Hi
I am trying to get multiple virtual COM ports on a single LPC11U35.
Windows detects the device, agrees that there are 2 COM ports (and a mouse, which is rudimentary from the example code). The COM port that came with the example works well. I modified the code to get the second one working, but it fails at configuration (opening the port). The example project I used was "nxp_lpcxpresso_11u14_usbd_lib_composite" from "lpcopen_v2_00a_lpcxpresso_nxp_lpcxpresso_11u14.zip"
Using breakpoints, I looked up the path what a working port should follow. I have determined that when opening the port, the working one goes all the way to its "VCOM_SetLineCode" function, however the failing one does not get past "USB_EndPoint0" ("USB_EvtOutHandler" never gets called). Here is a screenshot of the working chain:
Parts of code that may be of interest:
From main:
ret = USBD_API->hw->Init(&g_hUsb, &desc, &usb_param);
if (ret == LPC_OK) {
ret = Mouse_Init(g_hUsb, (USB_INTERFACE_DESCRIPTOR *) find_IntfDesc(desc.high_speed_desc, USB_DEVICE_CLASS_HUMAN_INTERFACE), &usb_param.mem_base, &usb_param.mem_size);
if (ret == LPC_OK) {
/* Init VCOM interface */
ret = vcom_init_multi(g_hUsb, &desc, &usb_param, &g_vCOM, USB_CDC_IN_EP, USB_CDC_OUT_EP);
if (ret == LPC_OK) {
ret = vcom_init_multi(g_hUsb, &desc, &usb_param, &g_vCOM2, USB_CDC2_IN_EP, USB_CDC2_OUT_EP);
if (ret == LPC_OK) {
/* enable USB interrrupts */
NVIC_EnableIRQ(USB0_IRQn);
/* now connect */
USBD_API->hw->Connect(g_hUsb, 1);
}
}
}
}
Initialization function:
ErrorCode_t vcom_init_multi(USBD_HANDLE_T hUsb, USB_CORE_DESCS_T *pDesc, USBD_API_INIT_PARAM_T *pUsbParam, VCOM_DATA_T *vCOMused, uint8_t ep_in, uint8_t ep_out){
int static comPortCounter = 0;
comPortCounter++;
DEBUGLED00_SETOUTPUT;
DEBUGLED00_OFF;
USBD_CDC_INIT_PARAM_T cdc_param;
ErrorCode_t ret = LPC_OK;
uint32_t ep_indx;
VCOM_DATA_T *localVCOM = vCOMused;
//g_vCOM.hUsb = hUsb; //example what was before for next line
localVCOM->hUsb = hUsb;
memset((void *) &cdc_param, 0, sizeof(USBD_CDC_INIT_PARAM_T));
cdc_param.mem_base = pUsbParam->mem_base;
cdc_param.mem_size = pUsbParam->mem_size;
cdc_param.cif_intf_desc = (uint8_t *) find_IntfDesc(pDesc->high_speed_desc, CDC_COMMUNICATION_INTERFACE_CLASS);
cdc_param.dif_intf_desc = (uint8_t *) find_IntfDesc(pDesc->high_speed_desc, CDC_DATA_INTERFACE_CLASS);
if(comPortCounter==1) cdc_param.SetLineCode = VCOM_SetLineCode;
else cdc_param.SetLineCode = VCOM_SetLineCode2;
ret = USBD_API->cdc->init(hUsb, &cdc_param, &(localVCOM->hCdc));
if (ret == LPC_OK) {
/* allocate transfer buffers */
localVCOM->rx_buff = (uint8_t *) cdc_param.mem_base;
cdc_param.mem_base += VCOM_RX_BUF_SZ;
cdc_param.mem_size -= VCOM_RX_BUF_SZ;
/* register endpoint interrupt handler */
ep_indx = (((ep_in & 0x0F) << 1) + 1);
if(comPortCounter==1) ret = USBD_API->core->RegisterEpHandler(hUsb, ep_indx, VCOM_bulk_in_hdlr, localVCOM);
else ret = USBD_API->core->RegisterEpHandler(hUsb, ep_indx, VCOM_bulk_in_hdlr2, localVCOM);
if (ret == LPC_OK) {
/* register endpoint interrupt handler */
ep_indx = ((ep_out & 0x0F) << 1);
