Attiny85 Micro USB
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.
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