Arduino Uno SMD

Massimo BanziJanuary 8th, 2011

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We’re releasing a new version of the Arduino Uno today, the Uno SMD.  This board is just like the current generation of Unos, but it features a surface-mounted version of the Atmega328 processor.   The design of this board was prompted by a shortage of the Atmega328 in the through-hole DIP format that we normally use.

We plan to continue production of the Arduino Uno with the through-hole version of the Atmega328 as soon as they are available again. In the meantime, we took this as an opportunity to add a feature to the Uno board that will please the more advanced users, by making it easier to re-program the 8U2 processor that handles the USB-to-serial conversion.

Atmel, like all electronics components manufacturers, is gradually phasing out through-hole parts because they are more expensive to manufacture, and because surface-mount parts are cheaper and easier to assemble using robotic assembly. It makes hobbyists’ lives more difficult, because these parts are harder to assemble by hand, but it is a reality we all have to face. Fortunately, community knowledge is helping hobbyists to keep pace with large-scale operations.  We recommend the many tutorials on surface-mount soldering like Sparkfun’s excellent ones here: For the beginner, we recomment Adafruit’s excellent soldering resources as well:  We hope to see a tutorial on surface mount soldering the Atmega328 SMD parts online soon too — if you beat us to it, please send us a link that we can share. As the availability of through-hole parts diminshes, we will need to work together as a hobbyist community to keep electronics fabrication knowledge growing.

As I said, we took the opportunity to tweak a couple of things on the board. We brought out 4 pins from the 8u2 onto a 2×2 connector that can be used to create a “bit-banging” ISP programmer like some people have done with the FTDI chip on previous models. We also made it very easy to safely upgrade the firmware on the 8u2.

Now you just need to briefly connect to ground the reset pin of the 8u2 for it to enter DFU bootloader mode. The using Atmel’s FLIP on Windows and Linux or dfu-programmer on Mac (and Linux) you can reprogram the firmware.

We hope this will help us deliver improved versions of the 8u2 firmware more easily but also encourage people to experiment with it more!






26 Responses to “Arduino Uno SMD”

  1. Tom Lynch Says:

    This is a great idea, however what ever happened to the Ethernet Arduino you guys were planning?

  2. funlw65 Says:

    “…was prompted by a shortage of the Atmega328 in the through-hole DIP format..
    … is gradually phasing out through-hole parts …”

    This is not happening with Microchip microcontrollers. For Arduino, I recommend you to use 18F26K22/18F46K22 microcontrollers. No need to scare hobbyists.


  3. funlw65 Says:

    I looked at your photo. Only that IC having 8pins (the larger one from the board) can be soldered by hobbyists, the other components (ATMEL) are impossible to solder by the majority of us, not matter how many tutorials you will post.

  4. reg Says:

    Wait, there’s a shortage of DIPs but plenty of TQFPs? I can get the 328 DIPs practically everywhere, TQFPs have been almost impossible to find for months (the 168s, thankfully, are still available).

  5. reg Says:

    funlw65: you’d be surprised how easy it is to solder tqfps with no special equipment.

    I’ve soldered 144pin tqfp ARMs with a fat-headed soldering iron with only a few bridges, which are very easy to fix. Just need to use a lot of flux.

  6. BIG NEWS – Arduino Uno SMD « adafruit industries blog Says:

    [...] BIG NEWS – Arduino Uno SMD. Massimo writes – We’re releasing a new version of the Arduino Uno today, the Uno SMD.  This board is just like the current generation of Unos, but it features a surface-mounted version of the Atmega328 processor.   The design of this board was prompted by a shortage of the Atmega328 in the through-hole DIP format that we normally use. [...]

  7. mitpatterson Says:

    Quick Question, when the DIP version goes back to production, will the changes(the 4 pins broke out of the 8u2 chip) stick? or is that exlcuive to the QFP version(since there is more board real estate?

