DCDC-USB on Linux

I'm trying to write some code to read voltage and ignition from the dcdc-usb powersupply from minibox. I"m using libusb 1.0 and I'm a little lost in this protocol. I seem to be able to write to it but I'm unable to read from it. I wonder if I'm sending the write message. For my test, I'm just writing a simple test for now, setting up the device, writing a "Get all values" command and then trying to read a response. Here's my code:

Code:

---

#define DCDCUSB_GET_ALL_VALUES                        0x81
#define DCDCUSB_RECV_ALL_VALUES                        0x82
#define READENDPOINT                                0x81
#define WRITEENDPOINT                                0x01

unsigned char* message = new unsigned char[1];
        message[0] = DCDCUSB_GET_ALL_VALUES;
        int transfered=0;

        int result = libusb_interrupt_transfer(psudev, WRITEENDPOINT, message, 1, &transfered, TIMEOUT);

        qDebug()<<"result:"<<result<<" transfered:"<<transfered;

        if(result == 0) //success
        {
                unsigned char *buffer = new unsigned char[500];
                result = libusb_interrupt_transfer(psudev, READENDPOINT, buffer, 500, &transfered, TIMEOUT);

                qDebug()<<"result:"<<result<<" transfered:"<<transfered;

                QByteArray reply = QByteArray::fromRawData((const char*)buffer, transfered);

                if(reply.size() && reply.at(0) == DCDCUSB_RECV_ALL_VALUES)
                {
                        double val = reply.at(3)*(float)0.1558;
                        m_voltageIn = QString("%.2f").arg(val).toDouble();

                        val = reply.at(4)*(float)0.1558;
                        m_ignition = QString("%.2f").arg(val).toDouble();

                        val = reply.at(5)*(float)0.1170;
                        m_voltageOut = QString("%.2f").arg(val).toDouble();
                }

                delete buffer;
        }

---

Here's some links to the window's source code and a "text test": http://resources.mini-box.com/online...SB-Pro-src.zip

Am i missing anything obvious?

Nagging suspicion: reply.at(0) is signed, and you're comparing it to a byte with the MSB set. I do not see your sample output in your post, but that's what strikes me.

EDIT: Don't you compile with -Wall set? :)

Output is:

result: 0 transfered 1

result: -7 transfered 0
"operation timed out"

:(

I tried switching to bulk transfers but with the same result. I don't have -Wall turned on and yes there are a bunch of warnings. I'll try to clean it up a bit, but i doubt it'll solve my issue with not being able to read frmo the device at all.

Ok... one other thing comes to mind

How do you know that data is immediately available after sending the request? What if it takes some time? Can you run a select() on libusb to let you know that data is available? Can you do send a "wait forever" command to libusb by using '0' for the timeout?

Quote:

---

Originally Posted by kshots

Ok... one other thing comes to mind

How do you know that data is immediately available after sending the request? What if it takes some time? Can you run a select() on libusb to let you know that data is available? Can you do send a "wait forever" command to libusb by using '0' for the timeout?

---

yes, passing 0 as the timeout will force it to wait forever. and no, that doesn't work. My only guess is that my command is wrong, or missing something. If i set up the usb device wrong, i shouldn't be able to even write to it should i?

Well, you apparently _did_ write to something. You may have the receive endpoint wrong, though... How do you know what you're sending is correct? Did you use a USB-sniffer of some sort with the windows drivers for the thing?

Code:

---

void HIDDcDcUsb::GetAllParams()

{

        sendMessage(DCDCUSB_GET_ALL_VALUES, 0);

}

bool HIDDcDcUsb::sendMessage(unsigned char cType, unsigned int len, ...)

{

        HArray hArray(len + 1);

        hArray.getBuf()[0] = cType;



        va_list args;

        va_start(args, len);

        unsigned int cnt = 0;

#ifdef _WIN32       

        unsigned char i = va_arg(args, unsigned char);

#else

        unsigned char i = va_arg(args, unsigned int);

#endif

        while (cnt<len)

        {

                hArray.getBuf()[1+cnt] = i;

                cnt++;

                if (cnt < len)

#ifdef _WIN32                       

                        i = va_arg(args, unsigned char);

#else

                        i = va_arg(args, unsigned int);

#endif

        }

       

        va_end(args);



        m_nError = -1;

        if (Write(&hArray))

        {

                if ((cType == DCDCUSB_MEM_READ_OUT)||(cType == DCDCUSB_MEM_ERASE)||(cType == DCDCUSB_MEM_WRITE_OUT))

                {

                        int tmout = 0;

                        while (m_nError == -1)

                        {

                                Sleep(A_SLEEP);

                                tmout++;

                                if (tmout > A_TIMEOUT) return false;

                        }

                }

                return true;

        }

        else return false;

}

bool HIDDcDcUsb::Write(HArray* mesg)

{

        m_lockWrite.lock();

        bool b = m_pParent->Write(mesg);

        m_lockWrite.unlock();



        return b;

}

///m_pParent is an HIDDevice:

bool HIDDevice::Write(HArray* mesg)

{

       

#ifdef _WIN32

        DWORD        BytesWritten = 0;

        ULONG        Result;

#else

        long        BytesWritten = 0;

        long        Result;

#endif



        unsigned short send = m_hidDescriptor->GetOUTLength(mesg->getBuf()[0]);

        //if (mesg->length() == 1) send = 1;



        unsigned char* buf = new unsigned char[send];

        memset(buf, 0, send);

        memcpy(buf, mesg->getBuf(), mesg->length());



#ifdef _DEBUG

        if (buf[0]!=0x81)

        {

                TRACE("TX[%d]:",send);

                for (unsigned int i=0;i<send;i++)

                        TRACE("%02X ",buf[i]);

                TRACE("\n");

        }

#endif



#ifdef _WIN32

        Result = WriteFile

                (m_WriteHandle,

                buf,

                send,

                &BytesWritten,

                NULL);

#else

        Result = write(m_WriteHandle, buf , send);

        BytesWritten = Result;

#endif



        if (Result <= 0)

        {

                DWORD err = GetLastError();

#ifdef _DEBUG

                TRACE(">>>TX[ERR=%d(%d)]\n",err,send);

#endif

                if (err == ERROR_DEVICE_NOT_CONNECTED)

                {

                        if (m_bOpened)

                        {

                                m_bOpened = false;

                                if (m_pParser)

                                        m_pParser->Disconnected();

                        }

                }



                delete buf;

                return false;

        }

        else

        {

                delete buf;

                return true;

        }

        return true;

}

---

I can't read much of that... this board's code tags seem to be broken, the horizontal scroll bar is all the way at the bottom of the box

Quote:

---

Originally Posted by kshots

Well, you apparently _did_ write to something. You may have the receive endpoint wrong, though... How do you know what you're sending is correct? Did you use a USB-sniffer of some sort with the windows drivers for the thing?

---

I got the send and receive endpoints from lsusb -v.

G'Day tripzero,
Did you get this working?
Rgds,
Ben