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Topic: Sparkfun has the Atmega328 in stock (Read 3134 times) previous topic - next topic


Like the title says: http://www.sparkfun.com


I know this is probably a dumb question... Can you put the Arduino bootloader on the ATMega328 and plug it into an Arduino board?

(Laugh away please... I am quite skilled in Analog electronics.)



The bootloader code must be different, to account for the change in memory configuration, and the compiler must be told to compile your sketches with this in mind, but essentially, yes.  Shortly, the new Arduino IDE 0013 will support the new chip as an alternate.


Can you put the Arduino bootloader on the ATMega328 and plug it into an Arduino board?

I did  ;)

See my bootloader application hint at http://tinyurl.com/5rfmrz

(* jcl *)


I know this is probably a dumb question... Can you put the Arduino bootloader on the ATMega328 and plug it into an Arduino board?

Please, someone, tell me if I've got any of this wrong.

First point: The new chip is pin-compatible, so, hardware-wise, upgrading a classic Arduino with a socketed processor is about as easy an upgrade as possible.

Second point: Unless you change the definitions in the development environment, and (at least) the landmarks in the bootloader, then the software can't know that there's more space available, and consequently, even if it would work, it wouldn't work any better.
Third point: It seems that the next release of the Development Environment, release 13, will support the new chip, with an appropriately tweaked bootloader. At that point, those of us that can change a socketed chip (if not much else) will be able to download the new software and swap-up the main chip to enjoy about twice the space for our programs to play in. But for now, its a little more complex than that.


Points one and two are correct.

For point three you need to get the bootloader on the ATmega328. I use the
ladyada USB-Tiny and a Makefile

It is not much work to get Arduino-0012 to use the ATmega328.

(* jcl *)


Well to put a clearer picture on it, the 328 has been avalible with a proper Arduino bootloader preinstalled and a patched Arduino Version 11 IDE avalible for downloading. I've been running the 328 for a couple of months now.




Jan 28, 2009, 03:59 am Last Edit: Jan 28, 2009, 04:01 am by westfw Reason: 1
Sparkfun and Adafruit are selling mega328s WITH a modified bootloader on them already.  The mega328s first appeared back in Early November, and promptly sold out, to become available AGAIN in January...

(actually, it looks like the Sparkfun 328 is "bare."  oops.)


I would buy some of these loose 328s, but I'm not much for early adoption.  Let someone else find the bootloader/ide bugs.  :)


What is required to make it work with a different clock?


Change AVR_FREQ in the bootloader Makefile.

(* jcl *)


So is there any side effect to trying to run the arduino with the 328 at 20Mhz?


Jan 30, 2009, 01:08 pm Last Edit: Jan 30, 2009, 01:08 pm by dcb Reason: 1
weird baud rates and timings await you.


weird baud rates and timings await you.

Theoretically a correct boards.txt entry will solve that, but I don't think anyone has tested it yet.

I'm tempted, just because I need to populate a new board but I'm out of 16MHz crystals, but happen to have a 20MHz on hand.



It appears to be $2.66 each when you buy 504 at Digikey.  

So...who's organizing the group buy?  ;D

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