[quote user="David Pfaltzgraff"]Under the failed condition, when I click the HT connect icon, I get a pop-up window that says "Cannot connect to COM9" which is where my device normally shows up.[/quote]
Cliking at the connect icon, HyperTerminal puts a couple of Requests to the device,
- Set_Line_Coding
- Get_Line_Coding
- Set_Control_Line_State
Get a valid clue, using a USB sniffer,
a) Confirm the request, on which an error occurs.
OR
b) Check the data (line coding setting) returned by Get_Line_Coding, if it would match to those of Set_Line_Coding just before, or not.
USB sniffers
- Free USB Device Monitor http://www.free-usb-device-monitor.com/
- USBlyzer(33 days trial) http://www.usblyzer.com/
etc
The process of these Requests lives in HandleRequests() of the usbdcdc.c
StellarisWare\usblib\device\usbdcdc.c
HandleRequests(void *pvInstance, tUSBRequest *pUSBRequest)
{
...
switch(pUSBRequest->bRequest)
{
...
case USB_CDC_SET_LINE_CODING:
case USB_CDC_GET_LINE_CODING:
case USB_CDC_SET_CONTROL_LINE_STATE:
Using debugger, trace the reason why the error, found in the sniffer, occurs.
To run source code debug, you have to add usbdcdc.c to your project, explicitly.
Tsuneo