Communicating with custom made USB device on android

StackOverflow https://stackoverflow.com//questions/23042753

  •  21-12-2019
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Question

I am building an application to communicate with a custom made board (PIC16F1454) through USB. I tested the board communication using terminal applications on the phone and the laptop and it works perfectly.

I built an application to send and receive data from the board but nothing seems to work. Below is my class responsible for the communication:

package com.fyp.eece502androidusb;

import java.util.HashMap;
import java.util.Iterator;

import android.app.Activity;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
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.util.Log;

public class UsbController {

    private final Context mApplicationContext;
    private final UsbManager mUsbManager;
    private final IUsbConnectionHandler mConnectionHandler;
    private final int VID;
    private final int PID;
    protected static final String ACTION_USB_PERMISSION = "com.fyp.eece502androidusb.USB";

    /**
     * Activity is needed for onResult
     * 
     * @param parentActivity
     */
    public UsbController(Activity parentActivity,
            IUsbConnectionHandler connectionHandler, int vid, int pid) {
        mApplicationContext = parentActivity.getApplicationContext();
        mConnectionHandler = connectionHandler;
        mUsbManager = (UsbManager) mApplicationContext
                .getSystemService(Context.USB_SERVICE);
        VID = vid;
        PID = pid;
        init();
    }

    private void init() {
        enumerate(new IPermissionListener() {
            @Override
            public void onPermissionDenied(UsbDevice d) {
                UsbManager usbman = (UsbManager) mApplicationContext
                        .getSystemService(Context.USB_SERVICE);
                PendingIntent pi = PendingIntent.getBroadcast(
                        mApplicationContext, 0, new Intent(
                                ACTION_USB_PERMISSION), 0);
                mApplicationContext.registerReceiver(mPermissionReceiver,
                        new IntentFilter(ACTION_USB_PERMISSION));
                usbman.requestPermission(d, pi);
            }
        });
    }

    public void stop() {
        mStop = true;
        synchronized (sSendLock) {
            sSendLock.notify();
        }
        try {
            if (mUsbThread != null)
                mUsbThread.join();
        } catch (InterruptedException e) {
            e(e);
        }
        mStop = false;
        mLoop = null;
        mUsbThread = null;

        try {
            mApplicationContext.unregisterReceiver(mPermissionReceiver);
        } catch (IllegalArgumentException e) {
        }
        ;// bravo
    }

    private UsbRunnable mLoop;
    private Thread mUsbThread;

    private void startHandler(UsbDevice d) {
        if (mLoop != null) {
            mConnectionHandler.onErrorLooperRunningAlready();
            return;
        }
        mLoop = new UsbRunnable(d);
        mUsbThread = new Thread(mLoop);
        mUsbThread.start();
    }

    public void send(byte data) {
        mData = data;
        synchronized (sSendLock) {
            sSendLock.notify();
        }
    }

    private void enumerate(IPermissionListener listener) {
        l("enumerating");
        HashMap<String, UsbDevice> devlist = mUsbManager.getDeviceList();
        Iterator<UsbDevice> deviter = devlist.values().iterator();
        while (deviter.hasNext()) {
            UsbDevice d = deviter.next();
            l("Found device: "
                    + String.format("%04X:%04X", d.getVendorId(),
                            d.getProductId()));
            if (d.getVendorId() == VID && d.getProductId() == PID) {
                l("Device under: " + d.getDeviceName());
                if (!mUsbManager.hasPermission(d))
                    listener.onPermissionDenied(d);
                else {
                    startHandler(d);
                    return;
                }
                break;
            }
        }
        l("no more devices found");
        mConnectionHandler.onDeviceNotFound();
    }

    private class PermissionReceiver extends BroadcastReceiver {
        private final IPermissionListener mPermissionListener;

        public PermissionReceiver(IPermissionListener permissionListener) {
            mPermissionListener = permissionListener;
        }

