will be read-only starting December 31st, 2018. For more info please look at this Forum Post

Bootloader Development

NOTE: The contents of this page are quite outdated. For some other bootloader projects see the "Alternative Bootloaders" section of

This page is an attempt to point people to others doing bootloader development. Limor Fried (aka Lady Ada) has hacked the NG bootloader into a really universal bootloader, useful on either NG's, Diecimilas, Bare Bones Boards, Limor's Boarduino etc, etc. Brian Riley at, and Paul Badger at are all using it on currently shipping Arduino-compatibles.

The details, source and hex are here.

Limor's Adaboot has the following features:

  • Works on either NG or Diecimila type hardware (with or without auto reset).
  • Works with any version of the IDE.
  • Sketches start immediately at powerup.
  • sketches start immediately after upload.

Brian Riley has added some upload blinky feedback on pin 13, version control and its own blink scheme so it's easy to distinguish from pokier official Arduino bootloaders.