This schematics of a standard ISP programmer for AVR chips, except that it includes a USB interface-This is schematics of a standard ISP programmer for AVR chips, except that it includes a USB interface

USBasp is a USB in-circuit programmer for Atmel AVR controllers. It simply consists of an ATMega88 or an ATMega8 and a couple of passive components. The programmer uses a firmware-only USB driver, no special USB controller is needed.