USBtiny is a software implementation of the USB low-speed protocol for the Atmel ATtiny microcontrollers.
http://www.xs4all.nl/~dicks/avr/usbtiny/index.html
With the continuous decrease in the use of COM Port devices and COM Ports itselt, the need to migrate to the USB has become increasingly important. Just take a look at the laptop PCs nowadays, it is a miracle if you can even find just 1 COM Port on it.
http://www.geocities.com/dariuskrail20/USBUSART.html
Here is how to interface a PIC18F452 to a PC via the USB port. The PIC captures the ambient temperature with a SPI sensor TC77. Its value is then transferred to the USB-interface.
http://www.techdesign.be/projects/017/017.htm
At PC-accessible USB receptacle and at the peripheral receptacle, the USB signal has the format of differential-NRZI (nonreturn-to-zero-inverted) code. After conversion (with a simple circuit or test probes) of this differential to single-ended signal, th
http://www.edn.com/article/CA193196.html
Interface for Full Speed USB Bus use and EZUSB ActiveX container
http://www.braintechnology.de/braintechnology/en/usb_interface.html
EDN's hands-on USB project gets the bus under control
http://www.edn.com/archives/1997/061997/13df_01.htm
links to information about USB and sample code to download
http://www.lvr.com/usb.htm
description, organizations, IC manufacturers, connector specifications, cable and software
http://www.interfacebus.com/Design_Connector_USB.html