android - android中的USB接口(interface)

Question

我对我的设备进行了 root 操作并在主机模式下工作。我可以检测到连接到我的选项卡的 USB 设备，但是我有两个问题。

1) 我尝试使用来显示我的设备名称 device.getDeviceName();但它显示类似/dev/usb/002/002我需要获取 usb 设备名称的制造商名称。我认为它在附件模式下可用，但我需要在主机模式下获取制造商名称。

2) 我需要将一些数据从我的应用程序传输到 android 中的 usb 端口。我可以检测到设备，但请帮助将一些数据或文件从我的 Android 应用程序传输到连接到 USB 端口的大容量存储设备。

Answer 1

您可能实际上需要阅读原始 USB 描述符以获取您想要的数据。这是我为自己的目的编写的基本 USB 设备发现程序。请注意，我正在寻找特定设备(Dajac Easy I/O 1000 数据采集系统)，但您可以应用相同的原理。我确实向您展示了如何获取您正在寻找的数据。

先上代码。我的包是usbtest3，文件是MainActivity.java:

package com.hotspotoffice.usbtest3;

// David Schofield, Hotspot Office, LLC., Pittsburgh, PA.
// Donations via PayPal always welcome! schofield (dot) david (at) verizon.net

import java.io.UnsupportedEncodingException;
import java.util.HashMap;
import java.util.Iterator;
import android.os.Bundle;
import android.app.Activity;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.view.View;
import android.view.Menu;
import android.widget.Button;
import android.widget.TextView;
import android.hardware.usb.UsbConstants;
import android.hardware.usb.UsbManager;
import android.hardware.usb.UsbDevice;
import android.hardware.usb.UsbDeviceConnection;
import android.hardware.usb.UsbInterface;


public class MainActivity extends Activity {

    protected static final int STD_USB_REQUEST_GET_DESCRIPTOR = 0x06;
    // http://libusb.sourceforge.net/api-1.0/group__desc.html
    protected static final int LIBUSB_DT_STRING = 0x03;
    private static final String ACTION_USB_PERMISSION = "com.android.example.USB_PERMISSION";

    private Button btnDiscover;
    private TextView txtInfo;
    private PendingIntent mPermissionIntent; 

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

        btnDiscover=(Button)findViewById(R.id.btnDiscover);
        txtInfo=(TextView)findViewById(R.id.txtInfo);

        mPermissionIntent = PendingIntent.getBroadcast(this, 0, new Intent(ACTION_USB_PERMISSION), 0);
        IntentFilter filter = new IntentFilter(ACTION_USB_PERMISSION);
        registerReceiver(mUsbReceiver, filter);

        btnDiscover.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // txtInfo.setText("Button has been Pressed for "+(++i)+" Times.");

                UsbManager manager = (UsbManager)getSystemService(Context.USB_SERVICE);

                HashMap<String, UsbDevice> deviceList = manager.getDeviceList();
                Iterator<UsbDevice> deviceIterator = deviceList.values().iterator();
                while(deviceIterator.hasNext()){
                    UsbDevice device = deviceIterator.next();

                    manager.requestPermission(device, mPermissionIntent);

                    txtInfo.append("Model:" + device.getDeviceName() + "\n");  
                    txtInfo.append("DeviceID:" + device.getDeviceId() + "\n");
                    txtInfo.append("Vendor:" + device.getVendorId() + "\n");
                    txtInfo.append("Product:" + device.getProductId() + "\n");
                    txtInfo.append("Class:" + device.getDeviceClass() + "\n");
                    txtInfo.append("Subclass:" + device.getDeviceSubclass() + "\n");
                    txtInfo.append("Protocol:" + device.getDeviceProtocol() + "\n");

                    UsbInterface intf = device.getInterface(0);
                    int epc = 0;
                    epc = intf.getEndpointCount();
                    txtInfo.append("Endpoints:" + epc + "\n");

                    txtInfo.append("Permission:" + Boolean.toString(manager.hasPermission(device))  + "\n");

                    UsbDeviceConnection connection = manager.openDevice(device);
                    if(null==connection){
                        txtInfo.append("(unable to establish connection)\n");
                    } else {

                        // Claims exclusive access to a UsbInterface. 
                        // This must be done before sending or receiving data on 
                        // any UsbEndpoints belonging to the interface.
                        connection.claimInterface(intf, true);

                        // getRawDescriptors can be used to access descriptors 
                        // not supported directly via the higher level APIs, 
                        // like getting the manufacturer and product names.
                        // because it returns bytes, you can get a variety of
                        // different data types.
                        byte[] rawDescs = connection.getRawDescriptors();
                        String manufacturer = "", product = "";

                        try
                        {
                            byte[] buffer = new byte[255];
                            int idxMan = rawDescs[14];
                            int idxPrd = rawDescs[15];

