Hi all,

I have been playing around with the Microchip USB demo libraries on my PIC18F4550 and would like to know the reasons for choosing either for a USB device application.

It seems to me that CDC is used when you want a simple Virtual COM Port established, making the Host Software much simpler to create for data extraction. The disadvantage being that you need to select the COM port for each application.

On the contrary the HID is a standalone device that requires more thought when designing host software but is recognized as an HID USB device on your computer.

I am primarily interfacing my PIC18 with MATLAB and LabVIEW and the CDC seems to do the trick, but I'm wondering if it's worth the effort to make it a HID device and what benefit(s) I could gain by making the switch.

Cheers,
JP

 

Look and see what each class offers and how it may serve your needs.

 

Look and see what each class offers and how it may serve your needs.

I was just hoping someone could help to provide a brief description of what each of them does. Also, Microchip mentions "Composite" devices as well. How do CDC, HID, and composite differ from one another?

Another question I have is, what are "LibUSB", "MCHPUSB", and "WinUSB"? There are "Generic Driver Demos" for each of them, but I'm not really sure how they relate to CDC/HID/Composite.

Any help is much appreciated.

Thanks again,
JP

 

Anyone else have anything to add to this?