A couple of recent product offerings, including the Sparkfun "Arduino Pro" and the Seeduino, use a soldered-on surface mount (SMT) AVR microcontroller rather than the socketed DIP used in the traditional Arduino.
On the one hand, an all-SMT design is cheaper to have manufactured, it frees up some room for possible additional features, and it make for a slimmer, perhaps sturdier, board.
On the other hand, you can no longer use the Arduino as a sort of programmer/development system for a bare microcontroller that would be moved into a final project with a different PCB and form factor, and the utility and cost savings of Arduino Kits is reduced.
I'm wondering how the community in general feels about the issue.
I generally use the Arduino as a prototyping platform, and use a custom board and another CPU when building the final product. I know lots of folks use the Arduino as-is in their projects, but that's not how I operate.
Having said that, I think the DIP versions are highly desirable for prototyping work so that the components can be moved around.
If the SMT versions result in significant cost savings or capabilities improvement, they win hands down. If capabilities and cost are similar, I prefer DIP.
I only have 2 Arduinos, and only got them a few months ago. I've already toasted the bootloader in one of them. It was easy to pull the chip and drop another one in and keep going. I guess it wouldn't be much more trouble to just re-burn the bootloader back on to the smt chip and then keep going, but you would have to buy a ICSP programmer instead of a few extra chips with pre-burned bootloaders.
I've also accidentally introduced 12V to the Arduino. I got lucky and didn't blow up the chip, but if I had I could again pull the chip and drop another one in and keep going. An Arduino with an smt chip would be toast at that point. Time to order a whole new board.
I like the option of the socket paradigm. With that in mind, my direction is to use the arduino to proto/test ideas, refine that, and then build a very bare bones system sans interfaces for programming, serial (as case may be), etc... use the arduino board to upload the code, and plug the chip into the extreme barebone board that does only what it needs to.
All that said, if an smt design was out and was cheap enough to invalidate the cost savings of doing it as described above, then I would be all for that.
I opt for the SMT versions myself. The Arduino Pro mini, for example, is small enough to fit in a breadboard. The beginners however may get more use from the through-hole versions. I say keep both
I'm not sure what to answer because of the subtitles to each choice.
I've moved the MCU into other projects and replaced it, and I've only once left a whole Arduino in a project (and that was because I wanted the USB interface and size wasn't an issue).
But on the other hand, I have no problem building and programming my own Arduino core on the target project and using the official board just for development, so a surface mount MCU is fine with me.
And to take it a step further, if they used higher end MCUs that are only available as surface mount, I'd love the chance to use the super-Arduino and I'd have no problem using the whole board in my final project if it were beyond the scope of a mega168/328/etc.
I prefer the DIP version for the ability to place it directly on a breadboard, the ease of soldering your own circuit on perf board or a custom board, the ability to program a chip and place it to a barebones setup, and for ease of replacing a blown chip, thankfully not something I've yet encountered.
My opinion is a DIP Arduino leaves those of us with less experience in soldering and microcontrollers more room to experiment and learn then a SMT product.
I'm not against a SMT Arduino, however I would always like to see a DIP version available first.
I say keep both
I should clarify that I'm not in any official position with any of the teams manufacturing Ardunino or freeduino boards; I'm just curious, and especially so as it might apply to future super-arduinos. I'm pretty sure that both versions will stick around for a long time. (Like the sites that sell both Arduino boards and Freeduino kits...)
I have been trying to make a Atmega168 MLF-32 to dip-28 converter board. I didn't have (and still not have) much time to test this, but someone else from the boards here tested them with mixed results.
If I recall correctly, the problem was that he could program the MLF-32 only once.
Here is a picture:
IMHO, the great thing about open source hardware is that -- people may choose whatever they like, or create one if no choice fits.
For replacing 555 timer circuits I use ATtiny13's. I program them with an ISP programmer. Complete system --- a 8 pin dip.
For devices that need communications (i.e. USB, RS232 or Ethernet) I would like a low cost building block.
If that building block is used in a controlled well designed environment and/or a finished product, SMT's reduce size and I beleive reduce cost.
Many of my projects in not so nice environments --- the replaceable part gets me going until I can figure out what I overstressed.
In another post, I have inquired about a standard socket to insert a non-smt Arduino for rough and tough experimentation and latter replace it with an SMT based ethernet web interface when I have to bugs out using the same interface socket.
In summary both designs are required.
I say keep the DIPs alive for a little longer at least. They are so useful for prototyping and mini-production. Deadbugging a smd CPU is just no fun, especially with a wirewrapper