FlexCAN usage example

#define CAN_BITRATE         (125*1000)  // 125 kHz
#define CAN_READ_INTERVAL   1000        // Set to INFINITE to wait forever for a CAN Frame
#define CAN_WRITE_INTERVAL   500

CRITICAL_SECTION gCS;
LPCWSTR DataToHexString(const PCAN_FRAME pCANFrame)
{
    static WCHAR szHexString[100];
    WCHAR szHexByte[7];
    EnterCriticalSection(&gCS);
    {
        szHexString[0] = 0;
        if (pCANFrame->btDataLen)
        {
            wsprintf(szHexByte, L"0x%02X", pCANFrame->btData[0]);
            wcscat_s(szHexString, _countof(szHexString), szHexByte);
            for (int i=1; i<pCANFrame->btDataLen; i++)
            {
                wsprintf(szHexByte, L", 0x%02X", pCANFrame->btData[i]);
                wcscat_s(szHexString, _countof(szHexString), szHexByte);
            }
        }
    } LeaveCriticalSection(&gCS);
    return szHexString;
}

DWORD WINAPI CANReadThread(LPVOID lpParameter)
{
    HANDLE hFinishEvent = (HANDLE)lpParameter;
    CAN_FRAME canFrame = {0};
    canFrame.bExtended = CAN_EXTENDED;  // Receive any extended frame
    LOGMSG(ZONE_INFO, L"CAN Read Thread initialized; waiting for %s CAN frames...\r\n", (CAN_EXTENDED == canFrame.bExtended) ? L"Extended" : L"Standard");
    do
    {
        if (ERROR_SUCCESS == FlexCANReadFrame(1, &canFrame, CAN_READ_INTERVAL, 0))
        {   // Convert data to string, copy the string and show received frame
            LPWSTR pszData = wcsdup(DataToHexString(&canFrame));
            if (canFrame.bExtended == CAN_EXTENDED)
                LOGMSG(ZONE_INFO, L"Read CAN frame with ID 0x%08X, Data: %s\r\n", canFrame.ui32ID, pszData);
            else
                LOGMSG(ZONE_INFO, L"Read CAN frame with ID 0x%03X, Data: %s\r\n", canFrame.ui32ID, pszData);
            // Clean up
            free(pszData);
        }
    } while (WAIT_TIMEOUT == WaitForSingleObject(hFinishEvent, 0));

    return 0;
}

int _tmain(int argc, _TCHAR* argv[])
{
    // Register with debug subsystem
    RETAILREGISTERZONES(NULL);

    InitializeCriticalSection(&gCS);

    HANDLE hFinishEvent = NULL;
    HANDLE hReadThread = NULL;
    for (;;)
    {   // Use loop for easy break-out error handling
        if (!FlexCANInit(1))
            break;

        DWORD dwBitrate = CAN_BITRATE;
        if (!FlexCANSetBitrate(1, &dwBitrate))
            break;
        LOGMSG(ZONE_INFO, L"Bitrate set to %d (requested %d)\r\n", dwBitrate, CAN_BITRATE);

        hFinishEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
        if (!hFinishEvent)
            break;

        // Create the read thread that will receive all CAN Frames
        hReadThread = CreateThread(NULL, 0, CANReadThread, (LPVOID)hFinishEvent, 0, NULL);
        if (!hReadThread)
            break;

        // Some time to see CAN Frames coming in
        Sleep(10000);

        CAN_FRAME canFrame = {0};
        for (int i=0; i<10; i++)
        {   // Send a couple of frames at highest priority (0)
            canFrame.bExtended = CAN_EXTENDED;
            canFrame.btData[0] = 0x10;
            canFrame.btData[1] = 0x11;
            canFrame.btData[2] = 0x12;
            canFrame.btDataLen = 3;
            canFrame.ui32ID = 0x12345678;
            DWORD dwRet = FlexCANWriteFrame(1, CAN_DATA, CAN_TXNOW, 0, &canFrame, 500);
            LOGMSG(ZONE_INFO, L"Frame with ID 0x%08X and data %s sent. Result: %d\r\n", canFrame.ui32ID, DataToHexString(&canFrame), dwRet);
            Sleep(CAN_WRITE_INTERVAL);
        }

        // Signal read thread to finish
        SetEvent(hFinishEvent);
        if (WAIT_OBJECT_0 != WaitForSingleObject(hReadThread, CAN_READ_INTERVAL*2))
            TerminateThread(hReadThread, 0);

