1
I built an app to receive data from a sensor connected to the Antarctic over the Internet using a Shield Ethernet. For this I took the result of the page and separated only the sensor measure on android.
I managed to get the result of the page but only the pressing of a button. How it would be for it to update automatically?
Main class
package com.example.appethernetsensor_;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import java.io.IOException;
import android.app.Activity;
import android.content.Context;
import android.graphics.Color;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity {
Button btnAtualizar;
TextView medidaSensor;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnAtualizar = (Button)findViewById(R.id.button1);
medidaSensor= (TextView)findViewById(R.id.textViewMedida);
btnAtualizar.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String stringUrl = "http://192.168.25.85/";
//Verifica se há alguma conectividade de rede
ConnectivityManager connMgr = (ConnectivityManager)
getSystemService(Context.CONNECTIVITY_SERVICE);
//Qual o tipo da rede, se é wifi, rede movel ...
NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();
//Se tiver conexão ...
if (networkInfo != null && networkInfo.isConnected()) {
new DownloadWebpageTask().execute(stringUrl);
} else {
Toast.makeText(getApplicationContext(), "Nenhma conexão disponível", Toast.LENGTH_LONG).show();
}
}
});
}
private class DownloadWebpageTask extends AsyncTask<String, Void, String> {
@Override
protected String doInBackground(String... urls) {
// params comes from the execute() call: params[0] is the url.
try {
Conexao conexao = new Conexao();
return conexao.downloadUrl(urls[0]);
} catch (IOException e) {
return "URL inválida";
}
}
protected void onPostExecute(String result) {
StringBuffer medida = new StringBuffer(result);
replaceAll(medida, "<html>Sensor Ultrasonico : <b>", "");
replaceAll(medida, "</b></html>", "");
medidaSensor.setText(medida);
}
}
/*
* protected void onPostExecute(String result) {
StringBuffer medida = new StringBuffer(result);
replaceAll(medida, "<html>Sensor Ultrasonico : <b>", "");
replaceAll(medida, " cm", "");
replaceAll(medida, "</b></html>", "");
String s = medida.toString();//Converte a stringbuffer final para string
int i = Integer.parseInt(s);//Converte a string para inteiro
if(i>=0){
medidaSensor.setText(i + " cm");
}else{
medidaSensor.setText("Um momento...");
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
*/
}
Connection class
package com.example.appethernetsensor_;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;
public class Conexao {
// Given a URL, establishes an HttpUrlConnection and retrieves
// the web page content as a InputStream, which it returns as
// a string.
public String downloadUrl(String myurl) throws IOException {
InputStream is = null;
// Only display the first 500 characters of the retrieved
// web page content.
int len = 5000;
try {
URL url = new URL(myurl);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout(10000 /* milliseconds */);
conn.setConnectTimeout(15000 /* milliseconds */);
conn.setRequestMethod("GET");
conn.setDoInput(true);
// Starts the query
conn.connect();
is = conn.getInputStream();
// Convert the InputStream into a string
String contentAsString = readIt(is, len);
return contentAsString;
// Makes sure that the InputStream is closed after the app is
// finished using it.
} finally {
if (is != null) {
is.close();
}
}
}
// Reads an InputStream and converts it to a String.
public String readIt(InputStream stream, int len) throws IOException, UnsupportedEncodingException {
Reader reader = null;
reader = new InputStreamReader(stream, "UTF-8");
char[] buffer = new char[len];
reader.read(buffer);
return new String(buffer);
}
}
Code Arduin
#include <Ultrasonic.h>
#include <SPI.h>
#include <Ethernet.h>
//Define os parametros para o sensor ultrasonico HC-SR04
#define PINO_TRIGGER 6 //Porta ligada ao pino Trigger do sensor
#define PINO_ECHO 7 //Porta ligada ao pino Echo do sensor
//Inicializa o sensor ultrasonico
Ultrasonic ultrasonic(PINO_TRIGGER, PINO_ECHO);
//Definicoes de IP, mascara de rede e gateway
byte mac[] = {
0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED
};
IPAddress ip(192, 168, 25, 85); //Define o endereco IP
IPAddress gateway(192, 168, 25, 1); //Define o gateway
IPAddress subnet(255, 255, 255, 0); //Define a máscara de rede
//Inicializa o servidor web na porta 80
EthernetServer server(80);
void setup()
{
//Inicializa a interface de rede
Ethernet.begin(mac, ip, gateway, subnet);
server.begin();
}
void loop() {
float cmMsec;
long microsec = ultrasonic.timing();
//Le e armazena as informacoes do sensor ultrasonico
cmMsec = ultrasonic.convert(microsec, Ultrasonic::CM);
//Aguarda conexao do browser
EthernetClient client = server.available();
if (client) {
Serial.println("new client");
// an http request ends with a blank line
boolean currentLineIsBlank = true;
while (client.connected()) {
if (client.available()) {
char c = client.read();
Serial.write(c);
// if you've gotten to the end of the line (received a newline
// character) and the line is blank, the http request has ended,
// so you can send a reply
if (c == 'n' && currentLineIsBlank) {
// send a standard http response header
client.println("HTTP/1.1 200 OK");
client.println("Content-Type: text/html");
client.println("Connection: close");
client.println("Refresh: 2"); //Recarrega a pagina a cada 2seg
client.println();
client.print("<html>");
//Mostra as informacoes lidas pelo sensor ultrasonico
client.print("Sensor Ultrasonico : ");
client.print("<b>");
client.print(cmMsec);
client.print("000");
client.print(" cm");
client.println("</b></html>");
break;
}
if (c == 'n') {
// you're starting a new line
currentLineIsBlank = true;
}
else if (c != 'r') {
// you've gotten a character on the current line
currentLineIsBlank = false;
}
}
}
// give the web browser time to receive the data
delay(1);
// close the connection:
client.stop();
}
}