  8. HoboDuino Says:

    I would have gone the quick and dirty way and created an SMD->ThruHole adapter which would fit on the existing arduinos and their thru-hole sockets. One thing I can see with this is that once the chip is fried you HAVE to get a new arduino, also, it is cheaper to get the SMD parts in quantities and MUCH cheaper to put on a board (robot vs. human) but I don’t know how much more cost effective it would be overall (for the manufacturers that is).

  9. liudr Says:

    I can imagine Dips going away but what about an adapter board that adapts an SMD to 0.1″ spacing headers on all four square edges. Then have some female headers on the main board. You can pull out the adapter board if the chip is fried and replace with another chip-on-adapter-board.

  10. Haitham Khedre Says:

    this design will fail , you guys should do adapter components that adapts an SMD to 0.1? spacing on Arduino board it self , or what is the purpose of getting soldered Arduino , you just release it fast , it is not hard do the adapter , this will fail for sure no one will buy some thing like this without the adapter component .

    review the design and at this happened start by doing adapter component that fit all Atmega chips for future use , this thing is too dangerous to the open source community and make it more close and hard to get.

    because you are Arduino Team , request from Atmel special treatment guys come on.

  11. funlw65 Says:

    Well, if is about adapters, then a boarduino like board is to be made. It will be even cheaper and you are already psychologically prepared to buy another one when yours will be fried.
    Otherwise, FreeJALduino can be a good example (and a solution).

  12. dossbrad Says:

    I am fairly ignorant about the intricacies of working with the Arduino board, having just purchased my first one last week.
    As a new user, I was excited about the ability to prototype and remove the chip from the board if I wanted to integrate it into my own circuit board.
    This new design seems intimidating now, even though I am getting a better understanding of the pins on the chip and how they integrate with the pins on the board. I’m not sure that I would have been as willing to even try working with microprocessors if I had to work with this new “less intuitive” design and the programing side as well.
    I hope that you continue to make the traditional board, because given the choice now, that is the one I would continue to purchase.

  13. Haitham Khedre Says:

    Lesson learned , try Arduino Team to take a survey before taking a step , and you will get many inputs that are really will help to reach the best design ,also try to think from now to Alternative designs , don’t depend on one source like Atmel , try to see other mcu that can give the same result , so Arduino is the concept that can work with many mcu , I know you are restricted by the board design , but why not taking over Atmel guys and PIC guys under one umbrella “Arduino” , with all this we are really open source and no one can restrict any thing.

  14. rebus Says:

    Arduino – SMD Components = Pinguino


    A great project to build your own boards !

  15. funlw65 Says:

    “because you are Arduino Team , request from Atmel special treatment guys come on”

    They did that first so, you can imagine the ATMEL answer. To be honest, I expected from Arduino team to take a wise decision before UNO. Now, they are trapped with the actual UNO…

    If they stick with ATMEL, then they will need DIP adapters but only if are not too tall.

    Otherwise, a change of mark will be very painful at the beginning but will gain more users – but the success will depend very much on the entire package offered (development chain). I think they will not dare to do this.


  16. funlw65 Says:

    Is very important for the development boards to continue to use DIP version of microcontrollers (and I’m not referring to demo boards), with a big cycle of reprogramming.

    EVB4.3 development boards are great for ATmega microcontrollers – will be too bad if ATMEL microcontrollers will not come anymore in DIP shape.

    But the good news about that board is the ability to work with any other external microcontroller (It is also proved on my site)!!! That I call an universal development board.

  17. rrc1962 Says:

    I just received on of these boards and there is a problem with it retaining the uploaded program after powering down.

    If I use the USB for power, when powered down then back up the unit goes into it’s bootloader flashing mode and the program does not run. Nothing I do recovers it to an operational state other than reloading the sketch.

    If I use external power (12V) it will retain the program sometimes but not all the time. When it does fail to boot properly, I can sometimes hold reset while powering up. This work sometimes, but not all the time. I wish I could be more specific, but there is no pattern here. Sometimes it works. Sometimes it doesn’t.

