Start Here

New to the ATtiny85? Start here.

The ATtiny85 is an 8-pin microcontroller from Microchip (originally Atmel). It costs about a dollar, runs for years on a coin cell, and is just powerful enough to be dangerous. Here’s the path I’d take.

1. Understand the chip

8KB of flash, 512 bytes of RAM, 6 usable I/O pins. That’s the whole computer. Read the Getting Started section for the full tour and the pinout cheat sheet.

2. Get your tools

You need three things:

• An ATtiny85 chip, or a Digispark board if you want USB built in.
• A programmer: an Arduino Uno running ArduinoISP works great, or grab a USBasp.
• The Arduino IDE with the ATtinyCore board package installed.

3. Blink an LED

Everyone’s first project. One LED, one resistor, five lines of code. If it blinks, your toolchain works and you’re in business.

4. Learn to sip power

The ATtiny85’s superpower is sleep modes. A coin cell can run your project for years if you learn to put the chip to sleep between jobs. The Programming section covers this in depth.

5. Build something real

Browse Projects for complete weekend builds: parts lists, wiring, and code included. Pick one that makes you grin and build it.