYPE_ACCELEROMETER = 1;							 //加速度计
    public static final int TYPE_ACCELEROMETER_UNCALIBRATED = 35;
    public static final int TYPE_ALL = -1;
    public static final int TYPE_AMBIENT_TEMPERATURE = 13;
    public static final int TYPE_DEVICE_PRIVATE_BASE = 65536;
    public static final int TYPE_GAME_ROTATION_VECTOR = 15;
    public static final int TYPE_GEOMAGNETIC_ROTATION_VECTOR = 20;
    public static final int TYPE_GRAVITY = 9;
    public static final int TYPE_GYROSCOPE = 4;										//陀螺仪
    public static final int TYPE_GYROSCOPE_UNCALIBRATED = 16;
    public static final int TYPE_HEART_BEAT = 31;
    public static final int TYPE_HEART_RATE = 21;
    public static final int TYPE_LIGHT = 5;
    public static final int TYPE_LINEAR_ACCELERATION = 10;
    public static final int TYPE_LOW_LATENCY_OFFBODY_DETECT = 34;
    public static final int TYPE_MAGNETIC_FIELD = 2;								//磁力计
    public static final int TYPE_MAGNETIC_FIELD_UNCALIBRATED = 14;
    public static final int TYPE_MOTION_DETECT = 30;

注册监听：

sensorManager.registerListener(this,
            sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD),
            SensorManager.SENSOR_DELAY_NORMAL);
    
    sensorManager.registerListener(this,
            sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD_UNCALIBRATED),
            SensorManager.SENSOR_DELAY_NORMAL);
    
    sensorManager.registerListener(this,
            sensorManager.getDefaultSensor(Sensor.TYPE_GYROSCOPE),
            SensorManager.SENSOR_DELAY_NORMAL);

完整代码：

public class MainActivity extends AppCompatActivity implements SensorEventListener{ 
        private static final String TAG = "Magnetometer";
        private TextView magnetometer_value;
        private TextView accelerometer_value_X;
        private TextView accelerometer_value_Y;
        private TextView accelerometer_value_Z;
        private TextView gyroscope_value_X;
        private TextView gyroscope_value_Y;
        private TextView gyroscope_value_Z;
        private SensorManager sensorManager;
        public static DecimalFormat DECIMAL_FORMATTER;
    
        //Accelerometer
        float[] accelerometerValues = new float[3];
        float[] gravity = new float[3];
        float[] linear_acceleration = new float[3];
        float[] magneticValues = new float[3];
    
        //Gyroscope
        private static final float NS2S = 1.0f / 1000000000.0f;
        private final float[] deltaRotationVector = new float[4];
        private float timestamp;
    
        @Override
        protected void onCreate(Bundle savedInstanceState) { 
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            Log.i(TAG,"Magnetometer,onCreate");
            magnetometer_value = (TextView) findViewById(R.id.magnetometer_value);
            accelerometer_value_X = (TextView) findViewById(R.id.accelerometer_value_X);
            accelerometer_value_Y = (TextView) findViewById(R.id.accelerometer_value_Y);
            accelerometer_value_Z = (TextView) findViewById(R.id.accelerometer_value_Z);
            gyroscope_value_X = (TextView) findViewById(R.id.gyroscope_value_X);
            gyroscope_value_Y = (TextView) findViewById(R.id.gyroscope_value_Y);
            gyroscope_value_Z = (TextView) findViewById(R.id.gyroscope_value_Z);
            // define decimal formatter
            DecimalFormatSymbols symbols = new DecimalFormatSymbols(Locale.US);
            symbols.setDecimalSeparator('.');
            DECIMAL_FORMATTER = new DecimalFormat("#.#", symbols);
            sensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
    
            if (sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD) != null){ 
                // Success! There's a magnetometer.
                Log.i(TAG,"Magnetometer,Success! There's a magnetometer.");
            } else { 
                // Failure! No magnetometer.
                Log.i(TAG,"Magnetometer,Failure! No magnetometer.");
            }
        }
        @Override
        protected void onResume() { 
            super.onResume();
            Log.i(TAG,"Magnetometer,onResume");
    
            if (sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD) != null){ 
                // Success! There's a magnetometer.
                Log.i(TAG,"Magnetometer,Success! There's a magnetometer.");
            } else { 
                // Failure! No magnetometer.
                Log.i(TAG,"Magnetometer,Failure! No magnetometer.");
            }
            sensorManager.registerListener(this,
                    sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD),
                    SensorManager.SENSOR_DELAY_NORMAL);
    
            sensorManager.registerListener(this,
                    sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD_UNCALIBRATED),
                    SensorManager.SENSOR_DELAY_NORMAL);
    
            sensorManager.registerListener(this,
                    sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER),
                    SensorManager.SENSOR_DELAY_NORMAL);
    
            sensorManager.registerListener(this,
                    sensorManager.getDefaultSensor(Sensor.TYPE_GYROSCOPE),
                    SensorManager.SENSOR_DELAY_NORMAL);
    
