Features Support for theIDE 1 0 OSX Win Linux Power via USB or External Source 5V or 7 35V automatic selection On board 500ma 5V RegulatorBuilt in USB and serial debugging 6 I O Pins 2 are used for USB only if your program actively communicates over USB otherwise you can use all 6 even if you are programming via USB 8k Flash Memory about 6K after bootloader I2C and SPI vis USI PWM on 3 pins more possible with Software PWM ADC on 4 pinsPower LED and Test Status LED on Pin0 Weight 4gPackage included 3 x Development Board