    There are others over on the SparkFun forum reporting the same problem.

    This board came with the inventors kit from SparkFun. I’m going to request they exchange it for the DIP style board. I’m using this board for prototyping. I plan on using the Pro 5V from SparkFun in the final project and hoping since it uses surface mount technology, it does not exhibit the same issue.

  18. thelaw Says:

    Keep the DIP package alive, we’re not robot. I think Arduino team kan negotiate with Atmel site to keep the DIP package available even with higher price due to production cost but that’s okay, many electronics hobbyst I think still prefer DIP package AVR for so many reason.

    BTW, if SMD package cheaper why Arduino SMD still have the same price with DIP version? CMIIW, yes because the component price might be cheaper but the labour cost maybe higher lol.

  19. smeezekitty Says:

    Please, If you use imposable surface mount, please use a socket.
    I spent THREE hours and suffered a panic attack replacing a FTDI chip on a duemilanove because the regulator shorted and applied 10v to the 5v line.
    If both chips are surface mount with twice as many pins, you are pretty much messed.

  20. Zinahe Says:

    I hate the look of the SMD board. It’s intimidating and unwelcoming to new comers. The DIY’ness appeal is just NOT there anymore. I hate to say this, but it was not a wise decision taken by the Arduino team. No matter what the justifications are !

  21. Matthias Says:

    SMD soldering isnt all that terrifying. I picked up the skill last year and havent looked back. As stated above, flux is key and so is a little patience but I don’t think it’s all that big of a deal. AVRs are incredible little processors and I don’t think the people here calling for a processor swap understand what that would result in in the interim. Now if you guys want to make one with an xmega… That’s something I could get behind. ;-)

  22. Rich Says:

    Like a previous poster….
    What happened to the ethernet enabled arduino board?
    Or how about a mega w/ethernet?
    The ability to flash the program via ethernet is needed by many.

  23. dave w Says:

    re: hand-soldering surface mount stuff: it’s not as hard as it looks… don’t
    try to do it pin-by-pin, just get it really well lined up and tacked down on 2
    sides, then get a bit of a blob of solder going on the end of your tip and run
    it along each row of terminals – think of it as “wave-soldering with a
    soldering iron”, and finish up with solder-wick to remove any excess, as if
    trying to unsolder the device (it won’t really, it actually leaves just enough!)

    I was skeptical myself, but I just tried it recently after someone told me it
    worked, and it was like an “aha! this is possible!” moment – at least with
    the .050in pitch “standard” SOIC’s. Next milestone will be the “fine pitch”
    stuff – the 0.5mm and 0.65mm pitch high-density pinouts.

    The really tiny leadless parts (with the pads on the underside of a little
    square ceramic brick) might be interesting: it might be necessary to leave
    a bit of an outward extension on the pad shape to enabling hand-soldering


  24. wayne mitzen Says:

    Be happy that Atmel didn’t kill everything but the 32UFBGA – a lot of companies are doing that.

    But honestly, my wife hates thru hole. We do one board for a lockmart thing that has 850 thruhole parts – she hates it. She’s done 0402 and TSSOP stuff with nothing more than a Hakko 936 and a Waveroom mag. I have a Mantis ’cause I suck. But I too prefer SMD…

    As to BGA’s, the one tech I work with makes it look easy. He prefers the cheap Chipmaster 2000 over the expensive Pace and similar for BGA rework. He used to fix cellphones; tiny little uBGA stuff with just a hand held hot air tool.

  25. Chuck Says:

    I was going to buy an Arduino but the news of not being able to take the chip out and put another in is a reason the board should cost less and a reason I might stay away from it. I shouldn’t have to buy a $30 dollar board to replace a chip.

  26. dave w Says:

    I just did an all-the-way fine-pitch part (0.5mm MSSOP-10 package) – an Analog Devices AD5304 quad D-A converter – with the same “blob-and-wick” method I described earlier – it works just as well as with the 0.05″ stuff.