        @Override
        public void onReceive(Context context, Intent intent) {
            mApplicationContext.unregisterReceiver(this);
            if (intent.getAction().equals(ACTION_USB_PERMISSION)) {
                if (!intent.getBooleanExtra(
                        UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
                    mPermissionListener.onPermissionDenied((UsbDevice) intent
                            .getParcelableExtra(UsbManager.EXTRA_DEVICE));
                } else {
                    l("Permission granted");
                    UsbDevice dev = (UsbDevice) intent
                            .getParcelableExtra(UsbManager.EXTRA_DEVICE);
                    if (dev != null) {
                        if (dev.getVendorId() == VID
                                && dev.getProductId() == PID) {
                            startHandler(dev);// has new thread
                        }
                    } else {
                        e("device not present!");
                    }
                }
            }
        }

    }

    // MAIN LOOP
    private static final Object[] sSendLock = new Object[] {};
    private boolean mStop = false;
    private byte mData = 0x00;

    private class UsbRunnable implements Runnable {
        private final UsbDevice mDevice;

        UsbRunnable(UsbDevice dev) {
            mDevice = dev;
        }

        @Override
        public void run() {// here the main USB functionality is implemented
            UsbDeviceConnection conn = mUsbManager.openDevice(mDevice);
            if (!conn.claimInterface(mDevice.getInterface(1), true)) {
                return;
            }

            // controlTransfer
            int baudRate = 115200;
            int stopBits = 1;
            int parity = 0;
            int dataBits = 8;
            byte[] msg = { (byte) (baudRate & 0xff),
                    (byte) ((baudRate >> 8) & 0xff),
                    (byte) ((baudRate >> 16) & 0xff),
                    (byte) ((baudRate >> 24) & 0xff),

                    (byte) stopBits, (byte) parity, (byte) dataBits };
            int USB_RT_ACM = UsbConstants.USB_TYPE_CLASS | 1;

            UsbControllerActivity.conn1Reply = conn.controlTransfer(USB_RT_ACM,
                    34, 0x03, 0, null, 0, 0);
            UsbControllerActivity.conn2Reply = conn.controlTransfer(USB_RT_ACM,
                    32, 0, 0, msg, msg != null ? msg.length : 0, 0);
            //

            UsbEndpoint epIN = null;
            UsbEndpoint epOUT = null;

            UsbInterface usbIf = mDevice.getInterface(1);
            for (int i = 0; i < usbIf.getEndpointCount(); i++) {
                if (usbIf.getEndpoint(i).getType() == UsbConstants.USB_ENDPOINT_XFER_BULK) {
                    if (usbIf.getEndpoint(i).getDirection() == UsbConstants.USB_DIR_IN) {
                        epIN = usbIf.getEndpoint(i);
                        UsbControllerActivity.epINExists = true;
                    } else {
                        epOUT = usbIf.getEndpoint(i);
                        UsbControllerActivity.epOUTExists = true;
                    }
                }
            }

            for (;;) {// this is the main loop for transferring
                synchronized (sSendLock) {
                    try {
                        sSendLock.wait();
                    } catch (InterruptedException e) {
                        if (mStop) {
                            mConnectionHandler.onUSBStopped();
                            return;
                        }
                        e.printStackTrace();
                    }
                }
                UsbControllerActivity.mDataSent = new byte[] { (byte) (0x04) };
                UsbControllerActivity.bulkXFEROutReply = conn.bulkTransfer(
                        epOUT, UsbControllerActivity.mDataSent, 1, 0);
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                UsbControllerActivity.bulkXFERInReply = conn.bulkTransfer(epIN,
                        UsbControllerActivity.mDataReceived, 10, 0);

                if (mStop) {
                    mConnectionHandler.onUSBStopped();
                    return;
                }
            }
        }
    }

    // END MAIN LOOP
    private BroadcastReceiver mPermissionReceiver = new PermissionReceiver(
            new IPermissionListener() {
                @Override
                public void onPermissionDenied(UsbDevice d) {
                    l("Permission denied on " + d.getDeviceId());
                }
            });

    private static interface IPermissionListener {
        void onPermissionDenied(UsbDevice d);
    }

    public final static String TAG = "USBController";

    private void l(Object msg) {
        Log.d(TAG, ">==< " + msg.toString() + " >==<");
    }

    private void e(Object msg) {
        Log.e(TAG, ">==< " + msg.toString() + " >==<");
    }
}

I'm getting returned values of 0 and 7 for the control transfers, and 1 for the bulk transfer when sending and nothing is received.

