usb-pic problems

[jmofthenorth]

I'm communicating with a pic via a usb virtual com port and the ccs usb driver (usb_cdc.h). After loading the following code the pc will recognise the pic (loading it as a com port with the correct driver etc, but I can't seem to communicate with it if I use hyperterminal to detect an ascii message. My question is - is something wrong with my circuit or code? If the usb driver is correctly loaded and enumerated then does that indicate that both my rx and tx lines are correctly wired?

[Ttelmah]

The problem is that 'usb_enumerated', does not mean that you have a connection to a program at the other end. 'usb_enumerated', signifies the device is attached to a USB bus, which has a driver present for it.
In usb_cdc.h, you will find another call 'usb_connected', which reflects a program having opened the connection to the PC driver, which then means you can start sending data.

Best Wishes

[jmofthenorth]

Thanks Ttelmah but that doesn't seem to work. I think the chip may be locking up (although the com port is still initialised). Running a while loop toggling the output of an unused pin causes the pic to toggle the pin for a few seconds before it stops.

[peter.kinnear01]

I am having the same issue from what i read, i have the device enumerated, (using usb_cdc) and windows recognized the device and i installed the driver, the funny thing is that every 10min or so the device restarts, i am also toggling a led to see if its alive, and that seems fine, but still cant get HyperTerminal communicating with the device

please tell me if you fix this and how

thanks

[FvM]

Basically, a periodical call to usb_task() is missing in the example. I think, that it should be called also during extended wait periods.

The other point has already been said, sending data without an application connection at the PC side apparently causes the driver to stop servicing the device.