The Micro Digispark whose programming port is micro USB interface is an Attiny85 based microcontroller development board and it is similar to the Arduino line,

only cheaper, smaller, and a bit less powerful. With a whole host of shields to extend its functionality and the ability to use the familiar Arduino IDE the Digispark is a great way to jump into electronics,

or perfect for when an Arduino is too big or too much.

Features:

1. Support for the Arduino IDE 1.0+ (OSX/Win/Linux).

2. Power via micro USB or External Source 5V or 7-15V (12V or less recommended, automatic selection).

3. On-board 100mA 5V Regulator.

4. 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)

5. 8k Flash Memory (about 6k after bootloader)

6. I2C and SPI (via USI)

7. PWM on 3 pins (more possible with Software PWM)

8. ADC on 4 pins 9. Power LED and Test/Status LED