In this instructable I will show you how to program AT Tiny chips as they are cheaper than arduino's and they are much smaller.

Step 1: Parts and Tools

Here are the parts and tools needed to make this project:
At tiny 85 or 45
Arduino uno
Wire
Computer with arduino IDE
Breadboard

Step 2: Get at Tiny Files

Download these files:
https://github.com/damellis/attiny/

This is for Mac:
Go to : go : documents: open the arduino folder: make a folder called: hardware:open hardware folder: drag the at tiny files into the folder.
This should work as it worked for me.

Step 3: Wire Circuit

Connect the arduino to the attiny:
Arduino 5 volts to ATtiny pin 8.
Arduino ground to ATtiny pin 4.
Arduino pin 10 to ATtiny pin 1.
Arduino pin 11 to ATtiny pin 5.
Arduino pin 12 to ATtiny pin 6.
Arduino pin 13 to ATtiny pin 7.

Step 4: Program Arduino

Select arduinoISP sketch for on the examples menu then upload the sketch to the arduino.
Now your arduino can program other chips
Most people use a 10 uf capacitor but I found that I didn't need it. When you upload the ISP code make sure that that you have selected AVRISP mkll as the programmer under tools --> programmer.

Step 5: Upload Sketch

Upload the sketch that you want on the at tiny but you will get an error if your code contains any serial commands so just comment them out. Make sure to change the arduino board to the at tiny 85 1 MHz or whatever your chip is. Make sure that the programmer is "Arduino as ISP".

Step 6: Done

If you had problems doing this like you get an error just comment below and I can help you. If it worked congrats you have finished this instructable. Please vote for this instructable in contests or favourite and subscribe.