Android串口如何接收數(shù)據(jù)

小樊
138
2024-08-03 04:45:20

要在Android設(shè)備上接收串口數(shù)據(jù)，可以使用Android提供的SerialPort類或第三方庫(kù)來(lái)實(shí)現(xiàn)串口通信。以下是一個(gè)簡(jiǎn)單的示例代碼，演示如何在Android設(shè)備上接收串口數(shù)據(jù)：

  1. 首先，添加必要的權(quán)限到AndroidManifest.xml文件中：
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />
<uses-permission android:name="android.permission.READ_PHONE_STATE" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WRITE_SETTINGS" />
  1. 創(chuàng)建一個(gè)SerialPort類來(lái)處理串口通信：
public class SerialPort {
    private static final String TAG = SerialPort.class.getSimpleName();

    private FileDescriptor mFd;
    private FileInputStream mFileInputStream;
    private FileOutputStream mFileOutputStream;

    public SerialPort(File device, int baudrate, int flags) throws SecurityException, IOException {
        mFd = open(device.getAbsolutePath(), baudrate, flags);
        if (mFd == null) {
            Log.e(TAG, "native open returns null");
            throw new IOException();
        }
        mFileInputStream = new FileInputStream(mFd);
        mFileOutputStream = new FileOutputStream(mFd);
    }

    public InputStream getInputStream() {
        return mFileInputStream;
    }

    public OutputStream getOutputStream() {
        return mFileOutputStream;
    }

    private native static FileDescriptor open(String path, int baudrate, int flags);

    public native void close();

    static {
        System.loadLibrary("serial_port");
    }
}
  1. 在MainActivity中實(shí)現(xiàn)串口數(shù)據(jù)接收：
public class MainActivity extends AppCompatActivity {
    private SerialPort mSerialPort;
    private InputStream mInputStream;
    private TextView mTextView;

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

        mTextView = findViewById(R.id.text_view);

        try {
            mSerialPort = new SerialPort(new File("/dev/ttyUSB0"), 9600, 0);
            mInputStream = mSerialPort.getInputStream();

            new Thread(new Runnable() {
                @Override
                public void run() {
                    while (true) {
                        try {
                            byte[] buffer = new byte[1024];
                            int size = mInputStream.read(buffer);
                            if (size > 0) {
                                final String data = new String(buffer, 0, size);
                                runOnUiThread(new Runnable() {
                                    @Override
                                    public void run() {
                                        mTextView.setText(data);
                                    }
                                });
                            }
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                }
            }).start();
        } catch (SecurityException | IOException e) {
            e.printStackTrace();
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (mSerialPort != null) {
            mSerialPort.close();
        }
    }
}

在上面的示例中，我們創(chuàng)建了一個(gè)SerialPort類來(lái)處理串口通信，并在MainActivity中實(shí)例化該類來(lái)接收串口數(shù)據(jù)。我們?cè)谝粋€(gè)單獨(dú)的線程中讀取串口數(shù)據(jù)并在UI線程中更新TextView來(lái)顯示接收到的數(shù)據(jù)。最后，在Activity銷毀時(shí)關(guān)閉串口連接。請(qǐng)注意，上面的代碼僅供參考，實(shí)際項(xiàng)目中需要根據(jù)具體需求進(jìn)行修改和優(yōu)化。

0 踩