所以我的项目包括一个光强度传感器和一个Android应用程序。我的Android Studio中有一个方法，我想重复运行，它的作用是从arduino接收数据。该方法从arduino接收数据并将其打印在logcat中。我见过asynctask或某些线程方法之类的东西。任何人都可以阐述或建议我可以尝试的东西吗？谢谢。
我的arduino代码：
#include <Wire.h>
#include <BH1750.h>
#include <SoftwareSerial.h>
BH1750 lightMeter;
SoftwareSerial BTSerial(0,1); //RX | TX
void setup(){
Serial.begin(9600);
lightMeter.begin();
BTSerial.begin(4800);
Serial.println("Running...");
}
void loop() {
uint16_t lux = lightMeter.readLightLevel();
Serial.print("Light: ");
Serial.print(lux);
Serial.println(" lx");
if (lux <= 0) {
BTSerial.print("#");
Serial.println("sending to android");
}
delay(1000);
}
我的android代码：
package com.example.android.cigarettebox;
import android.bluetooth.BluetoothServerSocket;
import android.os.Handler;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.bluetooth.BluetoothSocket;
import android.content.Intent;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import android.app.ProgressDialog;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.os.AsyncTask;
import java.io.IOException;
import java.io.InputStream;
import java.util.UUID;
import static com.example.android.cigarettebox.R.id.textView;
public class Menu extends ActionBarActivity {
Button btnOn, btnOff, btnDis,btnPage1, guides;
String address = null;
TextView testings;
private ProgressDialog progress;
BluetoothAdapter myBluetooth = null;
BluetoothSocket btSocket = null;
private boolean isBtConnected = false;
private InputStream inputStream;
//SPP UUID. Look for it
static final UUID myUUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
Intent newint = getIntent();
address = newint.getStringExtra(com.example.android.cigarettebox.DeviceList.EXTRA_ADDRESS); //receive the address of the bluetooth device
//view of the Menu
setContentView(R.layout.activity_menu);
//call the widgtes
btnOn = (Button)findViewById(R.id.button2);
btnOff = (Button)findViewById(R.id.button3);
btnDis = (Button)findViewById(R.id.button4);
btnPage1 = (Button) findViewById(R.id.button6);
guides = (Button) findViewById(R.id.guide);
testings = (TextView) findViewById(R.id.test);
new ConnectBT().execute(); //Call the class to connect
//commands to be sent to bluetooth
btnOn.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v)
{
turnOnLed(); //method to turn on
}
});
btnOff.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v)
{
turnOffLed(); //method to turn off
}
});
btnDis.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v)
{
Disconnect(); //close connection
}
});
btnPage1.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v)
{
// Make an intent to start next activity.
Intent intent = new Intent(v.getContext(), page1.class);
startActivity(intent);
}
});
guides.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v)
{
// Make an intent to start next activity.
Intent intent = new Intent(v.getContext(), page4.class);
startActivity(intent);
}
});
}
private void Disconnect()
{
if (btSocket!=null) //If the btSocket is busy
{
try
{
btSocket.close(); //close connection
}
catch (IOException e)
{ msg("Error");}
}
finish(); //return to the first layout
}
private void turnOffLed()
{
if (btSocket!=null)
{
try
{
btSocket.getOutputStream().write("TF".toString().getBytes());
}
catch (IOException e)
{
msg("Error");
}
}
}
private void turnOnLed()
{
if (btSocket!=null)
{
try
{
btSocket.getOutputStream().write("TO".toString().getBytes());
}
catch (IOException e)
{
msg("Error");
}
}
}
private void receives() {
try {
int bytes = 0, offset = 0;
byte[] buffer;
inputStream = btSocket.getInputStream();
bytes = inputStream.read();
buffer = new byte[bytes];
while (true)
{
bytes = inputStream.read(buffer, offset, buffer.length - offset);
offset += bytes;
if (bytes == -1 || offset >= buffer.length)
{
Log.d("MyBT", "message: " + new String(buffer));
testings.setText(new String(buffer));
break;
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
// fast way to call Toast
private void msg(String s)
{
