【Qt】Usb IO card

【目的】

• 使用Qt 透過廠商所提供的Dll 控制 USB IO card。

【硬體】

• Usb IO card
  http://www.icci.com.tw/web/MdFront?mdId=MD0000002307001371
• Devices Mananger
  
• Connect to LED on Bread board
  

【程式】

1. 使用 WinAPI方式載入Dll，並將 LED 點亮(送低電位)

   typedef DWORD (CALLBACK* OpenUSBDeviceFunc)(BYTE);
   typedef DWORD (CALLBACK* CloseDeviceFunc)(BYTE);
   typedef DWORD (CALLBACK* WriteIODataFunc)(BYTE,LPBYTE,DWORD,LPDWORD);
   
   HINSTANCE hDLL; // Handle to DLL
   OpenUSBDeviceFunc   lpfnOpenUSBDevice; // Function pointer
   CloseDeviceFunc     lpfnCloseDevice;
   WriteIODataFunc     lpfnWriteIOData;
   
   DWORD uReturnVal;
   
   hDLL = LoadLibrary(L"USBIODLL.dll");
   if (hDLL == NULL)
   {
       QMessageBox::information(this,tr("info"),tr("Load Dll Fail!"));
       goto exit;
   }
   lpfnOpenUSBDevice = (OpenUSBDeviceFunc)GetProcAddress(hDLL,"OpenUSBDevice");
   lpfnCloseDevice = (CloseDeviceFunc)GetProcAddress(hDLL,"CloseDevice");
   lpfnWriteIOData = (WriteIODataFunc)GetProcAddress(hDLL,"WriteIOData");
   if ((!lpfnOpenUSBDevice) || (!lpfnCloseDevice) || (!lpfnWriteIOData))
   {
     // handle the error
     QMessageBox::information(this,tr("info"),tr("GetProcAddress Fail!"));
     goto free;
   }
   
   // call the function
   uReturnVal = lpfnOpenUSBDevice(0);
   if (uReturnVal) {
       QMessageBox::information(this,tr("info"),tr("Open Fail!"));
       goto free;
   }
   {
   BYTE  pSrc[4];
   DWORD dwRet;
   WORD  wData = 0x0;
   pSrc[0] = (BYTE)wData & 0x00FF;
   pSrc[1] = (BYTE)((wData & 0xFF00) >>8);
   uReturnVal = lpfnWriteIOData(0, pSrc, 2, &dwRet);
   if (uReturnVal) {
     QMessageBox::information(this,tr("info"),tr("Write Fail!"));
     goto free;
   }
   }
   uReturnVal = lpfnCloseDevice(0);
   if (uReturnVal) {
     QMessageBox::information(this,tr("info"),tr("Close Fail!"));
     goto free;
   }
   free:
   FreeLibrary(hDLL);
   exit:
   if (uReturnVal) {
       // TODO:
       //ShowErrorCode();
   }

2. 透過QLibrary方式（省略）

【研究】

• 只看到提供Windows 系列的 Driver，不確定 Mac/Linux 是否能用。
• AVR 系列好像有可以直接走 USB Protocol 和 PC 對連，可能會比目前所用的架構簡單。
• 硬體多加一棵 USB2UART 走 RS232 方式可能會比較能達到跨平台要求。

【參考】

• USB 8051/AVR programmer
  http://www.8051projects.info/blogs/post/USB-8051AVR-programmer.aspx
• USB DIY 講座 （六） --- USB I/O
  http://chamberplus.myweb.hinet.net/usb.htm