It is ideal for small Arduino projects.
It can be programmed to imitate keyboard to play tricks on friends.
Power via USB or External Source – 5V or 7 -35V
On-board 500ma 5V Regulator
Built-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
PWM on 4 pins
ADC on 3 pins
Power LED and Test/ Status LED (on Pin0)
Please load drivers and download DIGISTUMP library.
Tested on Arduino IDE 1.6.5 and higher
Follow Link –