The Atmel ATtiny85 Microcontroller is an 8-bit device based on the AVR enhanced RISC architecture. Being an Atmel tinyAVR device the ATtiny85 is packs performance and power efficiency into a small package, perfect for applications where space is at a premium. By executing powerful instructions in a single clock cycle the ATtiny85 achieves throughputs approaching 1 MIPS per MHz, balancing power consumption and speed.

Features:

• Support for Arduino IDE 1.0+ (OSX / Win / Linux)
• Power via USB or External Source – 5v or 7-35v (automatic selection)
• 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 (vis USI)
• PWM on 3 pins (More possible with Software PWM)
• ADC on 4 pins
• Power LED and Test / Status LED (on Pin0)

Downloads:

• ATTINY85 Datasheet