Although the bulk transfer indicates that the value is sent, nothing changes on the receiving side (a blinking LED on the board).

My speculation is that there must be something wrong with the control transfer:

int baudRate = 115200;
int stopBits = 1;
int parity = 0;
int dataBits = 8;
byte[] msg = { (byte) (baudRate & 0xff),
        (byte) ((baudRate >> 8) & 0xff),
        (byte) ((baudRate >> 16) & 0xff),
        (byte) ((baudRate >> 24) & 0xff),

        (byte) stopBits, (byte) parity, (byte) dataBits };
int USB_RT_ACM = UsbConstants.USB_TYPE_CLASS | 1;

UsbControllerActivity.conn1Reply = conn.controlTransfer(USB_RT_ACM,
        34, 0x03, 0, null, 0, 0);
UsbControllerActivity.conn2Reply = conn.controlTransfer(USB_RT_ACM,
        32, 0, 0, msg, msg != null ? msg.length : 0, 0);

The USB device is configured as a CDC device.

Any help?

Was it helpful?

Solution

Thanks to the comment from Chris Stratton, I was able to find the problem in my code.

  1. I was sending 0x04 (Ctrl-D) instead of 0x34 (4)
  2. The controlTransfer seems to be unnecessary, I'm using PIC16F1454 with built in USB functionality
  3. The receiving buffer was smaller than the reply of the PIC which also caused problems

The modified code is below:

package com.fyp.eece502androidusb;

import java.util.HashMap;
import java.util.Iterator;

import android.app.Activity;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
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.util.Log;

public class UsbController {

    private final Context mApplicationContext;
    private final UsbManager mUsbManager;
    private final IUsbConnectionHandler mConnectionHandler;
    private final int VID;
    private final int PID;
    protected static final String ACTION_USB_PERMISSION = "com.fyp.eece502androidusb.USB";

    /**
     * Activity is needed for onResult
     * 
     * @param parentActivity
     */
    public UsbController(Activity parentActivity,
            IUsbConnectionHandler connectionHandler, int vid, int pid) {
        mApplicationContext = parentActivity.getApplicationContext();
        mConnectionHandler = connectionHandler;
        mUsbManager = (UsbManager) mApplicationContext
                .getSystemService(Context.USB_SERVICE);
        VID = vid;
        PID = pid;
        init();
    }

    private void init() {
        enumerate(new IPermissionListener() {
            @Override
            public void onPermissionDenied(UsbDevice d) {
                UsbManager usbman = (UsbManager) mApplicationContext
                        .getSystemService(Context.USB_SERVICE);
                PendingIntent pi = PendingIntent.getBroadcast(
                        mApplicationContext, 0, new Intent(
                                ACTION_USB_PERMISSION), 0);
                mApplicationContext.registerReceiver(mPermissionReceiver,
                        new IntentFilter(ACTION_USB_PERMISSION));
                usbman.requestPermission(d, pi);
            }
        });
    }

    public void stop() {
        mStop = true;
        synchronized (sSendLock) {
            sSendLock.notify();
        }
        try {
            if (mUsbThread != null)
                mUsbThread.join();
        } catch (InterruptedException e) {
            e(e);
        }
        mStop = false;
        mLoop = null;
        mUsbThread = null;

        try {
            mApplicationContext.unregisterReceiver(mPermissionReceiver);
        } catch (IllegalArgumentException e) {
        }
    }

    private UsbRunnable mLoop;
    private Thread mUsbThread;

    private void startHandler(UsbDevice d) {
        if (mLoop != null) {
            mConnectionHandler.onErrorLooperRunningAlready();
            return;
        }
        mLoop = new UsbRunnable(d);
        mUsbThread = new Thread(mLoop);
        mUsbThread.start();
    }

    public void send(byte data) {
        mData = data;
        synchronized (sSendLock) {
            sSendLock.notify();
        }
    }

