ex_usb_serial example for Microchip PICDEM FS USB demo board

[stod]

Hi all,

I am relatively new to USB and am having problems running the ex_usb_serial example with the Microchip PICDEM FS USB demo board (the 18F45K50 version).
When I plug the board into my PC, the device is recognised ok as a 'CCS USB to UART' COM9 port and USB enumeration is successful as indicated by LED 1. When I open the 2 hyperterminals (COM1 and COM9) as described in the example, LEDs 2 and 3 both appear to indicate setup successfully. However, none of the setup messages appear in either of the hyperterminals, nor does typing a character in COM1 appear on COM9.

The only part of the code I have slightly modified to get any of it working was to add the following hardware and config definitions into ex_usb_common.h for my specific dev board. (the PIC18F45K50 uses its own internal FRC (Fast RC) oscillator
running at 16 MHz along with a 3X PLL to achieve the required 48 MHz).

[Ttelmah]

Key thing missing. You need to turn on ACT.

You can't actually run the USB directly from the internal 16MHz clock. It isn't accurate enough. What ACT does, is automatically synchronise the internal clock to the clock on the USB bus when you connect, so the clock becomes based on the USB clock. You need to add ACT=USB to the clock setting, which then makes this happen.

Also, since you are using setup_oscillator, on the next line add:
setup_act(ACT_ENABLED | ACT_TUNED_TO_USB);

to ensure it is left on after the oscillator changes.

[stod]

Many thanks for your help.

Unfortunately I am still having the same problem. I added/amended the following code as suggested.

[Ttelmah]

Start by doing some debugging. Check that your COM3 to the PIC is working, Forget USB till you are sure you can send and receive data on this.

You seem to have misunderstood slightly. The 'setup_oscillator' line goes in your code, not in the chip setup.

So the layout needs to be: