From arduino to attiny85 – shrink that project

After spending a year make arduino projects I wanted to get my hands dirty in the world of Attiny’s and in the process shirking one of my projects.

So lets get started first you need to pick your microcontrollor, I desided to start with the attiny85 because you can program it from an ardiuno so no need for extra hardware. Here is how you need to wire up your attiny85 on a breadboard


  • Arduino pin 13 – Attiny85 pin 7
  • Arduino pin 12 – Attiny85 pin 6
  • Arduino pin 11 – Attiny85 pin 5
  • Arduino pin 10 – Attiny85 pin 1
  • Arduino 5v pin – Attiny85 pin 8
  • Arduino ground –  Attiny85 pin 4

Once that is all set up you need to download the Attiny85 cores to add to your arduino IDE. There is lots of dated dead link to a files on here but dont panic someone else has picked up the tourch. You will need to download the file arduino 1.0 if your using arduion IDE version 1.xx which is what your probely using

arduino-tiny - ATtiny core for Arduino - Google Project Hosting - Chromium_013

You will need to firstly close arduino IDE then locate your arduino sketch folder, this is where you the arduino IDE keeps all the sketches you make. inside this folder you will need to make a folder names ‘hardware’ without the quote marks. Next up unzip the file you downloaded and move the folder to the hardware folder you just made.

If you read the readme file it will ask you to open the Prospective Boards.txt file and copy what you need from the file to a new file call boards.txt or you could just rename Prospective Boards.txt to boards.txt .

Right time to reopen arduino IDE and set up your arduino, firstly you need to upload the arduinoSPI to your arduino


Next up you will need to change your board to be ATiny85 @8MHz (internal oscillator,BOD disabled)


After a bit of research I found that if your going to run your project off a wall wart then you want to run it at 8MHz or that your project calls to be ran at 8MHz. If your concerned aboiut battery life then run it at 1MHz

Next select the programmer, as were using arduino to program it then we select Arduino as ISP


Then you need to burn the bootloader


Now your all done you can upload a sketch. An easy one is open up the blink sketch from the example and change the ledpin from 13 to 0. Here is how you need to wire up the breadboard


Just connect the LED long pin to pin 5 which is equivalent to arduino pin 0 and the short LED pin to ground with a 220 ohm resistor

Now you need to upload it and if you have done it all right the led should blink like it normaly does on an arduino

One response to “From arduino to attiny85 – shrink that project

  1. Pingback: One button TV remote (Attiny85/Arduino) | Facelesstech·

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