最近在尝试写一个安卓版的无人机地面站，参考了DroidPlanner的代码，发现了一个很好用的串口通信组件usb-serial-for-android，免root权限，不需要NDK，不过只支持Android 3.1+。

github地址：

 

关于用法README.md中已经介绍得很详尽了，可以简单归结为以下几点：

1. 把usb-serial-for-android复制到工程中，Eclipse和Android Studio的处理方式各不相同，具体步骤可参考；

2. 复制到工程的res/xml目录（没有则自行新建）；

3. 配置AndroidManifest.xml；

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4. 编写代码。

1 // Find all available drivers from attached devices. 2 UsbManager manager = (UsbManager) getSystemService(Context.USB_SERVICE); 3 List
     
       availableDrivers = UsbSerialProber.getDefaultProber().findAllDrivers(manager); 4 if (availableDrivers.isEmpty()) { 5   return; 6 } 7  8 // Open a connection to the first available driver. 9 UsbSerialDriver driver = availableDrivers.get(0);10 UsbDeviceConnection connection = manager.openDevice(driver.getDevice());11 if (connection == null) {12   // You probably need to call UsbManager.requestPermission(driver.getDevice(), ..)13   return;14 }15 16 // Read some data! Most have just one port (port 0).17 UsbSerialPort port = driver.getPorts().get(0);18 try {19   port.open(connection);20   port.setParameters(115200, 8, UsbSerialPort.STOPBITS_1, UsbSerialPort.PARITY_NONE);21 22   byte buffer[] = new byte[16];23   int numBytesRead = port.read(buffer, 1000);24   Log.d(TAG, "Read " + numBytesRead + " bytes.");25 } catch (IOException e) {26   // Deal with error.27 } finally {28   port.close();29 }
     

 

以下是我修改过的简单的例子（基于Android Studio 2.2.3）。

 

MainActivity.java

1 package com.stshdz.drone.shdrone;  2   3 import android.content.Context;  4 import android.hardware.usb.UsbDeviceConnection;  5 import android.hardware.usb.UsbManager;  6 import android.os.Handler;  7 import android.os.Message;  8 import android.support.v7.app.AppCompatActivity;  9 import android.os.Bundle; 10 import android.view.View; 11 import android.widget.TextView; 12  13 import com.hoho.android.usbserial.driver.UsbSerialDriver; 14 import com.hoho.android.usbserial.driver.UsbSerialPort; 15 import com.hoho.android.usbserial.driver.UsbSerialProber; 16  17 import java.io.IOException; 18 import java.util.List; 19  20 public class MainActivity extends AppCompatActivity { 21     UsbSerialPort port = null; 22  23     class MyHandler extends Handler { 24         @Override 25         public void handleMessage(Message msg) { 26             switch (msg.what) { 27                 case 0x11: 28                     TextView tv_display = (TextView)findViewById(R.id.tv_display); 29                     Bundle bundle = msg.getData(); 30                     tv_display.setText(tv_display.getText() + bundle.getString("text")); 31                     break; 32                 default: 33                     break; 34             } 35         } 36     } 37  38  39     private MyHandler myHandler = new MyHandler(); 40  41     @Override 42     protected void onCreate(Bundle savedInstanceState) { 43         super.onCreate(savedInstanceState); 44         getSupportActionBar().hide(); 45         setContentView(R.layout.activity_main); 46  47         findViewById(R.id.btn_send).setOnClickListener(new View.OnClickListener() { 48             @Override 49             public void onClick(View v) { 50                 try { 51                     if(port != null){ 52                         port.write("Hello\r\n".getBytes(), 1000); 53                     } 54                 } catch (IOException e) { 55                     e.printStackTrace(); 56                 } 57             } 58         }); 59  60         new Thread(new Runnable() { 61             @Override 62             public void run() { 63  64                 // Find all available drivers from attached devices. 65                 UsbManager manager = (UsbManager) getSystemService(Context.USB_SERVICE); 66                 List
     
       availableDrivers = UsbSerialProber.getDefaultProber().findAllDrivers(manager); 67                 if (availableDrivers.isEmpty()) { 68                     return; 69                 } 70  71                 // Open a connection to the first available driver. 72                 UsbSerialDriver driver = availableDrivers.get(0); 73                 UsbDeviceConnection connection = manager.openDevice(driver.getDevice()); 74                 if (connection == null) { 75                     // You probably need to call UsbManager.requestPermission(driver.getDevice(), ..) 76                     return; 77                 } 78  79                 // Read some data! Most have just one port (port 0). 80                 port = driver.getPorts().get(0); 81                 try { 82                     port.open(connection); 83                     port.setParameters(115200, 8, UsbSerialPort.STOPBITS_1, UsbSerialPort.PARITY_NONE); 84  85                     while(true) { 86                         byte buffer[] = new byte[16]; 87                         int numBytesRead = port.read(buffer, 1000); 88  89                         if(numBytesRead > 0){ 90                             Message message = new Message(); 91                             message.what = 0x11; 92                             Bundle bundle = new Bundle(); 93                             bundle.putString("text", new String(buffer, "UTF-8")); 94                             message.setData(bundle); 95                             myHandler.sendMessage(message); 96                         } 97                     } 98  99                 } catch (IOException e) {100                     // Deal with error.101                 } finally {102                     try {103                         port.close();104                     } catch (IOException e) {105                         e.printStackTrace();106                     }107                 }108             }109         }).start();110     }111 }
     

 

 

activity_main.xml

 

xml/device_filter.xml

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AndroidManifest.xml

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Android设备通过OTG数据线连接USB转TTL模块，模块的TX与RX引脚短接（自发自收），点击“SEND”即可看到效果。