要连接到ELM327/OBD2设备,你可以使用Android的蓝牙API。以下是一个基本的示例代码,演示如何连接到设备并发送和接收数据。
首先,确保你的Android设备已经配对了ELM327/OBD2设备。然后,创建一个新的Android项目,添加以下代码:
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import androidx.appcompat.app.AppCompatActivity;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.UUID;
public class MainActivity extends AppCompatActivity {
private static final String TAG = "MainActivity";
private static final int REQUEST_ENABLE_BT = 1;
private static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
private BluetoothAdapter mBluetoothAdapter;
private BluetoothDevice mDevice;
private BluetoothSocket mSocket;
private InputStream mInputStream;
private OutputStream mOutputStream;
private TextView mTextView;
private Button mBtnConnect;
private Handler mHandler;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mTextView = findViewById(R.id.text_view);
mBtnConnect = findViewById(R.id.btn_connect);
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if (mBluetoothAdapter == null) {
// 设备不支持蓝牙
Log.e(TAG, "Device does not support Bluetooth");
return;
}
if (!mBluetoothAdapter.isEnabled()) {
// 请求打开蓝牙
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
}
mBtnConnect.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
connectToDevice();
}
});
mHandler = new Handler();
}
private void connectToDevice() {
// 获取已配对的设备列表
Set pairedDevices = mBluetoothAdapter.getBondedDevices();
if (pairedDevices.size() > 0) {
for (BluetoothDevice device : pairedDevices) {
if (device.getName().contains("ELM327")) {
mDevice = device;
break;
}
}
}
if (mDevice == null) {
// 没有找到匹配的设备
Log.e(TAG, "No matching device found");
return;
}
try {
mSocket = mDevice.createRfcommSocketToServiceRecord(MY_UUID);
mSocket.connect();
mInputStream = mSocket.getInputStream();
mOutputStream = mSocket.getOutputStream();
// 在新的线程中监听输入流
new Thread(new Runnable() {
@Override
public void run() {
byte[] buffer = new byte[1024];
int bytes;
while (true) {
try {
bytes = mInputStream.read(buffer);
final String response = new String(buffer, 0, bytes);
mHandler.post(new Runnable() {
@Override
public void run() {
// 处理接收到的数据
// 在这里更新UI或进行其他操作
mTextView.setText(response);
}
});
} catch (IOException e) {
Log.e(TAG, "Error reading from InputStream", e);
break;
}
}
}
}).start();
} catch (IOException e) {
Log.e(TAG, "Error connecting to device", e);
}
}
private void sendData(String data) {
try {
mOutputStream.write(data.getBytes());
} catch (IOException e) {
Log.e(TAG, "Error sending data", e);
}
}
@Override
protected void onDestroy() {
super.onDestroy();
// 关闭连接和流
try {
if (mOutputStream != null) {
mOutputStream.close();
}
if (mInputStream != null) {
mInputStream.close();
}
if (mSocket != null) {
mSocket.close();
}
} catch (IOException e) {
Log