Using the Android Host Host API to read my USB game controller or other data from a USB device

Question

I'm trying to use the Android Host Host API to read the data from a USB stick controller, as soon as I get this to work, I will connect another device for testing. My game controller is connected to my Android phone using an OTG cable. Now I can get information about devices, endpoints, but I do not know how to read the raw data and display it.

Can someone help me? Some code examples will be appreciated.

TextView countDisplay; ArrayList<String> listItems = new ArrayList<String>(); ArrayAdapter<String> adapter; String values = ""; UsbManager mManager; UsbDevice device = null; private byte[] bytes; private static int TIMEOUT = 0; private boolean forceClaim = true; static PendingIntent mPermissionIntent; UsbDeviceConnection connection = null; UsbEndpoint InputEndpoint = null; UsbEndpoint OutputEndpoint = null; private Handler mHandler = new Handler(); @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); mManager = (UsbManager) getSystemService(Context.USB_SERVICE); mPermissionIntent = PendingIntent.getBroadcast(this, 0, new Intent( "com.android.example.USB_PERMISSION"), 0); IntentFilter filter = new IntentFilter(); filter.addAction(UsbManager.ACTION_USB_DEVICE_ATTACHED); filter.addAction(UsbManager.ACTION_USB_DEVICE_DETACHED); registerReceiver(mUsbReceiver, filter); HashMap<String, UsbDevice> deviceList = mManager.getDeviceList(); values = values + "deviceListSize:" + deviceList.size() + ",tostring:" + deviceList.toString(); Iterator<UsbDevice> deviceIterator = deviceList.values().iterator(); while (deviceIterator.hasNext()) { device = deviceIterator.next(); values = values + ",device id:" + device.getDeviceId() + ",device name:" + device.getDeviceName(); values = values + ",Protocol:" + device.getDeviceProtocol() + ",ProductId:" + device.getProductId(); values = values + ",DeviceClass:" + device.getDeviceClass() + ",VendorId:" + device.getVendorId(); } if (device != null) { values = values + ",getInterfaceCount:" + device.getInterfaceCount(); UsbInterface intf = device.getInterface(0); values = values + ",intf.getEndpointCount():" + intf.getEndpointCount(); UsbEndpoint endpoint1 = intf.getEndpoint(0); UsbEndpoint endpoint2 = intf.getEndpoint(1); mManager.requestPermission(device, mPermissionIntent); if (mManager.hasPermission(device)) { values = values + ",has permission over device!"; connection = mManager.openDevice(device); if (connection == null) { values = values + ",connection null"; } else { values = values + ",getFileDescriptor:" + connection.getFileDescriptor(); if (endpoint1.getDirection() == UsbConstants.USB_DIR_IN) { InputEndpoint = endpoint1; } else { OutputEndpoint = endpoint1; } if (endpoint2.getDirection() == UsbConstants.USB_DIR_IN) { InputEndpoint = endpoint2; } else { OutputEndpoint = endpoint2; } } if (InputEndpoint == null) { countDisplay.setText(values + ",InputEndpoint is null"); } if (OutputEndpoint == null) { countDisplay.setText(values + ",OutputEndPoint is null"); } connection.claimInterface(intf, forceClaim); mHandler.postDelayed(runnable, 1); } else { values = values + ",Do not have permission over device!"; } } setContentView(R.layout.activity_main); LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE); View v = inflater.inflate(R.layout.activity_main, null); LinearLayout ll = new LinearLayout(this); ll.setOrientation(LinearLayout.VERTICAL); int counter = 1; countDisplay = new TextView(this); ll.addView(countDisplay); countDisplay.setText(values + ",counter here"); final Button button = new Button(this); button.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub if (device != null && mManager.hasPermission(device)) { values = values + ",device id:" + device.getDeviceId() + ",device name:" + device.getDeviceName(); values = values + ",Protocol:" + device.getDeviceProtocol() + ",ProductId:" + device.getProductId(); values = values + ",DeviceClass:" + device.getDeviceClass() + ",VendorId:" + device.getVendorId(); countDisplay.setText(values + ",okok"); } else { if (device != null) mManager.requestPermission(device, mPermissionIntent); } } }); ll.addView(button); setContentView(ll); } 

