"Host Present" Detection via LPCOpen USB Library (LPC11U68)

mattferrari — Wed, 09 Nov 2016 00:30:23 GMT

I am coding a USB MSC application and am connecting with the Host via the USB Library function call:

USBD_API->hw->Connect(g_hUsb, 1);

I would like to know if there is a facility for confirming that Host is actually present.

Is there a flag I can check, or a function I can call which can tell me if (or when) the presence (or absence) of a Host can be confirmed?

Thanks,

Matt

Re: "Host Present" Detection via LPCOpen USB Library (LPC11U68)

mattferrari — Fri, 11 Nov 2016 02:12:14 GMT

Dear NXP tech support, can you please provide an answer to this question? Thanks, Matt

Re: "Host Present" Detection via LPCOpen USB Library (LPC11U68)

jeremyzhou — Fri, 11 Nov 2016 07:03:42 GMT

Hi Matt Ferrari,

You can check the return value of the EP0 handler when USB device fail to complete the enumeration, and you can find the code above

          g_Ep0BaseHdlr = pCtrl->ep_event_hdlr[0];/* retrieve the default EP0_OUT handler */
          pCtrl->ep_event_hdlr[0] = EP0_patch;/* set our patch routine as EP0_OUT handler */‍‍

/* EP0_patch part of WORKAROUND for artf45032. */
ErrorCode_t EP0_patch(USBD_HANDLE_T hUsb, void *data, uint32_t event)
{
     switch (event) {
     case USB_EVT_OUT_NAK:
          if (g_ep0RxBusy) {
               /* we already queued the buffer so ignore this NAK event. */
               return LPC_OK;
          }
          else {
               /* Mark EP0_RX buffer as busy and allow base handler to queue the buffer. */
               g_ep0RxBusy = 1;
          }
          break;

     case USB_EVT_SETUP:     /* reset the flag when new setup sequence starts */
     case USB_EVT_OUT:
          /* we received the packet so clear the flag. */
          g_ep0RxBusy = 0;
          break;
     }
     return g_Ep0BaseHdlr(hUsb, data, event);
}‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Have a great day,
Ping

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"Host Present" Detection via LPCOpen USB Library (LPC11U68)

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Re: "Host Present" Detection via LPCOpen USB Library (LPC11U68)