Problems with USB / 18F4550

[jaderd]

I dont understand why the windows on all tests install the same generic driver...

[jaderd]

I would like to know if is necessary using two pullup resistor of D+ and D- to Vcc, or internal pullups, or is not necessary there resistors?

[Ttelmah]

Not necessary, if you have the internal resistors enabled (default for the standard demos). This is down to the fuses selected.

Best Wishes

[jaderd]

Then what is the problem on my USB communication?

[Ttelmah]

Without going right through your hardware, difficult to know. Common faults:
1) Ringing problems on the USB lines, if the PCB tracks to the D+/D- connections, are either overlength, or have odd loadings.
2) Poor local voltage regulation/smoothing on the PIC.
3) Crystal that has the wrong loading capacitance, or too much parasitic capacitance. USB requires the oscillator to be within 1 part in 10^5. Many USB circuits fail because this is not met.
4) I would add the Vusb sense line, and enable this. It allows the drivers to wake up much more cleanly, and increases the probability of good initialisation.
5) Problems with line termination, if the USB bus is long. The transceiver in the PIC, is quite 'fussy' in some versions. Adding small series resistors to the D+ and D- lines can help (typicall < 50R).
6) Ground loop problems with your power supply and the PC. Is your supply genuinely floating, and the circuit grounded through the USB bus?. This is the most reliable configuration.
7) Double check that you have the D+, and D- connections the right way round. Partial connection will often take place if they are reversed....
8) If you have once 'failed' to connect, it is well worth manually uninstalling the failed installation, or the OS will keep picking up the wrong installation, again and again....
9) Interference/crosstalk on the USB lines, again down to PCB layout.

Best Wishes

[jaderd]

Someone have a functional code programed by self with USB in PIC18F4550, or equivalent, for send to me? I need help!

Thanks in advance.

[jaderd]

???

[Ttelmah]

You already have such a program. ex_usb_serial.c, for example _does work, with your compiler version_. Setup the hardware to match the notes in the file, and it runs....

Best Wishes