Archive for the ‘bootloader’ tag
The Arduino boards mainly use Atmega8 or ATmega168 controllers. For most of the projects and boards I have been working with in the last years, I have been using mega32 (more memory, more IO). In order to make use of the excellent Arduino resources, making my boards Arduino Compatible seems a logical choice. First thing to do was to rewrite the bootloader. In the following ZIP file you’ll find the modified source (untidied, but working) for an Atmega32 runnning at 16MHz. Also the modified ‘boards.txt’ file that resides in your Arduino hardware directory is in the ZIP. bootloader sources.
The bootloader can be compiled using the makefile in the zip archive, simply typing make in a console (from the correct directory, with correct path settings. I have WINavr as main avr compiler on my system)
In order to make code examples work, a re-mapping of input- and output pins is necessary. IN the discussion on the Arduino forum files where posted with a suggested re-mapping. (unfortunately they didn’t rewrite the bootloader for ATmega32, so I had to do that) I have tested uploading a serial-port example and a simple blinky, using the pin-mapping from AndreS from robotcraft.ca. Their arduino mega32 mapping sources have been posted in above forum. Overwriting the files with same names in hardware/cores/arduino directory does the trick.
I also recompiled bootloaders for other boards with ATmega8 running at 8MHz, see a page on http://www.edwindertien.nl/interactivos/index.html
Unfortunately the bootloader is rather large (2k). For an educational platform (MasterClass robot) we have been using a smaller bootloader (512K) which is AVR911 appnote compatible. (also using AVRdude to do the programming). More on this (mega32) platform can be found on http://www.ce.utwente.nl/e13 in the folder ‘education’.
A newer discussion on avrBootloaders, including the AVRdude commands used are on the wiki.