Arduino with ATmega328

ATmega328P chips are now available in the webstore, unprogrammed for $5.25 or bootloaded for $6.25.

The Arduino is based around a microcontroller made by Atmel called the AVR line. This controller contains all the code for your sketches, the code for the bootloader, and a small microprocessor with RAM to run them.

In the beginning, the Arduino project centered around the ATmega8 with 8KB of flash, 1KB of RAM, and 512B of EEPROM, later (many NGs, all Diecimila, and some Duemilanove boards) this was upgraded to the ATmega168 with 16KB of flash. Recently Atmel has introduced the ATmega328P with 32KB of flash, 2KB of RAM, and 1KB of EEPROM.

Originally, the ATmega328 was scarce and Arduino support was created and maintained by a selection of open-source hardware hackers. Since Arduino 13, ATmega328 support has been included in the main-stream IDE and, since late February 2009, official Arduinos have been shipping with ATmega328s installed from almost all resellers.

The ATmega328 contains twice as much memory and storage compared to the ATmega168 and it has the same physical design (the same pins in the same places) and mostly the same macro-architecture (the same peripherals) so code runs almost without change from the ATmega168 to the ATmega328. All these details are handled by the Arduino IDE so the ATmega328 functions just like a larger ATmega168. It does, however, run just as fast as the ATmega168, no faster.

It's like upgrading the hard drive and RAM in your computer, all at once.

Current Arduino Duemilanove boards have included ATmega328 chips since late February. You can buy Arduinos from official Arduino distributors. If in doubt, ask the distributor if you their boards include ATmega328 chips.

Many off-shoot boards (Freeduinos, etc) are being upgraded to ATmega328 chips, if in doubt, ask.

If you already have an Arduino or Freeduino, all you need is an upgraded chip. Most resellers of Arduino related hardware sell upgrade chips. All you need to do is pop out the old ATmega168 or ATmega8 and pop in the new ATmega328.

You can follow the directions on the upgrade page.

In particular, we carry ATmega328 upgrade chips over in the Fundamental Logic store.

If you're buying an ATmega328 as an upgrade for your Arduino, make sure it includes the Arduino bootloader. In particular, this means you can't just buy an ATmega328 from Mouser or Digikey. (The bootloader helps you download your sketches to the Arduino.)