Search UsbInterface and UsbEndpoint, of USB_ENDPOINT_XFER_BULK type, with both USB_DIR_OUT and USB_DIR_IN

This example scan USB devices in USB Host mode, search for any UsbInterface and UsbEndpoint, of USB_ENDPOINT_XFER_BULK type, with both USB_DIR_OUT and USB_DIR_IN.

Search UsbInterface and UsbEndpoint automatically
Search UsbInterface and UsbEndpoint
Modify MainActivity.java in "Use intent filter to detect a specified USB device and auto start application", implement searchEndPoint() and remove un-necessary function.
package com.example.androidusbhost;

import java.io.UnsupportedEncodingException;
import java.util.HashMap;
import java.util.Iterator;

import android.hardware.usb.UsbConstants;
import android.hardware.usb.UsbDevice;
import android.hardware.usb.UsbDeviceConnection;
import android.hardware.usb.UsbEndpoint;
import android.hardware.usb.UsbInterface;
import android.hardware.usb.UsbManager;
import android.os.Bundle;
import android.widget.TextView;
import android.widget.Toast;
import android.app.Activity;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;

public class MainActivity extends Activity {

TextView textInfo;
TextView textSearchedEndpoint;

TextView textDeviceName;
TextView textStatus;

private static final int targetVendorID= 9025;
private static final int targetProductID = 32828;
UsbDevice deviceFound = null;
UsbInterface usbInterfaceFound = null;
UsbEndpoint endpointIn = null;
UsbEndpoint endpointOut = null;

private static final String ACTION_USB_PERMISSION =
"com.android.example.USB_PERMISSION";
PendingIntent mPermissionIntent;

UsbInterface usbInterface;
UsbDeviceConnection usbDeviceConnection;

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

textStatus = (TextView)findViewById(R.id.textstatus);

textDeviceName = (TextView)findViewById(R.id.textdevicename);
textInfo = (TextView) findViewById(R.id.info);
textSearchedEndpoint = (TextView)findViewById(R.id.searchedendpoint);

//register the broadcast receiver
mPermissionIntent = PendingIntent.getBroadcast(this, 0, new Intent(ACTION_USB_PERMISSION), 0);
IntentFilter filter = new IntentFilter(ACTION_USB_PERMISSION);
registerReceiver(mUsbReceiver, filter);

registerReceiver(mUsbDeviceReceiver, new IntentFilter(UsbManager.ACTION_USB_DEVICE_ATTACHED));
registerReceiver(mUsbDeviceReceiver, new IntentFilter(UsbManager.ACTION_USB_DEVICE_DETACHED));

connectUsb();
}

@Override
protected void onDestroy() {
releaseUsb();
unregisterReceiver(mUsbReceiver);
unregisterReceiver(mUsbDeviceReceiver);
super.onDestroy();
}

private void connectUsb(){

Toast.makeText(MainActivity.this,
"connectUsb()",
Toast.LENGTH_LONG).show();
textStatus.setText("connectUsb()");

searchEndPoint();
if(deviceFound != null){
doRawDescriptors();
}
}

private void releaseUsb(){

Toast.makeText(MainActivity.this,
"releaseUsb()",
Toast.LENGTH_LONG).show();
textStatus.setText("releaseUsb()");

if(usbDeviceConnection != null){
if(usbInterface != null){
usbDeviceConnection.releaseInterface(usbInterface);
usbInterface = null;
}
usbDeviceConnection.close();
usbDeviceConnection = null;
}

deviceFound = null;
usbInterfaceFound = null;
endpointIn = null;
endpointOut = null;
}

private void searchEndPoint(){

textInfo.setText("");
textSearchedEndpoint.setText("");

usbInterfaceFound = null;
endpointOut = null;
endpointIn = null;

//Search device for targetVendorID and targetProductID
if(deviceFound == null){
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();

if(device.getVendorId()==targetVendorID){
if(device.getProductId()==targetProductID){
deviceFound = device;
}
}
}
}

if(deviceFound==null){
Toast.makeText(MainActivity.this,
"device not found",
Toast.LENGTH_LONG).show();
textStatus.setText("device not found");
}else{
String s = deviceFound.toString() + "\n" +
"DeviceID: " + deviceFound.getDeviceId() + "\n" +
"DeviceName: " + deviceFound.getDeviceName() + "\n" +
"DeviceClass: " + deviceFound.getDeviceClass() + " - "
+ translateDeviceClass(deviceFound.getDeviceClass()) + "\n" +
"DeviceSubClass: " + deviceFound.getDeviceSubclass() + "\n" +
"VendorID: " + deviceFound.getVendorId() + "\n" +
"ProductID: " + deviceFound.getProductId() + "\n" +
"InterfaceCount: " + deviceFound.getInterfaceCount();
textInfo.setText(s);

