How to detect USB device in Android tablet which acts as USB Host?
Solution 1
I had the same problem and I suspect that the host feature may be disabled on your tablet so I suggest that you check.
The following post is probably the best reference to look at as it is concise Android USB host and hidden devices
You should be able to check if the file android.hardware.usb.host.xml exist with the adb shell
Solution 2
mmmm...
device = deviceList.get("deviceName");
i think u must insert the name of your device instead of "deviceName".
Allen
Updated on June 14, 2022Comments
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Allen almost 2 years
I have tried developing a sample app with the help of the code from Developers.android.com.
My code looks like this
public class MainActivity extends Activity { UsbManager manager; HashMap<String, UsbDevice> deviceList; Button scanButton; UsbDevice device; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); scanButton = (Button)this.findViewById(R.id.button1); scanButton.setOnClickListener(new OnClickListener () { public void onClick(View v) { checkForDevices (); } }); } @Override public void onResume () { super.onResume(); checkForDevices (); } @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.activity_main, menu); return true; } protected void checkForDevices () { manager = (UsbManager) getSystemService(Context.USB_SERVICE); deviceList = manager.getDeviceList(); device = deviceList.get("deviceName"); //Collection<UsbDevice> devices = deviceList.values(); if (device != null) Toast.makeText(this, "Device Found", Toast.LENGTH_LONG).show(); else Toast.makeText(this, "Device NOT Found", Toast.LENGTH_LONG).show(); } }
When I run this code with a USB device connected, I always get the Toast as "Device NOT Found".
I want my app to detect the USB device and Read input and Write Output in USB Host Mode.
Is there any way to detect an USB device in our App?