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[on:]

I found a guy on Amazon selling replacement pre-programmed "Duemilanove only" chips pretty cheap. The part number seems to be the same as the one in my Uno. Would that chip work unmodified in the Uno, or would it have to be reprogrammed in order to work?

If they'll work "out of the box" I might pick up a few so I could migrate projects off the board easily.

[Reply #1 on:]

Personally I would question why someone would program a chip with a few years old bootloader before clicking "BUY!!1!1!1!1".

But that's just me.

The "board type" is more of what bootloader is programmed than the actual board.

Good luck with whatever you are buying.

[Reply #2 on:]

Ok looks like I may have found the right search query to find a similar topic:

http://arduino.cc/forum/index.php/topic,139160.0.html

Looks like the answer is, yes, but you must select Duemilanove when you use a chip programmed originally for the Duemilanove.

Maybe if I pick them up, I'll put a D on them with a marker so I remember to upload programs in Duemilanove mode.

EDIT: This was posted before I saw the response above.

[Reply #3 on:]

They were going for a dollar each which was the cheapest I could find a 328p-pu on amazon.  I have a 30$ gift card I got for Christmas for Amazon so I was planning on buying some Arduino stuff.  Right now I just have the newsite uno r3 kit with the breadboard and wires but no components.  I was considering the green box kit that's on amazon for $22.50 but it already has the breadboard and wires which I already have.

[Reply #4 on:]

The old adage "if it is so cheap I can't believe it, it must be true!1!" applies in most cases.

[Reply #5 on:]

There are bargains to be found from time to time, in spite of James pessimism, but this one appears to not be one as if it's the same listing I found on Amazon for a $1 328p, has a rather interesting shipping charge:

http://www.amazon.com/ATMEGA328P-PU-with-Arduino-Bootloader-Duemilanove/dp/B00761CCH0/ref=sr_1_31?ie=UTF8&qid=1356650135&sr=8-31&keywords=atmel

$1.00
+ $4.99shipping

Lefty

[Reply #6 on:]

Yeah I think I found a better deal.

http://www.amazon.com/gp/offer-listing/B007SH0D0A/ref=dp_olp_new?ie=UTF8&condition=new

2.95 + 1.95 shipping.

[Reply #7 on:]

If it's a genuine chip you can put the Uno bootloader on it easily enough.

[Reply #8 on:]

If it's a genuine chip you can put the Uno bootloader on it easily enough.

There are fake atmegas?

[Reply #9 on:]

...  pre-programmed "Duemilanove only" chips  ...

What sort of chip can only be a Duemilanove? Not a genuine one.

[Reply #10 on:]

If it's a genuine chip you can put the Uno bootloader on it easily enough.

There are fake atmegas?

Yea, they are called PICs. 

[Reply #11 on:]

...  pre-programmed "Duemilanove only" chips  ...

What sort of chip can only be a Duemilanove? Not a genuine one.

I think they said that because they put the Duemilanove boot loader on it. I don't believe it is fake.

[Reply #12 on:]

There are fake atmegas?

Yup, as Sparkfun found out in 2010 . It makes for some interesting reading.

http://www.sparkfun.com/news/350
http://www.sparkfun.com/news/364
http://www.sparkfun.com/news/384
http://www.sparkfun.com/news/395

[Reply #13 on:]

There are fake atmegas?

All components are victims of counterfieting and shipping known bad parts.  Even capacitors...

Buying from well known supply chains significantly reduces this chance from happening

[Reply #14 on:]

I see, but looking at the evidence it seems they can't yet clone a fully working atmega328 for example cheaper than the original one.