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Microchip USB framework problems.

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New Member
Hi all,
I have made a pcb with a 18f4550 and a few LEDs and headers.
This is my first attempt at USB, and so the board has no other purpose than just to aid learning.

The usb device im making is completely powered by the usb bus, and therefore i have got rid of the code in the framework that handles usb bus sense. As you can see from my schematic i have not included a bus sense pin.

My problem is that the device isnt recognised by the pc.
The leds flashing on the pcb, when i connect it to the pc, indicate that the microchip framework mode (usb_device_state) is set to "addressed".
It stays in this state, and windows tells me that the device is not recognised.

Also, the PID and VID of the unrecognised device are both 0000 in device manager.

I have really hit a wall here, I just dont know what im doing wrong.

Any ideas?

I used this page as a starting point, and modified the code found here

Also i have included a zipped copy of my project.

Many thanks in advance.:D


Last edited:


New Member
I changed the usb port it was on and now its installed the drivers, but windows says that the device cannot start.
Why???? stupid windows.


New Member
Yes it will... all sorts of weird problems can result.

The device sheet says the cap is mandatory but it's surprising just how many people ignore that.

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