java - USB主机传输Android与Spartan 6 FPGA

Question

因此，我需要在 Android 中编写一个应用程序，该应用程序必须能够读取来自 FPGA SPARTAN 6 的数据。

我的应用程序能够识别 USB 何时连接，并且可以获取有关接口(interface)和该接口(interface)上的端点的信息。但随后它需要读取某人在按下按钮时发送的数据，这就是应用程序失败的时候。

我的代码如下:

package com.example.usb;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.hardware.usb.*;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.widget.TextView;

public class MainActivity extends Activity 
{
 private UsbManager usbManager;
private UsbDevice device;
private TextView tv;

Handler handler = new Handler()
{
    public  void handleMessage(Message m)
    {
        Integer datos = (Integer)m.obj;
        tv.setText(datos + "\n");
    }
};


@Override
protected void onCreate(Bundle savedInstanceState) 
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    tv = (TextView)findViewById(R.id.tv);
    usbManager = (UsbManager)getSystemService(Context.USB_SERVICE); 
}

@Override
protected void onResume() 
{
    super.onResume();
    Intent intent = getIntent();
    String action = intent.getAction();
    if (action.equals(UsbManager.ACTION_USB_DEVICE_ATTACHED))
    {
        //conectar dispositivo
        device = (UsbDevice)intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
        //muestraDatos(device);
        UsbInterface intf = device.getInterface(1);
        UsbEndpoint epIN = getIN(device);
        //tv.setText(epIN.getDirection() + " " + epIN.getType());
        UsbDeviceConnection connection = usbManager.openDevice(device);
        new Thread(new Read(connection,intf,epIN,handler)).start();
    }
}

private UsbEndpoint getIN(UsbDevice device)
{
    UsbInterface intf = device.getInterface(1);
    UsbEndpoint ep = null;
    int numep = intf.getEndpointCount();
    for (int i = 0 ; i < numep ; i++)
    {
        UsbEndpoint aux = intf.getEndpoint(i);
        if (aux.getDirection() == UsbConstants.USB_DIR_IN && aux.getType() ==   UsbConstants.USB_ENDPOINT_XFER_BULK)
        {
            ep = aux;
        }
    }
    return ep;
}

线程读取(应该从 FPGA 读取)是:

package com.example.usb;

import android.hardware.usb.UsbDeviceConnection;
import android.hardware.usb.UsbEndpoint;
import android.hardware.usb.UsbInterface;
import android.os.Handler;
import android.os.Message;

public class Read implements Runnable 
{
 private UsbDeviceConnection connection;
 private UsbEndpoint epIN;
private Handler handler;
private UsbInterface intf;

   public Read(UsbDeviceConnection connection,UsbInterface intf,UsbEndpoint epIN,Handler handler)
{
     this.connection = connection;
     this.epIN = epIN;
     this.handler = handler;
     this.intf = intf;
 }

public void run()
{
    byte datos[] = new byte[50];
    int read_data = 0;

    if (connection.claimInterface(intf,true))
    {
        /*Message sms = new Message();
        sms.obj = "Success caliming interface: " + intf.getEndpointCount();
        handler.sendMessage(sms);*/
        //connection.controlTransfer(0x00000080, 0x03, 0x4138, 0, null, 0, 0);


        while (true)
        {
            try
            {
                Thread.sleep(500);
            }
            catch(InterruptedException e){}
            read_data = connection.bulkTransfer(epIN, datos, datos.length, 100);
            datos = new byte[50];
            //if (read_data > -1)
            //{
                Message sms = new Message();
                sms.obj = read_data;
                handler.sendMessage(sms);
            //}
        }
    }
    else
    {
        Message sms = new Message();
        sms.obj = "Fail claiming interface ";
        handler.sendMessage(sms);
    }



}

}

我的目标只是显示使用函数bulktransfer读取的字节数，但它没有显示任何内容。另外，我相信我必须使用 controlTransfer 函数，但官方文档没有解释有关该函数的任何内容，它只是一个黑暗的引用。我看过这样的帖子Android 4.0.3. USB Host - sending data via controlTransfer还有这个Serial to USB Android application with health device但不太清楚函数中每个参数的含义是什么。有人知道我做错了什么和/或对 controTransfer 函数有一个很好的解释吗？

Answer 1

那么，你需要有一个USB转串口的接口(interface)设备来连接你的Android主机，在FPGA端，它是一个普通的串口。

您可以在以下页面之一查看示例:

http://www.fpga4fun.com/SerialInterface.html或者 http://www.bealto.com/fpga-uart.html