Motore acceso??

Il problema e' questo : e' possibile determinare se una macchina ferma ha il motore acceso o meno usando un telefono Android??

Si tratta di un problema per una app che dovevo fare ma che poi non ha mai visto la luce e la risposta e' si'....usando la FFT sui dati dell'accelerometro

Il primo grafico e' relativo ad una misura di 30 secondi a macchina ferma e spenta, il secondo sempre su una acquisizione di 30 secondi a macchina ferma ed accesa al minimo del motore

E' abbastanza evidente una frequenza di risonanza della macchina su tutti e tre gli assi intorno ai 40 Hz (il motore girava intorno ai 900 rpm ma quello che si registra e' la vibrazione di tutta la struttura)

Foto ed imageview su Android

Aggiornamento: facendo delle prove con Nexus 5x e Nexus 9 ho scoperto che l'immagine risulta ruotata di 90° nonostante non ci siano modifiche nel codice
A questo link viene descritto il medesimo problema

Un sistema per una app che scatta una foto e mette il risultato in una imageview ed effettua il salvataggio (gestione dei permessi di scrittura non gestita..vedi post precedenti)



-----------------------------------------------

package com.example.lucainnocenti.photonotation;

import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.drawable.BitmapDrawable;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;


public class MainActivity extends AppCompatActivity {
    private static final int CAMERA_REQUEST = 1888;
    private ImageView foto;
    private Bitmap ff;


    @Override    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        foto = (ImageView) findViewById(R.id.imageView);
        Button scatto = (Button) findViewById(R.id.button);


        scatto.setOnClickListener(new View.OnClickListener() {
            @Override            public void onClick(View view) {
                Intent camera = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                startActivityForResult(camera, CAMERA_REQUEST);
            }
        });


    }
    protected void onActivityResult(int requestCode,int resultCode, Intent data)
    {
        if (requestCode== CAMERA_REQUEST && resultCode == Activity.RESULT_OK){
            ff = (Bitmap) data.getExtras().get("data");
            foto.setImageBitmap(ff);
            foto.setImageURI(data.getData());
            Bitmap bm=((BitmapDrawable)foto.getDrawable()).getBitmap();
            saveImageFile(bm);
        }

    }

    public String saveImageFile(Bitmap bitmap) {
        FileOutputStream out = null;
        String filename = getFilename();
        try {
            out = new FileOutputStream(filename);
            bitmap.compress(Bitmap.CompressFormat.PNG, 100, out);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
            Log.d("luca22","Errore");
        }
        return filename;
    }

    private String getFilename() {
        File file = new File(Environment.getExternalStorageDirectory()
                .getPath(), "TestFolder");
        if (!file.exists()) {
            file.mkdirs();
        }
        String uriSting = (file.getAbsolutePath() + "/"                + System.currentTimeMillis() + ".jpg");
        Log.d("luca22",uriSting);
        return uriSting;
    }
}

Azimuth Pitch e Roll su Android N

Gestione dei sensori con RotationMatrix su Android



--------------------------------------------------------------

package com.example.lucainnocenti.sensori;

import android.content.Context;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;

public class MainActivity extends AppCompatActivity implements SensorEventListener{

    private SensorManager mSensorManager;
    private final float[] mAccelerometerReading = new float[3];
    private final float[] mMagnetometerReading = new float[3];

    private final float[] mRotationMatrix = new float[9];
    private final float[] mOrientationAngles = new float[3];
    private Sensor mAccelerometer;
    private Sensor mMagnetometer;

    private double az;
    private double pi;
    private double ro;


    @Override    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
        mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
        mMagnetometer = mSensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD);


    }

    @Override    public void onAccuracyChanged(Sensor sensor, int accuracy) {

    }

    @Override    protected void onResume() {
        super.onResume();

        mSensorManager.registerListener(this, mAccelerometer, SensorManager.SENSOR_DELAY_NORMAL, SensorManager.SENSOR_DELAY_UI);
        mSensorManager.registerListener(this, mMagnetometer, SensorManager.SENSOR_DELAY_NORMAL, SensorManager.SENSOR_DELAY_UI);