//Search for UsbInterface with Endpoint of USB_ENDPOINT_XFER_BULK,
//and direction USB_DIR_OUT and USB_DIR_IN

for(int i=0; i<deviceFound.getInterfaceCount(); i++){
UsbInterface usbif = deviceFound.getInterface(i);

UsbEndpoint tOut = null;
UsbEndpoint tIn = null;

int tEndpointCnt = usbif.getEndpointCount();
if(tEndpointCnt>=2){
for(int j=0; j<tEndpointCnt; j++){
if(usbif.getEndpoint(j).getType() ==
UsbConstants.USB_ENDPOINT_XFER_BULK){
if(usbif.getEndpoint(j).getDirection() ==
UsbConstants.USB_DIR_OUT){
tOut = usbif.getEndpoint(j);
}else if(usbif.getEndpoint(j).getDirection() ==
UsbConstants.USB_DIR_IN){
tIn = usbif.getEndpoint(j);
}
}
}

if(tOut!=null && tIn!=null){
//This interface have both USB_DIR_OUT
//and USB_DIR_IN of USB_ENDPOINT_XFER_BULK
usbInterfaceFound = usbif;
endpointOut = tOut;
endpointIn = tIn;
}
}

}

if(usbInterfaceFound==null){
textSearchedEndpoint.setText("No suitable interface found!");
}else{
textSearchedEndpoint.setText(
"UsbInterface found: " + usbInterfaceFound.toString() + "\n\n" +
"Endpoint OUT: " + endpointOut.toString() + "\n\n" +
"Endpoint IN: " + endpointIn.toString());
}
}
}

private final BroadcastReceiver mUsbReceiver =
new BroadcastReceiver() {

@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (ACTION_USB_PERMISSION.equals(action)) {

Toast.makeText(MainActivity.this,
"ACTION_USB_PERMISSION",
Toast.LENGTH_LONG).show();
textStatus.setText("ACTION_USB_PERMISSION");

synchronized (this) {
UsbDevice device = (UsbDevice)intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);

if (intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
if(device != null){
doReadRawDescriptors(device);
}
}
else {
Toast.makeText(MainActivity.this,
"permission denied for device " + device,
Toast.LENGTH_LONG).show();
textStatus.setText("permission denied for device " + device);
}
}
}
}
};

private final BroadcastReceiver mUsbDeviceReceiver =
new BroadcastReceiver() {

@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (UsbManager.ACTION_USB_DEVICE_ATTACHED.equals(action)) {

deviceFound = (UsbDevice)intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
Toast.makeText(MainActivity.this,
"ACTION_USB_DEVICE_ATTACHED: \n" +
deviceFound.toString(),
Toast.LENGTH_LONG).show();
textStatus.setText("ACTION_USB_DEVICE_ATTACHED: \n" +
deviceFound.toString());

connectUsb();

}else if (UsbManager.ACTION_USB_DEVICE_DETACHED.equals(action)) {

UsbDevice device = (UsbDevice)intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);

Toast.makeText(MainActivity.this,
"ACTION_USB_DEVICE_DETACHED: \n" +
device.toString(),
Toast.LENGTH_LONG).show();
textStatus.setText("ACTION_USB_DEVICE_DETACHED: \n" +
device.toString());

if(device!=null){
if(device == deviceFound){
releaseUsb();
}
}

textInfo.setText("");
}
}

};

private void doRawDescriptors(){
UsbDevice deviceToRead = deviceFound;
UsbManager manager = (UsbManager) getSystemService(Context.USB_SERVICE);

Boolean permitToRead = manager.hasPermission(deviceToRead);

if(permitToRead){
doReadRawDescriptors(deviceToRead);
}else{
manager.requestPermission(deviceToRead, mPermissionIntent);
Toast.makeText(MainActivity.this,
"Permission: " + permitToRead,
Toast.LENGTH_LONG).show();
textStatus.setText("Permission: " + permitToRead);
}
}

private void doReadRawDescriptors(UsbDevice device){
final int STD_USB_REQUEST_GET_DESCRIPTOR = 0x06;
final int LIBUSB_DT_STRING = 0x03;

boolean forceClaim = true;

byte[] buffer = new byte[255];
int indexManufacturer = 14;
int indexProduct = 15;
String stringManufacturer = "";
String stringProduct = "";

