Project:USBGroup/Resources

Resources.

General USB Resources.

• http://lvr.com/usb.htm is the website of USB Complete author Jan Axelson. A great place to start for anything to do with USB.
• http://www.usb.org/developers/ Resources include the full USB specification.
• http://www.usbmadesimple.co.uk/ The basics of The USB Protocol.
• http://ww1.microchip.com/downloads/en/AppNotes/91054c.pdf Useful Microchip document to help you understand USB Descriptors.

Microchip.

• http://pwc.theclarkwebsite.com/PIC18F4550usb.php How to create a really simple circuit for a PIC18F4550 HID device.
• http://eegeek.net/content/view/35/32 Understanding the Microchip USB Firmware. "The Microchip USB firmware (for the PICDEM full-speed USB demo board, but used frequently for DIY projects as well) is written and organized in a manner that it is not very easy to just take a quick look and see exactly what's going on. Everything is arranged across 9 source files, and 15 header files. There are enough subroutines to make your head spin. Things are broken down into pretty logical chunks, with an ample amount of commenting accompanying each subroutine, however it's still hard to pick out what is being run, and when. First off, you need to get an idea of the "core" execution path during normal operation, with the device already enumerated and configured and sitting there running user code and servicing requests. This description is assuming that the device is running the 'generic' class firmware, as in the Microchip firmware I started from. "
• http://www.waitingforfriday.com/index.php/Building_a_PIC18F_USB_device Building a PIC 18F device.
• http://www.connectable.org.uk/wp2/?page_id=135 An interesting project using the PIC18F4550.
• http://picspalsandgals.wordpress.com/ Some starter PIC18F4550 projects including a simple circuit diagram to show the basic connection of the PICKit3 to a 18F4550.

Tools.

• Microsoft USB Viewer - USBView is a free utility from Microsoft that displays the USB connection tree and shows the USB devices that are connected to it together with their configuration data. This is very useful for debugging USB enumeration errors. USBView runs under Windows 98, ME, 2000 and XP.
• use lsusb under Linux (with -vv to see descriptiors, you might need to run it with sudo)