    }

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

    @Override    public void onSensorChanged(SensorEvent event) {

        if (event.sensor == mAccelerometer) {
            System.arraycopy(event.values, 0, mAccelerometerReading, 0, mAccelerometerReading.length);
        }
        else if (event.sensor == mMagnetometer) {
            System.arraycopy(event.values, 0, mMagnetometerReading, 0, mMagnetometerReading.length);
        }
        updateOrientationAngles();
    }


    public void updateOrientationAngles() {
        mSensorManager.getRotationMatrix(mRotationMatrix, null, mAccelerometerReading, mMagnetometerReading);
        mSensorManager.getOrientation(mRotationMatrix, mOrientationAngles);
        az = Math.toDegrees(mOrientationAngles[0]);
        pi = Math.toDegrees(mOrientationAngles[1]);
        ro = Math.toDegrees(mOrientationAngles[2]);
        Log.d("orienta", "Az:"+String.valueOf(az)+" Pi:"+String.valueOf(pi)+" Ro:"+String.valueOf(ro));

    }
}

GPS su Android N

Un esempio di uso del GPS su Android N con getione dei permessi. Evidenziate in giallo le parti di codice di gestione dei permessi


---------------------------------------------------

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.example.lucainnocenti.gpstest">
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />


    <application        android:allowBackup="true"        android:icon="@mipmap/ic_launcher"        android:label="@string/app_name"        android:roundIcon="@mipmap/ic_launcher_round"        android:supportsRtl="true"        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

---------------------------------------------------



---------------------------------------------------

package com.example.lucainnocenti.gpstest;

import android.Manifest;
import android.content.Context;
import android.content.DialogInterface;
import android.content.pm.PackageManager;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;

public class MainActivity extends AppCompatActivity implements LocationListener{

    LocationManager locationManager;
    String provider;
    public static final int MY_PERMISSIONS_REQUEST_LOCATION = 99;

    @Override    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

        provider = locationManager.getBestProvider(new Criteria(), false);

        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            checkLocationPermission();
            return;
        }
        Location location = locationManager.getLastKnownLocation(provider);

        if (location != null) {

            Log.i("Location Info", "Location achieved!");

        } else {

            Log.i("Location Info", "No location :(");

        }
    }

    @Override    protected void onResume() {
        super.onResume();

        if (checkLocationPermission()) {
            if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
                locationManager.requestLocationUpdates(provider, 400, 1, this);
            }
        }

    }

    @Override    protected void onPause() {
        super.onPause();

        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            checkLocationPermission();
            return;
        }
        locationManager.removeUpdates(this);

    }

    @Override    public void onLocationChanged(Location location) {

        Double lat = location.getLatitude();
        Double lng = location.getLongitude();

        Log.i("Location info: Lat", lat.toString());
        Log.i("Location info: Lng", lng.toString());

    }

    @Override    public void onStatusChanged(String provider, int status, Bundle extras) {

    }

    @Override    public void onProviderEnabled(String provider) {

    }

    @Override    public void onProviderDisabled(String provider) {

    }

    public void getLocation(View view) {

        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {

            return;
        }
        Location location = locationManager.getLastKnownLocation(provider);

        onLocationChanged(location);


    }

    public boolean checkLocationPermission() {
        if (ContextCompat.checkSelfPermission(this,
                Manifest.permission.ACCESS_FINE_LOCATION)
                != PackageManager.PERMISSION_GRANTED) {

            if (ActivityCompat.shouldShowRequestPermissionRationale(this,Manifest.permission.ACCESS_FINE_LOCATION)) {


                new AlertDialog.Builder(this)
                        .setTitle("Permesso GPS")
                        .setMessage("Permesso GPS")
                        .setPositiveButton("Ok", new DialogInterface.OnClickListener() {
                            @Override                            public void onClick(DialogInterface dialogInterface, int i) {
                                //Prompt the user once explanation has been shown                                ActivityCompat.requestPermissions(MainActivity.this,
                                        new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
                                        MY_PERMISSIONS_REQUEST_LOCATION);
                            }
                        })
                        .create()
                        .show();


            } else {
                ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, MY_PERMISSIONS_REQUEST_LOCATION);
            }
            return false;
        } else {
            return true;
        }
    }

