PIC18F4550 USB CDC running creates an unknown device on PC

n-squared · Joined: 03 Oct 2006 Posts: 99

Hi
I have a PCB with a PIC18F4550 that works fine with the CCS HID demo.
When I try to use the CDC demo file (ex_usb_serial.c), I get an unknown device in Device Manager, under Other Devices called SERIAL DEMO.
This is the name specified in usb_desc_cdc.h in \drivers.
Do I need to get a VCP DLL from somewhere to get it to work?

I use CCS PCH V4.136.

Best regards
Noam
_________________
Every solution has a problem.

Ttelmah · Joined: 11 Mar 2010 Posts: 19535

When it first saw the device, it should have asked you for a driver.
This is in:

wherever_CCS_is\drivers\NT,2000,XP,VISTA,7

Just a .inf file, not a DLL. The standard CDC driver, once it is 'told' about the CCS device, does the rest.

Best Wishes

n-squared · Joined: 03 Oct 2006 Posts: 99

Hi Ttelmah

Windows did not ask me for a driver.
How do I go about forcing the driver down its throat?

Best regards
Noam
_________________
Every solution has a problem.

Ttelmah · Joined: 11 Mar 2010 Posts: 19535

If it didn't ask for a driver, then the device is not working properly. Double check things like the clock/fuses. It'll give an unrecognised device, if (for instance) the PIC is clocking at the wrong rate. Triple check that the 'common' file being loaded by the HID demo, is the same one being used by the CDC demo.
You can force a driver via device manager, but it won't work till the device is working.

Best Wishes