==== Introduction  ====


The 'brains' of the Arduino is a microcontroller called an ATmega. It is a product line from [[http://www.avr.com|AVR]] (a Norweigen chip company). Just like Intel & AMD release new & better chips each year, so does AVR. The first versions of the Arduino (up to the NG) used an ATmega8 - a chip with 8K of flash memory and 1K of RAM. Then AVR released the [[http://www.adafruit.com/index.php?main_page=product_info&cPath=17&products_id=56|ATmega168]], a drop-in replacement with 16K of flash and 1K of RAM - a really big improvement! Now there is the [[http://www.adafruit.com/index.php?main_page=product_info&cPath=17&products_id=123|ATmega328]] with 32K of flash and 2K of RAM. 



Updating and replacing your Arduino is easy and painless and costs only a few dollars. Your sketches will work just as before but with a little more breathing room. 



In order to perform this upgrade you will have to either purchase [[http://www.adafruit.com/index.php?main_page=product_info&cPath=17&products_id=123|a preprogrammed chip]] or program it yourself with a [[http://www.adafruit.com/index.php?main_page=product_info&cPath=16&products_id=46|AVR programmer]] or by [[http://www.geocities.jp/arduino_diecimila/bootloader/index_en.html|'bitbanging' it]].


==== Replace the chip  ====

First, **gently **pry the Arduino microcontroller from its socket using a small flat screwdriver or similar. Try to make sure the pins dont get bent. Put it in a safe place. Preferably in an anti-static bag.    
[[http://www.ladyada.net/images/eshield/prychip.jpg|{{  http://www.ladyada.net/images/eshield/prychip_t.jpg?nolink&500x375  |}}]]



Next, prepare the new chip. The pins of ICs are a little skewed when they come from the factory, so they need to be bent in just a tiny bit, to be parallel. Grip the chip from the ends and use a table.

[[http://www.ladyada.net/images/mshield/bendchip.jpg|{{  http://www.ladyada.net/images/mshield/bendchip_t.jpg?nolink&500x367  |}}]]



Finally, replace the old chip, lining up all the pins and making sure that the notch in the chip matches the notch in the socket!


==== Download an Arduino IDE with ATmega328 compatibility  ====


[[http://code.google.com/p/arduino/downloads/list|Version 13 and up of the Arduino software supports the 328! ]]



If you purchased a chip from Adafruit that shipped before Feb 5, 2009 the chip will have the baudrate set at 19200 (same as the older Arduinos). After Feb 5 the upgrade chips were changed to 57600 baud rate (3 times faster!) in order to be compatible with new Arduinos. If you have a 19200 baud rate chip you will have difficulty uploading. Simply quit the Arduino application and edit the file in the **hardware **folder named **boards.txt** and change the line from

atmega328.upload.speed=57600



to

atmega328.upload.speed=19200



If you're having problems please try BOTH just in case!