control transfer from host-to-device not working for LPC357 VCOM CDC device

Discussion created by lpcware Employee on Jun 15, 2016
Content originally posted in LPCWare by srinivasR on Wed Dec 02 01:25:00 MST 2015

I am struggling to understand the USB API from LPC to get the host to device vendor command transfer. With my libusbK host application, sending control command data to device , but always get stall PID. where as device to host works.

Not able to get the flow of ROM APIs to acheive my goal.  I am using the VCOM example given from LPC. Below is my code in ENDPOINT0 Handler.

static ErrorCode_t CDC_ep0_override_hdlr(USBD_HANDLE_T hUsb, void *data, uint32_t event)
else if(event == USB_EVT_SETUP && pCtrl->SetupPacket.bRequest ==BM_COMMAND_GET_STATUS_CONTROLLER )
pCtrl->EP0Data.Count=8; // send response to HOST [ DEVICE-TO-HOST] ...WOKRING
pCtrl->EP0Data.pData=(uint8_t *) buff;
ret = LPC_OK;
else if(event == USB_EVT_SETUP && pCtrl->SetupPacket.bRequest ==BM_COMMAND_SET_STAUTS_CONTROLLER )
                               // NOT CLEAR AS WHAT TO BE DONE
                                ////USBD_API->core->StatusOutStage(pCtrl); >>>> did not help?????????????????


Please advise.