## Optiboot Bootloader for Arduino and Atmel AVR ##

![http://optiboot.googlecode.com/files/optiboot.png](http://optiboot.googlecode.com/files/optiboot.png)

Optiboot is an easy to install upgrade to the Arduino bootloader within Arduino boards. It provides the following features:

  * Allows larger sketches. Optiboot is a quarter of the size of the default bootloader, freeing 1.5k of extra space.
  * Makes your sketches upload faster. Optiboot operates at higher baud rates and has streamlined programming.
  * Adaboot performance improvements. Optiboot runs your sketches sooner, with no watchdog issues.
  * Compatible with 168 and 328 Arduinos including Lilypad, Pro, Nano
  * Believed to work with ATmega1280 ("Mega"), ATmega644 ("Sanguino"), and ATmega1284 ("Mighty")
  * Supports several additional AVR chips (ATmega88, ATmega32)

Optiboot is now installed by default on the Arduino Uno. It can be installed on all older mega8, 168 or 328 based Arduinos.

## To install into the Arduino software ##
  1. Download the latest using Git or the Zip download feature of GutHub.  If you download as a zip, also extract it.
  1. You will need to be using a recent version of the [Arduino environment](http://arduino.cc), version 18 or later.
  1. Create a 'hardware' directory inside your sketches folder.
  1. Copy the optiboot directory into the hardware directory.
  1. Restart the Arduino software. New boards will appear in the Tools>Board menu.

## To burn Optiboot onto an Arduino board ##
  1. Select the appropriate Optiboot board type (or non-Optiboot if you want to change back)
  1. Connect your Arduino to an ISP programmer [[Installing]]
  1. Use the 'Burn Bootloader' item in Arduino.
  1. You can then upload sketches as normal, using the Optiboot board type.

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> Although it has evolved considerably, Optiboot builds on the original work of Jason P. Kyle (stk500boot.c), [Arduino group (bootloader)](http://arduino.cc), [Spiff (1K bootloader)](http://spiffie.org/know/arduino_1k_bootloader/bootloader.shtml), [AVR-Libc group](http://nongnu.org/avr-libc) and [Ladyada (Adaboot)](http://www.ladyada.net/library/arduino/bootloader.html).

> _Optiboot is the work of Peter Knight (aka Cathedrow). Despite some misattributions, it is not sponsored or supported by any organisation or company including Tinker London, Tinker.it! and Arduino._  
> Maintenance of optiboot was taken over by Bill Westfield (aka WestfW) in 2011.