Question

我发现了一个用于读取FTDI设备USB数据的问题。 Transferring data USB 我将此代码用于多产设备，除了conn.bulkTransfer（）给出-1之外，还可以检测usb等。

    private class UsbRunnable implements Runnable {
    private final UsbDevice mDevice;

    UsbRunnable(UsbDevice dev) {
        mDevice = dev;
    }


    public void run() {//here the main USB functionality is implemented
        UsbDeviceConnection conn = mUsbManager.openDevice(mDevice);
        if (!conn.claimInterface(mDevice.getInterface(1), true)) {
            l("in run(), no connection");
            return;
        }
        l("in run(), connection");



         conn.controlTransfer(0x40, 0, 0, 0, null, 0, 0);// reset
         // mConnection.controlTransfer(0×40,
         // 0, 1, 0, null, 0,
         // 0);//clear Rx
         conn.controlTransfer(0x40, 0, 2, 0, null, 0, 0);// clear Tx
         conn.controlTransfer(0x40, 0x02, 0x0000, 0, null, 0, 0);// flow
                 // control
                 // none
         conn.controlTransfer(0x40, 0x03,  0xC04E, 0, null, 0, 0);// baudrate
                 // 38400
         conn.controlTransfer(0x40, 0x04, 0x0008, 0, null, 0, 0);// data bit
                 // 8, parity
                 // none,
                 // stop bit
                 // 1, tx off   




        UsbEndpoint epIN = null;
        UsbEndpoint epOUT = null;

        byte counter=0;
    //conn.bulkTransfer(epOUT, new byte[]{msData}, 1, 0);

        UsbInterface usbIf = mDevice.getInterface(0);
        for (int i = 0; i < usbIf.getEndpointCount(); i++) {
            l("EP: "
                    + String.format("0x%02X", usbIf.getEndpoint(i)
                            .getAddress()));
            l("Type:"+usbIf.getEndpoint(i).getType());
            if (usbIf.getEndpoint(i).getType() == UsbConstants.USB_ENDPOINT_XFER_INT) {
                l("Bulk Endpoint");
                l("direction: "+usbIf.getEndpoint(i).getDirection());
                if (usbIf.getEndpoint(i).getDirection() == UsbConstants.USB_DIR_IN)
                    epIN = usbIf.getEndpoint(i);

            }
            else l("no bulk");
            l("epIN: "+epIN.toString());
        }

        for (;;) {// this is the main loop for transferring
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

            // This is where it is meant to receive
            byte[] buffer = new byte[38400];

            StringBuilder str = new StringBuilder();

            l("bulk transfer thing: " + conn.bulkTransfer(epIN, buffer, 38400, 1000));

            if (conn.bulkTransfer(epIN, buffer, 38400, 1000) > 0 ) {
                l("bulk transfer is success");
                for (int i = 2; i < 64; i++) {
                    if (buffer[i] != 0) {
                        str.append((char) buffer[i]);
                    } else {
                        l(str);
                        break;
                    }
                }

            }
            // this shows the complete string
            l(str);


            if (mStop) {
                mConnectionHandler.onUsbStopped();
                return;
            }
             l("sent " + counter);
                counter++;
                counter = (byte) (counter % 16);
        }

    }
}

// END MAIN LOOP
private BroadcastReceiver mPermissionReceiver = new PermissionReceiver(
        new IPermissionListener() {

            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() + " >==<");
}

谁能告诉我需要做出哪些改变？提前谢谢。

Answer 1

有几个问题。

我认为注释掉的行就是你遇到问题的地方。您可能希望重新格式化代码缩进并提供更多信息。无论如何，假设您的问题在这里发生：

byte counter=0;
//conn.bulkTransfer(epOUT, new byte[]{msData}, 1, 0);

我看到的直接问题 - epOut，您要向其发送数据的端点为空。所以当然会失败。你把数据发送到什么都没有。我按照您发布到您复制的示例代码的链接，他们有一行显示：

epOUT = usbIf.getEndpoint(i);

我强烈建议您首先确保在开始进行更改之前了解原始代码或让它在您自己的程序中运行。不要只需复制上面一行代码即可“修复”您的问题。

从USB（多产）到Android设备的数据传输

1 个答案: