title: Android to PC USB Read/Write
body: <p>I have a program on PC taking in  string input from USB ( old program) I have a Android (4.X) tablet which needs to provide string input on USB to the program running on PC.
  When I used the sample code on Android, following code gives empty hashmap. The PC( tried on 32 bit XP and 64 bit Windows 7) has Android driver.</p>
  
  <pre><code>    mManager = (UsbManager)getSystemService(Context.USB_SERVICE);
      HashMap&lt;String, UsbDevice&gt; devices =  mManager.getDeviceList();
  </code></pre>
  
  <p>Any real working code example talking to PC over USB will help, pl. also point out if any driver etc. needed on Android to talk to PC. </p>
  
  <p>I have tried both the Accessory mode and the host mode( just in case)</p>