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USB HID multiple packet problem

Trying to send an InReport > 64 bytes. Read all threads(thanks Tsuneo) but still not working. That is too say, I'm using SimpleHIDWrite as my tester, 64-byte packets work fine. If I run this code, sending a 65-byte In Report using 2-packets, I get from SimplHIDWrite "Get Report Error: CRC mismatch (17)". Any help much appreciated!

BOOL HID_GetReport (void)
{

// ReportID = SetupPacket.wValue.WB.L;
switch (SetupPacket.wValue.WB.H)
{
    case HID_REPORT_INPUT:
        //We've been asked to report, go get report and send 1st packet
        GetInReport();
        //memcpy(&EP0Buf[0],(u8*)&MyInReport[0],sizeof(MyInReport));
        //memcpy(&EP0Buf[0],(u8*)&MyInReport[0],64);
        break;
    case HID_REPORT_OUTPUT:
        return (FALSE);          // Not Supported
    case HID_REPORT_FEATURE:
        /* EP0Buf[] = ...; */
        /* break; */
        return (FALSE);          // Not Supported
 }
        return (TRUE);
}


*******************************************************************

void GetInReport (void)
{

        // Check if PBINT is pressed
        if((IOPIN0 & PBINT) == 0)
        {       //just add some data for now
                MyInReport[0] = 0xC1;
                MyInReport[1] = 0xD1;
                MyInReport[63] = 0x63;
        }
        else
        {       //just add some data for now
                MyInReport[0] = 0xC0;
                MyInReport[1] = 0xD0;
                MyInReport[63] = 0x63;
        }
        VICIntEnClr  |= 0x00400000;            // Disable USB Interrupt
        USB_WriteEP(0x81, &MyInReport[0], 64); //Send 1st packet, 64 bytes
        iNextInPacket = 1;                     //Set flag for EP1 ISR
        VICIntEnable |= 0x00400000;            // Enable USB Interrupt

}

***********************************************************************

void USB_EndPoint1 (DWORD event)
{

        switch (event)
        {
                case USB_EVT_IN:
                    if(iNextInPacket)
                    {  //OK, more data, send second packet (1-byte, total of 65-byte report)
                          iNextInPacket = 0;
                          USB_WriteEP(0x81, &MyInReport[64], 1);
                    }
                    break;
        }
}

Parents

0 Chinzei Tsuneo over 14 years ago in reply to Richard Handley

You don't touch to your MCU type number, but Keil's USB stack is almost common for various MCUs, except for the low-level routines. Get_Report process is also common. I picked up LPC17xx USBHID code here.

The problem lies in Keil's HID implementation.

USBHID example expects that the input report is loaded in InReport[] in GetInReport().
The report is copied to EP0Buf[] at HID_GetReport(), as follows.

hiduser.c

uint32_t HID_GetReport (void) {

  /* ReportID = SetupPacket.wValue.WB.L; */
  switch (SetupPacket.wValue.WB.H) {
    case HID_REPORT_INPUT:
      GetInReport();
      EP0Buf[0] = InReport;
      break;

In USB_EndPoint0(), The address of EP0Buf[] is registered to EP0Data.pData after HID_GetReport() call. And then, the stack code takes care of the rest, including multi-packets transfer.

usbcore.c

void USB_EndPoint0 (uint32_t event) {

  switch (event) {
    case USB_EVT_SETUP:
      USB_SetupStage();
      USB_DirCtrlEP(SetupPacket.bmRequestType.BM.Dir);
      EP0Data.Count = SetupPacket.wLength;     /* Number of bytes to transfer */
      switch (SetupPacket.bmRequestType.BM.Type) {
        ...
        ...
#if USB_CLASS
        case REQUEST_CLASS:
          switch (SetupPacket.bmRequestType.BM.Recipient) {
            ...
            case REQUEST_TO_INTERFACE:
#if USB_HID
              if (SetupPacket.wIndex.WB.L == USB_HID_IF_NUM) {           /* IF number correct? */
                switch (SetupPacket.bRequest) {
                  case HID_REQUEST_GET_REPORT:
                    if (HID_GetReport()) {
                      EP0Data.pData = EP0Buf;   // <----------- the problem is here
                      USB_DataInStage();                                 /* send requested data */
                      goto setup_class_ok;
                    }
                    break;

However, the size of EP0Buf[] is 64 bytes, at most. LPC17xx example sets it to 8.

usbcfg.h
#define USB_MAX_PACKET0     8

usbcore.c
uint8_t  EP0Buf[USB_MAX_PACKET0];

The implementation of Control Transfer process supports multi-packets transfer, successfully. But above HID implementation spoils it. You may improve it as follows.

hiduser.c

uint32_t HID_GetReport (void) {

  /* ReportID = SetupPacket.wValue.WB.L; */
  switch (SetupPacket.wValue.WB.H) {
    case HID_REPORT_INPUT:
        //
        // fill your_custom_buffer[] with a input report, here
        //
        EP0Data.pData = your_custom_buffer;   // pass your buffer to the stack

And comment "EP0Data.pData = EP0Buf;" line on USB_EndPoint0()

usbcore.c

void USB_EndPoint0 (uint32_t event) {
   ...
                  case HID_REQUEST_GET_REPORT:
                    if (HID_GetReport()) {
               //     EP0Data.pData = EP0Buf;  // comment this line
                      USB_DataInStage();                                 /* send requested data */

Tsuneo

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