Toast.makeText(getApplicationContext(),s,Toast.LENGTH_LONG).show();
}
private class ConnectBT extends AsyncTask<Void, Void, Void> // UI thread
{
private boolean ConnectSuccess = true; //if it's here, it's almost connected
@Override
protected void onPreExecute()
{
progress = ProgressDialog.show(Menu.this, "Connecting...", "Please wait!!!"); //show a progress dialog
}
@Override
protected Void doInBackground(Void... devices) //while the progress dialog is shown, the connection is done in background
{
try
{
if (btSocket == null || !isBtConnected)
{
myBluetooth = BluetoothAdapter.getDefaultAdapter();//get the mobile bluetooth device
BluetoothDevice dispositivo = myBluetooth.getRemoteDevice(address);//connects to the device's address and checks if it's available
btSocket = dispositivo.createInsecureRfcommSocketToServiceRecord(myUUID);//create a RFCOMM (SPP) connection
BluetoothAdapter.getDefaultAdapter().cancelDiscovery();
btSocket.connect();//start connection
}
}
catch (IOException e)
{
ConnectSuccess = false;//if the try failed, you can check the exception here
}
return null;
}
@Override
protected void onPostExecute(Void result) //after the doInBackground, it checks if everything went fine
{
super.onPostExecute(result);
if (!ConnectSuccess)
{
msg("Connection Failed. Try again.");
finish();
}
else
{
msg("Connected.");
isBtConnected = true;
}
progress.dismiss();
}
}
}
我想连续运行的方法：
private void receives() {
try {
int bytes = 0, offset = 0;
byte[] buffer;
inputStream = btSocket.getInputStream();
bytes = inputStream.read();
buffer = new byte[bytes];
while (true)
{
bytes = inputStream.read(buffer, offset, buffer.length - offset);
offset += bytes;
if (bytes == -1 || offset >= buffer.length)
{
Log.d("MyBT", "message: " + new String(buffer));
testings.setText(new String(buffer));
break;
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
stacktrace错误：
03-03 08:35:44.280 10854-12219/com.example.android.cigarettebox E/AndroidRuntime: FATAL EXCEPTION: Thread-7962
Process: com.example.android.cigarettebox, PID: 10854
java.lang.NullPointerException: Attempt to invoke virtual method 'java.io.InputStream android.bluetooth.BluetoothSocket.getInputStream()' on a null object reference
at com.example.android.cigarettebox.Menu$MyThread.run(Menu.java:254)
03-03 08:35:44.296 10854-12218/com.example.android.cigarettebox W/BluetoothAdapter: getBluetoothService() called with no BluetoothManagerCallback
03-03 08:35:44.676 10854-10861/com.example.android.cigarettebox W/art: Suspending all threads took: 6.314ms
03-03 08:35:44.820 10854-11128/com.example.android.cigarettebox D/OpenGLRenderer: endAllStagingAnimators on 0xb39e4e00 (ListView) with handle 0xa1108a60
03-03 08:35:45.260 10854-10854/com.example.android.cigarettebox E/WindowManager: android.view.WindowLeaked: Activity com.example.android.cigarettebox.Menu has leaked window com.android.internal.policy.PhoneWindow$DecorView{3cd38ff V.E...... R......D 0,0-1026,483} that was originally added here
at android.view.ViewRootImpl.<init>(ViewRootImpl.java:368)
at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:299)
at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:85)
at android.app.Dialog.show(Dialog.java:319)
at android.app.ProgressDialog.show(ProgressDialog.java:116)
at android.app.ProgressDialog.show(ProgressDialog.java:99)
at android.app.ProgressDialog.show(ProgressDialog.java:94)
at com.example.android.cigarettebox.Menu$ConnectBT.onPreExecute(Menu.java:200)
at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:604)
at android.os.AsyncTask.execute(AsyncTask.java:551)
at com.example.android.cigarettebox.Menu.onCreate(Menu.java:61)
at android.app.Activity.performCreate(Activity.java:6251)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
答案 0 :(得分：0)
您可以使用普通的Java thread进行操作。
class MyThread extends Thread {
Socket btSocket;
PrimeThread(Socket btSocket) {
this.btSocket = btSocket;
}
public void run() {
// your socket stuff
. . .
}
}