UsbManager manager = (UsbManager) getSystemService(Context.USB_SERVICE);
usbDeviceConnection = manager.openDevice(device);
if(usbDeviceConnection != null){
usbInterface = device.getInterface(0);
usbDeviceConnection.claimInterface(usbInterface, forceClaim);

byte[] rawDescriptors = usbDeviceConnection.getRawDescriptors();

int lengthManufacturer = usbDeviceConnection.controlTransfer(
UsbConstants.USB_DIR_IN|UsbConstants.USB_TYPE_STANDARD,
STD_USB_REQUEST_GET_DESCRIPTOR,
(LIBUSB_DT_STRING << 8) | rawDescriptors[indexManufacturer],
0,
buffer,
0xFF,
0);
try {
stringManufacturer = new String(buffer, 2, lengthManufacturer-2, "UTF-16LE");
} catch (UnsupportedEncodingException e) {
Toast.makeText(MainActivity.this, e.toString(), Toast.LENGTH_LONG).show();
textStatus.setText(e.toString());
}

int lengthProduct = usbDeviceConnection.controlTransfer(
UsbConstants.USB_DIR_IN|UsbConstants.USB_TYPE_STANDARD,
STD_USB_REQUEST_GET_DESCRIPTOR,
(LIBUSB_DT_STRING << 8) | rawDescriptors[indexProduct],
0,
buffer,
0xFF,
0);
try {
stringProduct = new String(buffer, 2, lengthProduct-2, "UTF-16LE");
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

Toast.makeText(MainActivity.this,
"Manufacturer: " + stringManufacturer + "\n" +
"Product: " + stringProduct,
Toast.LENGTH_LONG).show();
textStatus.setText("Manufacturer: " + stringManufacturer + "\n" +
"Product: " + stringProduct);
}else{
Toast.makeText(MainActivity.this,
"open failed",
Toast.LENGTH_LONG).show();
textStatus.setText("open failed");
}
}

private String translateDeviceClass(int deviceClass){
switch(deviceClass){
case UsbConstants.USB_CLASS_APP_SPEC:
return "Application specific USB class";
case UsbConstants.USB_CLASS_AUDIO:
return "USB class for audio devices";
case UsbConstants.USB_CLASS_CDC_DATA:
return "USB class for CDC devices (communications device class)";
case UsbConstants.USB_CLASS_COMM:
return "USB class for communication devices";
case UsbConstants.USB_CLASS_CONTENT_SEC:
return "USB class for content security devices";
case UsbConstants.USB_CLASS_CSCID:
return "USB class for content smart card devices";
case UsbConstants.USB_CLASS_HID:
return "USB class for human interface devices (for example, mice and keyboards)";
case UsbConstants.USB_CLASS_HUB:
return "USB class for USB hubs";
case UsbConstants.USB_CLASS_MASS_STORAGE:
return "USB class for mass storage devices";
case UsbConstants.USB_CLASS_MISC:
return "USB class for wireless miscellaneous devices";
case UsbConstants.USB_CLASS_PER_INTERFACE:
return "USB class indicating that the class is determined on a per-interface basis";
case UsbConstants.USB_CLASS_PHYSICA:
return "USB class for physical devices";
case UsbConstants.USB_CLASS_PRINTER:
return "USB class for printers";
case UsbConstants.USB_CLASS_STILL_IMAGE:
return "USB class for still image devices (digital cameras)";
case UsbConstants.USB_CLASS_VENDOR_SPEC:
return "Vendor specific USB class";
case UsbConstants.USB_CLASS_VIDEO:
return "USB class for video devices";
case UsbConstants.USB_CLASS_WIRELESS_CONTROLLER:
return "USB class for wireless controller devices";
default: return "Unknown USB class!";

}
}

}

activity_main.xml
<LinearLayout 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"
android:orientation="vertical"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:autoLink="web"
android:text="http://arteluzevida.blogspot.com/"
android:textStyle="bold" />

<TextView
android:id="@+id/textstatus"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textStyle="bold" />

<TextView
android:id="@+id/textdevicename"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textStyle="bold|italic" />

<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent" >

<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >

<TextView
android:id="@+id/info"
android:layout_width="match_parent"
android:layout_height="wrap_content" />

<TextView
android:id="@+id/searchedendpoint"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textStyle="bold" />

</LinearLayout>
</ScrollView>

</LinearLayout>




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Step-by-step: Android USB Host Mode programming