And Runnable:

 private Runnable runnable = new Runnable() { public void run() { if (connection != null) { int count = connection.bulkTransfer(InputEndpoint, bytes, bytes.length, TIMEOUT); countDisplay.setText(values + ",bultTransferNo:" + count); countDisplay.setText(values + "bulkValue:" + bytes); } else { countDisplay.setText(values + ",connection is null"); } } }; 

Answer 1

This program serves as an example of the following USB host functions:

• Appropriate devices based on interface class, subclass, and protocol (see device_filter.xml)

• Volume Asynchronous I / O

All code Copyright:

  /* * Copyright (C) 2011 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ 

Adbdevice

  package com.android.adb; import android.hardware.usb.UsbConstants; import android.hardware.usb.UsbDeviceConnection; import android.hardware.usb.UsbEndpoint; import android.hardware.usb.UsbInterface; import android.hardware.usb.UsbRequest; import android.util.SparseArray; import java.util.LinkedList; /* This class represents a USB device that supports the adb protocol. */ public class AdbDevice { private final AdbTestActivity mActivity; private final UsbDeviceConnection mDeviceConnection; private final UsbEndpoint mEndpointOut; private final UsbEndpoint mEndpointIn; private String mSerial; // pool of requests for the OUT endpoint private final LinkedList<UsbRequest> mOutRequestPool = new LinkedList<UsbRequest>(); // pool of requests for the IN endpoint private final LinkedList<UsbRequest> mInRequestPool = new LinkedList<UsbRequest>(); // list of currently opened sockets private final SparseArray<AdbSocket> mSockets = new SparseArray<AdbSocket>(); private int mNextSocketId = 1; private final WaiterThread mWaiterThread = new WaiterThread(); public AdbDevice(AdbTestActivity activity, UsbDeviceConnection connection, UsbInterface intf) { mActivity = activity; mDeviceConnection = connection; mSerial = connection.getSerial(); UsbEndpoint epOut = null; UsbEndpoint epIn = null; // look for our bulk endpoints for (int i = 0; i < intf.getEndpointCount(); i++) { UsbEndpoint ep = intf.getEndpoint(i); if (ep.getType() == UsbConstants.USB_ENDPOINT_XFER_BULK) { if (ep.getDirection() == UsbConstants.USB_DIR_OUT) { epOut = ep; } else { epIn = ep; } } } if (epOut == null || epIn == null) { throw new IllegalArgumentException("not all endpoints found"); } mEndpointOut = epOut; mEndpointIn = epIn; } // return device serial number public String getSerial() { return mSerial; } // get an OUT request from our pool public UsbRequest getOutRequest() { synchronized(mOutRequestPool) { if (mOutRequestPool.isEmpty()) { UsbRequest request = new UsbRequest(); request.initialize(mDeviceConnection, mEndpointOut); return request; } else { return mOutRequestPool.removeFirst(); } } } // return an OUT request to the pool public void releaseOutRequest(UsbRequest request) { synchronized (mOutRequestPool) { mOutRequestPool.add(request); } } // get an IN request from the pool public UsbRequest getInRequest() { synchronized(mInRequestPool) { if (mInRequestPool.isEmpty()) { UsbRequest request = new UsbRequest(); request.initialize(mDeviceConnection, mEndpointIn); return request; } else { return mInRequestPool.removeFirst(); } } } public void start() { mWaiterThread.start(); connect(); } public AdbSocket openSocket(String destination) { AdbSocket socket; synchronized (mSockets) { int id = mNextSocketId++; socket = new AdbSocket(this, id); mSockets.put(id, socket); } if (socket.open(destination)) { return socket; } else { return null; } } private AdbSocket getSocket(int id) { synchronized (mSockets) { return mSockets.get(id); } } public void socketClosed(AdbSocket socket) { synchronized (mSockets) { mSockets.remove(socket.getId()); } } // send a connect command private void connect() { AdbMessage message = new AdbMessage(); message.set(AdbMessage.A_CNXN, AdbMessage.A_VERSION, AdbMessage.MAX_PAYLOAD, "host::\0"); message.write(this); } // handle connect response private void handleConnect(AdbMessage message) { if (message.getDataString().startsWith("device:")) { log("connected"); mActivity.deviceOnline(this); } } public void stop() { synchronized (mWaiterThread) { mWaiterThread.mStop = true; } } // dispatch a message from the device void dispatchMessage(AdbMessage message) { int command = message.getCommand(); switch (command) { case AdbMessage.A_SYNC: log("got A_SYNC"); break; case AdbMessage.A_CNXN: handleConnect(message); break; case AdbMessage.A_OPEN: case AdbMessage.A_OKAY: case AdbMessage.A_CLSE: case AdbMessage.A_WRTE: AdbSocket socket = getSocket(message.getArg1()); if (socket == null) { log("ERROR socket not found"); } else { socket.handleMessage(message); } break; } } void log(String s) { mActivity.log(s); } private class WaiterThread extends Thread { public boolean mStop; public void run() { // start out with a command read AdbMessage currentCommand = new AdbMessage(); AdbMessage currentData = null; // FIXME error checking currentCommand.readCommand(getInRequest()); while (true) { synchronized (this) { if (mStop) { return; } } UsbRequest request = mDeviceConnection.requestWait(); if (request == null) { break; } AdbMessage message = (AdbMessage)request.getClientData(); request.setClientData(null); AdbMessage messageToDispatch = null; if (message == currentCommand) { int dataLength = message.getDataLength(); // read data if length > 0 if (dataLength > 0) { message.readData(getInRequest(), dataLength); currentData = message; } else { messageToDispatch = message; } currentCommand = null; } else if (message == currentData) { messageToDispatch = message; currentData = null; } if (messageToDispatch != null) { // queue another read first currentCommand = new AdbMessage(); currentCommand.readCommand(getInRequest()); // then dispatch the current message dispatchMessage(messageToDispatch); } // put request back into the appropriate pool if (request.getEndpoint() == mEndpointOut) { releaseOutRequest(request); } else { synchronized (mInRequestPool) { mInRequestPool.add(request); } } } } } } 