        }
        @Override
        protected void onPause() { 
            super.onPause();
            sensorManager.unregisterListener(this);
        }
        @Override
        public void onSensorChanged(SensorEvent event) { 
            //Log.i(TAG,"onSensorChanged,event=" + event);
            if ( event.sensor.getType() == Sensor.TYPE_MAGNETIC_FIELD ) { 
                Log.i(TAG,"onSensorChanged,TYPE_MAGNETIC_FIELD");
                // get values for each axes X,Y,Z
                float magX = event.values[0];
                float magY = event.values[1];
                float magZ = event.values[2];
                double magnitude = Math.sqrt((magX * magX) + (magY * magY) + (magZ * magZ));
                // set value on the screen
                magnetometer_value.setText( DECIMAL_FORMATTER.format(magnitude) + " \u00B5Tesla");
            }else if( event.sensor.getType() == Sensor.TYPE_MAGNETIC_FIELD_UNCALIBRATED ){ 
                Log.i(TAG,"onSensorChanged,TYPE_MAGNETIC_FIELD");
            }else if( event.sensor.getType() == Sensor.TYPE_ACCELEROMETER ){ 
                //Log.i(TAG,"onSensorChanged,TYPE_ACCELEROMETER");
    
                accelerometerValues = event.values.clone();
    
                // alpha is calculated as t / (t + dT)
                // with t, the low-pass filter's time-constant
                // and dT, the event delivery rate
                final float alpha = 0.8f;
                gravity[0] = alpha * gravity[0] + (1 - alpha) * event.values[0];
                gravity[1] = alpha * gravity[1] + (1 - alpha) * event.values[1];
                gravity[2] = alpha * gravity[2] + (1 - alpha) * event.values[2];
                linear_acceleration[0] = event.values[0] - gravity[0];
                linear_acceleration[1] = event.values[1] - gravity[1];
                linear_acceleration[2] = event.values[2] - gravity[2];
                accelerometer_value_X.setText(DECIMAL_FORMATTER.format( accelerometerValues[0]));
                accelerometer_value_Y.setText(DECIMAL_FORMATTER.format( accelerometerValues[1]));
                accelerometer_value_Z.setText(DECIMAL_FORMATTER.format( accelerometerValues[2]));
            }else if( event.sensor.getType() == Sensor.TYPE_GYROSCOPE ){ 
                // This time step's delta rotation to be multiplied by the current rotation
                // after computing it from the gyro sample data.
                if (timestamp != 0) { 
                    final float dT = (event.timestamp - timestamp) * NS2S;
                    // Axis of the rotation sample, not normalized yet.
                    float axisX = event.values[0];
                    float axisY = event.values[1];
                    float axisZ = event.values[2];
    
                    // Calculate the angular speed of the sample
                    float omegaMagnitude = (float)Math.sqrt(axisX*axisX + axisY*axisY + axisZ*axisZ);
    
                    // Normalize the rotation vector if it's big enough to get the axis
                    if (omegaMagnitude > EPSILON) { 
                        axisX /= omegaMagnitude;
                        axisY /= omegaMagnitude;
                        axisZ /= omegaMagnitude;
                    }
    
                    // Integrate around this axis with the angular speed by the time step
                    // in order to get a delta rotation from this sample over the time step
                    // We will convert this axis-angle representation of the delta rotation
                    // into a quaternion before turning it into the rotation matrix.
                    float thetaOverTwo = omegaMagnitude * dT / 2.0f;
                    float sinThetaOverTwo = (float)Math.sin(thetaOverTwo);
                    float cosThetaOverTwo = (float)Math.cos(thetaOverTwo);
                    deltaRotationVector[0] = sinThetaOverTwo * axisX;
                    deltaRotationVector[1] = sinThetaOverTwo * axisY;
                    deltaRotationVector[2] = sinThetaOverTwo * axisZ;
                    deltaRotationVector[3] = cosThetaOverTwo;
                    gyroscope_value_X.setText( DECIMAL_FORMATTER.format( axisX));
                    gyroscope_value_Y.setText(  DECIMAL_FORMATTER.format( axisY));
                    gyroscope_value_Z.setText( DECIMAL_FORMATTER.format( axisZ));
                }
                timestamp = event.timestamp;
                float[] deltaRotationMatrix = new float[9];
                SensorManager.getRotationMatrixFromVector(deltaRotationMatrix, deltaRotationVector);
                // User code should concatenate the delta rotation we computed with the current
                // rotation in order to get the updated rotation.
                // rotationCurrent = rotationCurrent * deltaRotationMatrix;
            }
        }
        @Override
        public void onAccuracyChanged(Sensor sensor, int accuracy) { 
            Log.i(TAG,"onSensorChanged,sensor=" + sensor);
            Log.i(TAG,"onSensorChanged,accuracy=" + accuracy);
        }
    }

[https_www.st.com_zh_mems-and-sensors_lsm9ds1.html_tools-software]: https://www.st.com/zh/mems-and-sensors/lsm9ds1.html#tools-software
[https_github.com_STMicroelectronics_STMems_Android_Sensor_HAL_IIO]: https://github.com/STMicroelectronics/STMems_Android_Sensor_HAL_IIO
[https_www.st.com_content_st_com_zh_products_embedded-software_mems-and-sensors-software_drivers-for-mems_androidhal-iio.html]: https://www.st.com/content/st_com/zh/products/embedded-software/mems-and-sensors-software/drivers-for-mems/androidhal-iio.html