The AT90USBKEY is a low-cost demonstration board based on the AT90USB1287 microcontroller. It allows the quick evaluation of AVR microcontrollers and the AT90USB family. The key simply connects to the USB port of a personal computer to retrieve on-board documentation and run AVR programs. Designers can either run demonstration programs or their own application. It also allows hardware developments by giving access to the JTAG port and all the IOs of the microcontroller. An external power supply can be used for USB host or stand-alone operation.