Gravity sensor listener not working
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I want to get accelerometer sensor data which is in earth axis through a service. I read about a way to do it as well on one of the posts on stackoverflow. But I have an issue.
@Override public void onSensorChanged(SensorEvent event) { Toast.makeText(this, "Hollyy shiiitt",Toast.LENGTH_SHORT); String acceldata = ""; float[] gravityValues = null; float[] magneticValues = null; if (event.sensor.getType() == Sensor.TYPE_GRAVITY) { gravityValues = event.values.clone(); Toast.makeText(this, "The gra data is " + String.valueOf(gravityValues), Toast.LENGTH_SHORT); } if ((gravityValues != null) && (magneticValues != null) && (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER)) { // float for use in conversion device relative acceleration to earth axis acceleration float[] deviceRelativeAcceleration = new float[4]; deviceRelativeAcceleration[0] = event.values[0]; deviceRelativeAcceleration[1] = event.values[1]; deviceRelativeAcceleration[2] = event.values[2]; deviceRelativeAcceleration[3] = 0; // Change the device relative acceleration values to earth relative values // X axis -> East // Y axis -> North Pole // Z axis -> Sky float[] R = new float[16], I = new float[16], earthAcc = new float[16]; SensorManager.getRotationMatrix(R, I, gravityValues, magneticValues); float[] inv = new float[16]; android.opengl.Matrix.invertM(inv, 0, R, 0); android.opengl.Matrix.multiplyMV(earthAcc, 0, inv, 0, deviceRelativeAcceleration, 0); acceldata = String.valueOf(lat) + "," + String.valueOf(lon) + "," + String.valueOf(speed)+","+ String.valueOf(earthAcc[0]) + "," + String.valueOf(earthAcc[1]) + "," + String.valueOf(earthAcc[2])+ "," + String.valueOf(event.values[0])+ "," + String.valueOf(event.values[1])+ "," + String.valueOf(event.values[2]); } //SDK version check if(Build.VERSION.SDK_INT > 18) { File file; FileWriter filew; // Internal Storage writing try { file = new File(getExternalFilesDir(Environment.DIRECTORY_DOCUMENTS) + "/" + filename); //Android 4.4 and above filew = new FileWriter(file, true); //true for append filew.write(acceldata + String.valueOf(gravityValues) + String.valueOf(magneticValues) + "\n"); filew.close(); } catch (Exception e) { e.printStackTrace(); } } else{ String data = acceldata + "\n" ; try { FileOutputStream fOut = openFileOutput("/" + filename,Context.MODE_APPEND); fOut.write(data.getBytes()); fOut.close(); Toast.makeText(getBaseContext(),"file saved",Toast.LENGTH_SHORT).show(); } catch (IOException e) { e.printStackTrace(); Toast.makeText(getBaseContext(),"file not saved API < 19",Toast.LENGTH_SHORT).show(); } } }
The if statement for gravity sensor on location changed doesn't return any value so the next statement also doesn't work as gravityValues has a null value.
The sensors registered are
mAccelerometer = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER); mMagnetsensor = sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD); mGravity = sensorManager.getDefaultSensor(Sensor.TYPE_GRAVITY);
They are then registered as
int SamplingFrequency = 2 * 100000; // delay in microsecond. in this case 0.2 second sensorManager.registerListener(this, mAccelerometer,SamplingFrequency); sensorManager.registerListener(this, mMagnetsensor, SamplingFrequency); sensorManager.registerListener(this,mGravity,SamplingFrequency);
I am a newbie in app development so any help would be appreciated.
Yes, without doing anything complex, check if you are getting values from gravity sensor if (event.sensor.getType() == Sensor.TYPE_GRAVITY) { System.out.println("X: " + event.values[0]); System.out.println("Y: " + event.values[1]); System.out.println("Z: " + event.values[2]); }
How can you be not sure. If you use the snippet and get x,y, and z values then there is nothing wrong with it, the next step is the track where you omit the values. If https://www.developerbook.net/ you are a newbie, strip the code to the core and check each step. Create sensormanger, https://chatrandom.download get gravity sensor from sensormanager, register it onResume and onSensorChanged check if you get the output from gravity sensor
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