    @Override    public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
        switch (requestCode) {
            case MY_PERMISSIONS_REQUEST_LOCATION: {
                if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                    if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
                        locationManager.requestLocationUpdates(provider, 400, 1, this);
                    }

                } else {

                    // permission denied,

                }
                return;
            }

        }
    }
}

Scrittura JSON su Android N

Un esempio semplice per scrivere un file JSON e gestire in permessi di scrittura su Android 7 e successivi
Nel codice le parti in azzurro sono quelle relative alla gestione dei permessi mentre quelle in giallo sono per la gestione della creazione del JSON


---------------------------------------

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.example.lucainnocenti.jsontester">
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />



    <application        android:allowBackup="true"        android:icon="@mipmap/ic_launcher"        android:label="@string/app_name"        android:roundIcon="@mipmap/ic_launcher_round"        android:supportsRtl="true"        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

---------------------------------------


---------------------------------------

package com.example.lucainnocenti.jsontester;

import android.Manifest;
import android.content.pm.PackageManager;
import android.os.Environment;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.JsonWriter;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

import org.json.JSONException;
import org.json.JSONObject;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;


public class MainActivity extends AppCompatActivity {
    private int requestCode;
    private int grantResults[];
    private FileOutputStream out;
    private JsonWriter writer;
    private File card;
    private File file;

    @Override    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, requestCode);
        onRequestPermissionsResult(requestCode, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, grantResults);
        Button pulsante =(Button) findViewById(R.id.button);
        pulsante.setOnClickListener(new View.OnClickListener() {
            @Override            public void onClick(View view) {
                card = Environment.getExternalStorageDirectory();
                file = new File (card.getAbsolutePath(),"dati.json");
                try {
                    out = new FileOutputStream(file);
                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                }
                try {
                    writer = new JsonWriter(new OutputStreamWriter(out,"UTF-8"));
                } catch (UnsupportedEncodingException e) {
                    e.printStackTrace();
                }
                try {
                    writer.beginObject();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                try {
                    writer.name("nome").value("Luca");
                    writer.name("cognome").value("Innocenti");
                } catch (IOException e) {
                    e.printStackTrace();
                }

                try {
                    writer.endObject();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                try {
                    writer.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                ;


            }
        });
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
        switch (requestCode) {
            case 1: {

                // If request is cancelled, the result arrays are empty.                if (grantResults.length > 0
                        && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                    Log.d("permission", "granted");
                } else {


                    Toast.makeText(MainActivity.this, "Permission denied to read your External storage", Toast.LENGTH_SHORT).show();

                    onDestroy();
                }
                return;
            }
        }
    }
}

Bash ftp script

uno script bash per inviare dati in FTP
un paio di dettagli

1. per usare le wildcard si devono i comandi mdel ed mput
2. Per usare mput con la wildcard ci si deve prima spostare nella directory in cui sono contenuti i file mediante lcd perche' mput non permette di inserire il path completo ma solo il nome file
3. ftp -ni indica una sessione non interattiva e in modalita' autologin
4. quote serve ad inviare il contenuto della variabile al server remoto

------------------------------------------------------------------------------
#!/bin/sh
HOST="ftp.xxxxxxxxx.it"
USER="xxxxxxxx@aruba.it"
PASSWD="xxxxx"

ftp -ni $HOST<<END_SCRIPT
quote USER $USER
quote PASS $PASSWD
cd xxxxxx/yyyy/zzzzz/
mdel *
lcd /home/luca/
binary
mput *.ics
quit
END_SCRIPT
exit 0

SSH e disconnessione sessione

Succede piuttosto spesso di dover utilizzare una connessione remota in SSH e lanciare dei comandi (tipicamente delle query). Tipicamente quando si chiude una sessione ssh si uccidono anche tutti i processi che si erano aperti nella sezione. Per risolvere questo problema viene in aiuto il comando nohup

ssh luca@ip.ip.ip.ip "nohup /home/luca/comando> /dev/null 2>&1 &"

con la sintassi sopra riportata si lancia comando sia SSH senza che il suo processo venga chiuso al termine della sessione