Adbmessage

  package com.android.adb; import android.hardware.usb.UsbRequest; import java.nio.ByteBuffer; import java.nio.ByteOrder; /* This class encapsulates and adb command packet */ public class AdbMessage { // command names public static final int A_SYNC = 0x434e5953; public static final int A_CNXN = 0x4e584e43; public static final int A_OPEN = 0x4e45504f; public static final int A_OKAY = 0x59414b4f; public static final int A_CLSE = 0x45534c43; public static final int A_WRTE = 0x45545257; // ADB protocol version public static final int A_VERSION = 0x01000000; public static final int MAX_PAYLOAD = 4096; private final ByteBuffer mMessageBuffer; private final ByteBuffer mDataBuffer; public AdbMessage() { mMessageBuffer = ByteBuffer.allocate(24); mDataBuffer = ByteBuffer.allocate(MAX_PAYLOAD); mMessageBuffer.order(ByteOrder.LITTLE_ENDIAN); mDataBuffer.order(ByteOrder.LITTLE_ENDIAN); } // sets the fields in the command header public void set(int command, int arg0, int arg1, byte[] data) { mMessageBuffer.putInt(0, command); mMessageBuffer.putInt(4, arg0); mMessageBuffer.putInt(8, arg1); mMessageBuffer.putInt(12, (data == null ? 0 : data.length)); mMessageBuffer.putInt(16, (data == null ? 0 : checksum(data))); mMessageBuffer.putInt(20, command ^ 0xFFFFFFFF); if (data != null) { mDataBuffer.put(data, 0, data.length); } } public void set(int command, int arg0, int arg1) { set(command, arg0, arg1, (byte[])null); } public void set(int command, int arg0, int arg1, String data) { // add trailing zero data += "\0"; set(command, arg0, arg1, data.getBytes()); } // returns the command message ID public int getCommand() { return mMessageBuffer.getInt(0); } // returns command first argument public int getArg0() { return mMessageBuffer.getInt(4); } // returns command second argument public int getArg1() { return mMessageBuffer.getInt(8); } // returns command data buffer public ByteBuffer getData() { return mDataBuffer; } // returns command data length public int getDataLength() { return mMessageBuffer.getInt(12); } // returns command data as a string public String getDataString() { int length = getDataLength(); if (length == 0) return null; // trim trailing zero return new String(mDataBuffer.array(), 0, length - 1); } public boolean write(AdbDevice device) { synchronized (device) { UsbRequest request = device.getOutRequest(); request.setClientData(this); if (request.queue(mMessageBuffer, 24)) { int length = getDataLength(); if (length > 0) { request = device.getOutRequest(); request.setClientData(this); if (request.queue(mDataBuffer, length)) { return true; } else { device.releaseOutRequest(request); return false; } } return true; } else { device.releaseOutRequest(request); return false; } } } public boolean readCommand(UsbRequest request) { request.setClientData(this); return request.queue(mMessageBuffer, 24); } public boolean readData(UsbRequest request, int length) { request.setClientData(this); return request.queue(mDataBuffer, length); } private static String extractString(ByteBuffer buffer, int offset, int length) { byte[] bytes = new byte[length]; for (int i = 0; i < length; i++) { bytes[i] = buffer.get(offset++); } return new String(bytes); } @Override public String toString() { String commandName = extractString(mMessageBuffer, 0, 4); int dataLength = getDataLength(); String result = "Adb Message: " + commandName + " arg0: " + getArg0() + " arg1: " + getArg1() + " dataLength: " + dataLength; if (dataLength > 0) { result += (" data: \"" + getDataString() + "\""); } return result; } private static int checksum(byte[] data) { int result = 0; for (int i = 0; i < data.length; i++) { int x = data[i]; // dang, no unsigned ints in java if (x < 0) x += 256; result += x; } return result; } } 

Adb socket

  package com.android.adb; /* This class represents an adb socket. adb supports multiple independent * socket connections to a single device. Typically a socket is created * for each adb command that is executed. */ public class AdbSocket { private final AdbDevice mDevice; private final int mId; private int mPeerId; public AdbSocket(AdbDevice device, int id) { mDevice = device; mId = id; } public int getId() { return mId; } public boolean open(String destination) { AdbMessage message = new AdbMessage(); message.set(AdbMessage.A_OPEN, mId, 0, destination); if (! message.write(mDevice)) { return false; } synchronized (this) { try { wait(); } catch (InterruptedException e) { return false; } } return true; } public void handleMessage(AdbMessage message) { switch (message.getCommand()) { case AdbMessage.A_OKAY: mPeerId = message.getArg0(); synchronized (this) { notify(); } break; case AdbMessage.A_WRTE: mDevice.log(message.getDataString()); sendReady(); break; } } private void sendReady() { AdbMessage message = new AdbMessage(); message.set(AdbMessage.A_OKAY, mId, mPeerId); message.write(mDevice); } } 

Answer 2

You can find more information about USB and connection in the next article.

http://android.serverbox.ch/?p=549

The last paragraph explains some problem that you may encounter. The example they provide can also show you how to read the data and how you will have to format the messages.

It looks like you are facing two problems. One setting of your code to read the message that Puspendu answers, and the second problem is how it communicates what messages you need to send to establish a connection, shake hands and determine good material, that is, the data you want.

Puspendu showed one example of reading and writing to a device. However, I would suggest that depending on the connected device, the structure of the handshake and messages will change, so you will have to look for these parts (I'm afraid I do not know other examples).