    private void enumerate(IPermissionListener listener) {
        l("enumerating");
        HashMap<String, UsbDevice> devlist = mUsbManager.getDeviceList();
        Iterator<UsbDevice> deviter = devlist.values().iterator();
        while (deviter.hasNext()) {
            UsbDevice d = deviter.next();
            l("Found device: "
                    + String.format("%04X:%04X", d.getVendorId(),
                            d.getProductId()));
            if (d.getVendorId() == VID && d.getProductId() == PID) {
                l("Device under: " + d.getDeviceName());
                if (!mUsbManager.hasPermission(d))
                    listener.onPermissionDenied(d);
                else {
                    startHandler(d);
                    return;
                }
                break;
            }
        }
        l("no more devices found");
        mConnectionHandler.onDeviceNotFound();
    }

    private class PermissionReceiver extends BroadcastReceiver {
        private final IPermissionListener mPermissionListener;

        public PermissionReceiver(IPermissionListener permissionListener) {
            mPermissionListener = permissionListener;
        }

        @Override
        public void onReceive(Context context, Intent intent) {
            mApplicationContext.unregisterReceiver(this);
            if (intent.getAction().equals(ACTION_USB_PERMISSION)) {
                if (!intent.getBooleanExtra(
                        UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
                    mPermissionListener.onPermissionDenied((UsbDevice) intent
                            .getParcelableExtra(UsbManager.EXTRA_DEVICE));
                } else {
                    l("Permission granted");
                    UsbDevice dev = (UsbDevice) intent
                            .getParcelableExtra(UsbManager.EXTRA_DEVICE);
                    if (dev != null) {
                        if (dev.getVendorId() == VID
                                && dev.getProductId() == PID) {
                            startHandler(dev);// has new thread
                        }
                    } else {
                        e("device not present!");
                    }
                }
            }
        }

    }

    // MAIN LOOP
    private static final Object[] sSendLock = new Object[] {};
    private boolean mStop = false;
    private byte mData = 0x00;

    private class UsbRunnable implements Runnable {
        private final UsbDevice mDevice;

        UsbRunnable(UsbDevice dev) {
            mDevice = dev;
        }

        @Override
        public void run() {// here the main USB functionality is implemented
            UsbDeviceConnection conn = mUsbManager.openDevice(mDevice);
            if (!conn.claimInterface(mDevice.getInterface(1), true)) {
                return;
            }

            UsbEndpoint epIN = null;
            UsbEndpoint epOUT = null;

            UsbInterface usbIf = mDevice.getInterface(1);
            for (int i = 0; i < usbIf.getEndpointCount(); i++) {
                if (usbIf.getEndpoint(i).getType() == UsbConstants.USB_ENDPOINT_XFER_BULK) {
                    if (usbIf.getEndpoint(i).getDirection() == UsbConstants.USB_DIR_IN) {
                        epIN = usbIf.getEndpoint(i);
                        UsbControllerActivity.epINExists = true;
                    } else {
                        epOUT = usbIf.getEndpoint(i);
                        UsbControllerActivity.epOUTExists = true;
                    }
                }
            }

            for (;;) {// this is the main loop for transferring
                synchronized (sSendLock) {
                    try {
                        sSendLock.wait();
                    } catch (InterruptedException e) {
                        if (mStop) {
                            mConnectionHandler.onUSBStopped();
                            return;
                        }
                        e.printStackTrace();
                    }
                }
                UsbControllerActivity.mDataSent = new byte[] { (byte) (0x34) };
                UsbControllerActivity.bulkXFEROutReply = conn.bulkTransfer(
                        epOUT, UsbControllerActivity.mDataSent, 1, 0);
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                UsbControllerActivity.bulkXFERInReply = conn.bulkTransfer(epIN,
                        UsbControllerActivity.mDataReceived, 20, 0);

                if (mStop) {
                    mConnectionHandler.onUSBStopped();
                    return;
                }
            }
        }
    }

    // END MAIN LOOP
    private BroadcastReceiver mPermissionReceiver = new PermissionReceiver(
            new IPermissionListener() {
                @Override
                public void onPermissionDenied(UsbDevice d) {
                    l("Permission denied on " + d.getDeviceId());
                }
            });

    private static interface IPermissionListener {
        void onPermissionDenied(UsbDevice d);
    }

    public final static String TAG = "USBController";

    private void l(Object msg) {
        Log.d(TAG, ">==< " + msg.toString() + " >==<");
    }

    private void e(Object msg) {
        Log.e(TAG, ">==< " + msg.toString() + " >==<");
    }
}
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