if(comPortCounter==1) ret = USBD_API->core->RegisterEpHandler(hUsb, ep_indx, VCOM_bulk_out_hdlr, localVCOM);
else ret = USBD_API->core->RegisterEpHandler(hUsb, ep_indx, VCOM_bulk_out_hdlr2, localVCOM);
}
/* update mem_base and size variables for cascading calls. */
pUsbParam->mem_base = cdc_param.mem_base;
pUsbParam->mem_size = cdc_param.mem_size;
}
return ret;
}
SetLinecode functions:
/* Set line coding call back routine */
static ErrorCode_t VCOM_SetLineCode(USBD_HANDLE_T hCDC, CDC_LINE_CODING *line_coding)
{
//THIS FUNCTION GETS CALLED WHEN COMPORT OPENS
VCOM_DATA_T *pVcom = &g_vCOM;
DEBUGLED00_ON;
/* Called when baud rate is changed/set. Using it to know host connection state */
pVcom->tx_flags = VCOM_TX_CONNECTED; /* reset other flags */
return LPC_OK;
}
static ErrorCode_t VCOM_SetLineCode2(USBD_HANDLE_T hCDC, CDC_LINE_CODING *line_coding)
{
//This function does not get called when comport opens, for some reason!?
VCOM_DATA_T *pVcom = &g_vCOM2;
DEBUGLED00_ON;
/* Called when baud rate is changed/set. Using it to know host connection state */
pVcom->tx_flags = VCOM_TX_CONNECTED; /* reset other flags */
return LPC_OK;
}
A section from app_usbd_cfg.h
/* HID In/Out Endpoint Address */
#define HID_EP_IN 0x81
#define USB_HID_IF_NUM 0
/** Interval between mouse reports expressed in milliseconds for full-speed device. */
#define HID_MOUSE_REPORT_INTERVAL_MS 10
/* bInterval value used in descriptor. For HS this macro will differ from HID_MOUSE_REPORT_INTERVAL_MS macro. */
#define HID_MOUSE_REPORT_INTERVAL 10
/* Manifest constants defining interface numbers and endpoints used by a
CDC class interfaces in this application.
*/
#define USB_CDC_CIF_NUM 3
#define USB_CDC_DIF_NUM 4
#define USB_CDC_IN_EP 0x81 //0x81 is EP1_IN
#define USB_CDC_OUT_EP 0x01 //0x01 is EP1_OUT?
#define USB_CDC_INT_EP 0x82
//added to try to get second vcom
#define USB_CDC2_CIF_NUM 1
#define USB_CDC2_DIF_NUM 2
#define USB_CDC2_IN_EP 0x83
#define USB_CDC2_OUT_EP 0x03
#define USB_CDC2_INT_EP 0x84
(NB, I see that mouse and one CDC share the same EP_IN value, however this is the one that works. As I understand, they should not share the EP value)
Hopefully this is enough information. Please let me know if something else could be of assistance. I hope someone else has stumbled across this issue and can direct me forward.
Hi Jens Dender,
After dig deeper into the issue, I think the LPC11U35 can't achieve the application: HID +CDC+CDC, as the LCP11U35 has the limitation of the endpoint number (Fig 1).
So I'd highly recommend you to choose the LPC176x/5x instead of the LPC11U35 and LPC176x/5x can support 16 endpoints.
Fig 1
Hope this is clear.
Have a great day,
Ping
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Hi Jens Dender,
After dig deeper into the issue, I think the LPC11U35 can't achieve the application: HID +CDC+CDC, as the LCP11U35 has the limitation of the endpoint number (Fig 1).
So I'd highly recommend you to choose the LPC176x/5x instead of the LPC11U35 and LPC176x/5x can support 16 endpoints.
Fig 1
Hope this is clear.
Have a great day,
Ping
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------
