Android: Getting data simultaneously from Accelerometer and Gyroscope

Question

I'm having some issues getting data from the accelerometer and gyroscope simultaneously. I need to use these sensors to get acceleration and orientation in order to calculate relative position for a project I'm working on. When both sensors are used at the same time it leads to some very weird data output, in which the data only changes once every second. When only the accelerometer is run the data is not much better because it is only changing roughly 10 times a second on its fastest setting. This data is printed out to a file with a time stamp for each sensor reading.

I'm having trouble finding tutorials on the internet, particularly using more than one sensor together at the same time. Do I need to put each sensor on a different thread? I don't have much experience using threads, how could I do this.

Answer 1

You don't need to put each sensor on a different thread. Yo can use the class SensorManager to register and unregister the different sensors that you need

public class SensorActivity extends Activity, implements SensorEventListener {
 private final SensorManager mSensorManager;
 private final Sensor mAccelerometer;
 private final Sensor mGyroscope;

 public SensorActivity() {
     mSensorManager = (SensorManager)getSystemService(SENSOR_SERVICE);
     mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
     mGyroscope = mSensorManager.getDefaultSensor(TYPE_GYROSCOPE);
 }

 protected void onResume() {
     super.onResume();
     mSensorManager.registerListener(this, mAccelerometer, SensorManager.SENSOR_DELAY_NORMAL);
     mSensorManager.registerListener(this, mGyroscope, SensorManager.SENSOR_DELAY_NORMAL);
 }

 protected void onPause() {
     super.onPause();
     mSensorManager.unregisterListener(this);
 }

Implements the sensorEventList handler (specially the method onSensorChanged) and check who belongs the received data:

 public void onSensorChanged(SensorEvent sensorEvent) {
    sensorName = sensorEvent.sensor.getName();
    Log.d(sensorName + ": X: " + sensorEvent.values[0] + "; Y: " + sensorEvent.values[1] + "; Z: " + sensorEvent.values[2] + ";");

}

Answer 2

Java code

import android.content.pm.ActivityInfo;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.content.Context;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
    TextView textX, textY, textZ;
    SensorManager sensorManager;
    Sensor sensor;
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        sensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
        sensor = sensorManager.getDefaultSensor(Sensor.TYPE_GYROSCOPE);
        textX = findViewById(R.id.textX);
        textY = findViewById(R.id.textY);
        textZ = findViewById(R.id.textZ);
        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
    }
    public void onResume() {
        super.onResume();
        sensorManager.registerListener(gyroListener, sensor, SensorManager.SENSOR_DELAY_NORMAL);
    }
    public void onStop() {
        super.onStop();
        sensorManager.unregisterListener(gyroListener);
    }
    public SensorEventListener gyroListener = new SensorEventListener() {
        public void onAccuracyChanged(Sensor sensor, int acc) {
        }
        public void onSensorChanged(SensorEvent event) {
            float x = event.values[0];
            float y = event.values[1];
            float z = event.values[2];
            textX.setText("X : " + (int) x + " rad/s");
            textY.setText("Y : " + (int) y + " rad/s");
            textZ.setText("Z : " + (int) z + " rad/s");
        }
    };
}

    

XML file code

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">
    <TextView
        android:id="@+id/textX"
        android:layout_width="209dp"
        android:layout_height="79dp"
        android:layout_marginStart="91dp"
        android:layout_marginLeft="91dp"
        android:layout_marginEnd="111dp"
        android:layout_marginRight="111dp"
        android:gravity="center"
        android:text=""
        android:textSize="30sp"
        app:layout_constraintBottom_toTopOf="@+id/textY"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="1.0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        tools:ignore="MissingConstraints" />
    <TextView
        android:id="@+id/textY"
        android:layout_width="209dp"
        android:layout_height="79dp"
        android:layout_marginStart="91dp"
        android:layout_marginLeft="91dp"
        android:layout_marginEnd="111dp"
        android:layout_marginRight="111dp"
        android:layout_marginBottom="8dp"
        android:gravity="center"
        android:text=""
        android:textSize="30sp"
        app:layout_constraintBottom_toTopOf="@+id/textZ"
        app:layout_constraintEnd_toEndOf="@+id/textX"
        app:layout_constraintHorizontal_bias="0.445"
        app:layout_constraintStart_toStartOf="@+id/textX"
        app:layout_constraintTop_toBottomOf="@+id/textX"
        tools:ignore="MissingConstraints" />
    <TextView
        android:id="@+id/textZ"
        android:layout_width="209dp"
        android:layout_height="79dp"
        android:layout_marginStart="153dp"
        android:layout_marginLeft="153dp"
        android:layout_marginEnd="49dp"
        android:layout_marginRight="49dp"
        android:layout_marginBottom="241dp"
        android:gravity="center"
        android:text=""
        android:textSize="30sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="@+id/textY"
        app:layout_constraintHorizontal_bias="0.757"
        app:layout_constraintStart_toStartOf="@+id/textY"
        app:layout_constraintTop_toBottomOf="@+id/textY"
        tools:ignore="MissingConstraints" />
</android.support.constraint.ConstraintLayout>

Answer 3

This Kotlin solution is derived from Kroka's solution:

class MainActivity : AppCompatActivity(), SensorEventListener {

    private lateinit var mSensorManager:SensorManager
    private lateinit var mAccelerometer :Sensor
    private lateinit var mGyroscope :Sensor

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        mSensorManager = getSystemService(Context.SENSOR_SERVICE) as SensorManager
        mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER)
        mGyroscope = mSensorManager.getDefaultSensor(TYPE_GYROSCOPE)
    }

    override fun onAccuracyChanged(sensor: Sensor?, accuracy: Int) {

    }
    override fun onSensorChanged(event: SensorEvent?) {
        val sensorName: String = event?.sensor!!.getName();
        Log.d("Sensor",sensorName + ": X: " + event.values[0] + "; Y: " + event.values[1] + "; Z: " + event.values[2] + ";")
    }

    override fun onResume() {
        super.onResume()
        mSensorManager.registerListener(this, mAccelerometer, SensorManager.SENSOR_DELAY_NORMAL)
        mSensorManager.registerListener(this, mGyroscope, SensorManager.SENSOR_DELAY_NORMAL)
    }

    override fun onPause() {
        super.onPause()
        mSensorManager.unregisterListener(this)
    }

}