                            int rdo = connection.controlTransfer(UsbConstants.USB_DIR_IN
                                    | UsbConstants.USB_TYPE_STANDARD, STD_USB_REQUEST_GET_DESCRIPTOR,
                                    (LIBUSB_DT_STRING << 8) | idxMan, 0, buffer, 0xFF, 0);
                            manufacturer = new String(buffer, 2, rdo - 2, "UTF-16LE");

                            rdo = connection.controlTransfer(UsbConstants.USB_DIR_IN
                                            | UsbConstants.USB_TYPE_STANDARD, STD_USB_REQUEST_GET_DESCRIPTOR,
                                    (LIBUSB_DT_STRING << 8) | idxPrd, 0, buffer, 0xFF, 0);
                            product = new String(buffer, 2, rdo - 2, "UTF-16LE");

                        } catch (UnsupportedEncodingException e)
                        {
                        e.printStackTrace();
                        }

                        txtInfo.append("Manufacturer:" + manufacturer + "\n");                      
                        txtInfo.append("Product:" + product + "\n");                        
                        txtInfo.append("Serial#:" + connection.getSerial() + "\n");                     
                    }

                    txtInfo.append("------------------------------------\n");                   
                }               

            }
        });

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }

    private final BroadcastReceiver mUsbReceiver = new BroadcastReceiver() {

        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            if (ACTION_USB_PERMISSION.equals(action)) {
                synchronized (this) {
                    UsbDevice device = (UsbDevice)intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);

                    if (intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
                        if(device != null){
                          //call method to set up device communication
                       }
                    } 
                    else {
                        txtInfo.append("permission denied for device " + device);
                    }
                }
            }
        }
    };

}

我的 list 文件包含 USB 主机设备支持的 Intent 和要求:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.hotspotoffice.usbtest3"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-feature android:name="android.hardware.usb.host" />

    <uses-sdk
        android:minSdkVersion="15"
        android:targetSdkVersion="15" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >

        <activity
            android:name="com.hotspotoffice.usbtest3.MainActivity"
            android:label="@string/app_name" >

            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>

            <intent-filter>
                <action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" />
            </intent-filter>

            <meta-data android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED"
                android:resource="@xml/device_filter" />

        </activity>
    </application>

</manifest>

最后，您需要一个设备过滤器。这位于\res\xml\device_filter.xml 下请注意，我必须自己在\res 下创建 xml 文件夹。

<?xml version="1.0" encoding="utf-8"?>

<resources>
    <usb-device vendor-id="7635" product-id="1" class="255" subclass="255" protocol="0" />
</resources>

请注意，所有字段都必须是十进制，而不是十六进制。您需要从您自己的设备中替换您自己的供应商、产品、类和子类值。您可以使用“USB Host View”或“USB Device Info”等程序来发现这些值。 (从 Play 商店免费下载。)

最后，这是我在 Activity_Main.xml 中定义用户界面的方式
您至少需要 Discover 按钮和用于输出的 TextMultiline。 (忽略 Init 和 On/Off 按钮。)

顺便说一句，我使用的是 10"Toshiba Thrive 平板电脑，所以 YMMV。

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >

    <EditText
        android:id="@+id/txtInfo"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/btnDiscover"
        android:layout_alignRight="@+id/textView1"
        android:layout_centerVertical="true"
        android:ems="10"
        android:inputType="textMultiLine"
        android:maxLines="50"
        android:minLines="20"
        android:minWidth="400dp" >

        <requestFocus />
    </EditText>

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/btnToggleDIO"
        android:layout_marginLeft="192dp"
        android:layout_toRightOf="@+id/btnDiscover"
        android:text="@string/lblDIO"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <Button
        android:id="@+id/btnDiscover"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/btnInit"
        android:layout_alignBottom="@+id/btnInit"
        android:layout_alignParentLeft="true"
        android:layout_marginLeft="73dp"
        android:text="@string/strDiscover" />

    <ToggleButton
        android:id="@+id/btnToggleDIO"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/btnInit"
        android:layout_alignBottom="@+id/btnInit"
        android:layout_alignLeft="@+id/textView1"
        android:text="@string/strIOState" />

    <Button
        android:id="@+id/btnInit"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/txtInfo"
        android:layout_marginBottom="29dp"
        android:layout_marginLeft="48dp"
        android:layout_toRightOf="@+id/btnDiscover"
        android:text="@string/strInit" />

</RelativeLayout>

当我运行我的程序并插入我的设备时，它会请求我的连接许可，然后我说“确定”。然后我点击“发现”，它告诉我制造商是“Dajac Inc.”。产品是“EIO1000”，序列号是“0000004B”。

祝你好运；你可以相信我，但只有站在别人的肩膀上(我自己付出了很多汗水)我才能看到这么远。转发吧!-大卫