        // And wait for a frame with ID 0x12345678 for 10 seconds (no other CAN frames are accepted during this time)
        canFrame.bExtended = CAN_EXTENDED;
        canFrame.ui32ID = 0x12345678;
        LOGMSG(ZONE_INFO, L"Waiting for extended frame with ID 0x%08X...\r\n", canFrame.ui32ID);
        DWORD dwRet = FlexCANReadFrame(1, &canFrame, 10000, 0x1FFFFFFF);
        LOGMSG(ZONE_INFO, L"Specific FlexCANReadFrame result: %d\r\n", dwRet);
        if (ERROR_SUCCESS == dwRet)
            LOGMSG(ZONE_INFO, L"Read CAN frame with ID 0x%08X, Data: %s\r\n", canFrame.ui32ID, DataToHexString(&canFrame));

        // Now read any frame (ui32IDMask set to 0)
        LOGMSG(ZONE_INFO, L"Waiting for extended frame with any ID...\r\n");
        dwRet = FlexCANReadFrame(1, &canFrame, 10000, 0);
        LOGMSG(ZONE_INFO, L"Unspecific FlexCANReadFrame result: %d\r\n", dwRet);
        if (ERROR_SUCCESS == dwRet)
        {   // Show received frame
            if (canFrame.bExtended == CAN_EXTENDED)
                LOGMSG(ZONE_INFO, L"Read CAN frame with ID 0x%08X, Data: %s\r\n", canFrame.ui32ID, DataToHexString(&canFrame));
            else
                LOGMSG(ZONE_INFO, L"Read CAN frame with ID 0x%03X, Data: %s\r\n", canFrame.ui32ID, DataToHexString(&canFrame));
        }

        // Now transfer a whole bunch of messages in one go
        CAN_TRANSFER_BLOCK canBlock;
        canBlock.dwNumPackets = 32;
        canBlock.pCANPackets = new CAN_PACKET[canBlock.dwNumPackets];
        if (canBlock.pCANPackets)
        {
            for (DWORD i=0; i<canBlock.dwNumPackets; i++)
            {   // Init packets; data from max to 0
                canBlock.pCANPackets[i].bRemote = CAN_DATA;             // Data frame
                canBlock.pCANPackets[i].btIndex = 0xFF;                 // Let driver find a free message buffer
                canBlock.pCANPackets[i].btPriority = 0;                 // Highest priority
                canBlock.pCANPackets[i].bTxOnRemoteRx = CAN_TXNOW;      // Transfer immediately
                canBlock.pCANPackets[i].bWrite = CAN_WRITE;             // We want to write this frame
                canBlock.pCANPackets[i].canFrame.bExtended = CAN_STANDARD;  // Standard address (11 bit)
                canBlock.pCANPackets[i].canFrame.btData[0] = (BYTE)(0xFF - (i*(256/canBlock.dwNumPackets)));
                canBlock.pCANPackets[i].canFrame.btDataLen = 1;         // 1 byte data
                canBlock.pCANPackets[i].canFrame.ui32ID = 0x123;        // Address
                canBlock.pCANPackets[i].dwTimeout = 100;                // Write timeout
            }
            BOOL bRet = FlexCANTransfer(1, &canBlock);
            LOGMSG(ZONE_INFO, L"FlexCANTransfer result: %s\r\n", bRet ? L"TRUE" : L"FALSE");
            for (DWORD i=0; i<canBlock.dwNumPackets; i++)
                LOGMSG(ZONE_INFO, L"Individual transmit %d transmit result: %d\r\n", i, canBlock.pCANPackets[i].dwError);
        }

        // Now write a frame after receiving a remote request with the same ID
        canFrame.bExtended = CAN_EXTENDED;
        canFrame.btData[0] = 0x12;
        canFrame.btData[1] = 0x11;
        canFrame.btData[2] = 0x10;
        canFrame.btDataLen = 3;
        canFrame.ui32ID = 0x7654321;
        LOGMSG(ZONE_INFO, L"Waiting for remote request with ID 0x%08X...\r\n", canFrame.ui32ID);
        dwRet = FlexCANWriteFrame(1, CAN_DATA, CAN_TXONREMOTERX, 0, &canFrame, 10000);
        LOGMSG(ZONE_INFO, L"Frame with ID 0x%08X and data %s sent. Result: %d\r\n", canFrame.ui32ID, DataToHexString(&canFrame), dwRet);

        // Always exit out of loop
        break;
    }

    //Clean up
    FlexCANDeinit(1);

    if (hFinishEvent)
        CloseHandle(hFinishEvent);
    if (hReadThread)
        CloseHandle(hReadThread);

    DeleteCriticalSection(&gCS);

    return 0;
}