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Topic: Better idea for SMT Uno (Read 2 times) previous topic - next topic


I think it'd be a better idea to put the SMT version of the AtMega328 onto a very small daughterboard, with two rows of pins on it, that can plug into the standard Arduino boards. This would allow people to replace the CPU on their Arduino's if it fails, or for any other reason want to change the CPU. It'd be like a breakout board for the CPU. This would have the benefit of there only being one version of the UNO board. It'd have the down side that the CPU's would cost a bit more to make, but with some volume, I bet it would be a negligible difference.
Just in case I'm not making any sense, here's an example (albeit in a larger package) of the MegaSquirt 2 CPU that replaced an earlier DIP package CPU.
Brian from Tacoma, WA
Arduino evangelist - since Dec, 2010.


but with some volume, I bet it would be a negligible difference.

Unfortunately, I don't think that there is any way that the cost of an entirely separate PCB plus 28 pins for the connector is ever going to be "negligible."   There are companies that do this sort of thing in order to provide "backward compatible" parts for chips that have gone "out of production" in their original form, and they manage to charge quite substantial amounts.
(There is also the problem that the chip in question here is quite narrow, and actually implementing such a PCB would be substantially difficult.)


Yeah, I figured the "adapter would have to be longer than the socket, so the CPU that's probably too wide to fit between the rows could be at the end of it (maybe underneath to keep the height down). Well, it was an idea..
Are you the guy from Systm? Or just have his picture as an avatar? I loved that show. :)
Brian from Tacoma, WA
Arduino evangelist - since Dec, 2010.


Jan 29, 2011, 02:37 am Last Edit: Jan 29, 2011, 02:47 am by CrossRoads Reason: 1
So you're really talking an adapter like this
but with a couple of pins left off to go from 32 to 28.
And narrower, maybe using the pinless package, the 32M1-A, the 328-MU and the 328P-MU, both 5mm wide, while the socket pins are ~8.2mm wide
(I don't see what the difference is between 328 & 328P in the datasheet, must be something subtle I am missing).
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

James C4S

How much are you willing to pay for this?  I have a set of boards coming back (hopefully this week) to test this idea.

What I suspect is that most people would rather wait a couple of months than pay 3x (PCB, connection hardware, and overhead) what the chip would have normally cost.
Capacitor Expert By Day, Enginerd by night.  ||  Personal Blog: www.baldengineer.com  || Electronics Tutorials for Beginners:  www.addohms.com

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