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Why the Raspberry Pi Won't Ship In Kit Form 240

Posted by Soulskill
from the you-are-too-clumsy dept.
An anonymous reader writes "A post at the Raspberry Pi blog shows an image containing the device's SoC and memory chip to help explain why the tiny PC won't ship in kit form. Clearly, the chips are so small, and the solder blobs required so tiny, that most people would mess up doing it by hand. Add to that the fact one chip has to sit on top of the other, and if you're a millimeter out, your chips are fried." The post also addresses the use of closed source libraries for graphics acceleration.
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Why the Raspberry Pi Won't Ship In Kit Form

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  • by Anonymous Coward on Tuesday January 31, 2012 @04:57PM (#38881783)

    How about we stop posting a Raspberry Pi story every goddamn blog post and save the talk for oh... I don't know... when the god damn thing actually ships?

    I've been throwing my money at the screen for months and NOTHING'S HAPPENING!!!

  • by Lashat (1041424) on Tuesday January 31, 2012 @04:58PM (#38881793)

    Should read EVERYONE without the nimble fingers of a child, the steady hand of a special forces sniper, and the sharpest soldering iron this side of the sun.

    • Don't forget (Score:3, Insightful)

      by nweaver (113078)

      Don't forget the reflow oven, so not only do you need superhuman skills, but you need a specialized tool that effectively nobody has.

      • Haven't people been reflowing PS3s and Xboxen in their kitchen ovens? Or does that only work for re-reflowing?

        • by sjames (1099)

          To some extent, that does only work for re-reflowing where the chip is already well placed and tinned. Even then, you are likely to shorten the life of the components somewhat since you won't have good enough temperature control.

          Reflow soldering involves heating the components much hotter than they like to be even when powered off. The heating and cooling times are carefully controlled to keep the stress of that to a minimum while still making reliable connections (usually).

      • Re:Don't forget (Score:5, Interesting)

        by Achra (846023) on Tuesday January 31, 2012 @05:13PM (#38881971) Journal
        People have been doing BGA in toaster ovens for a while now. I'm not saying I'd try it with stuff this size, but it is doable. http://www.die4laser.com/toaster/index.html [die4laser.com]
        • by Microlith (54737)

          But have people been doing package-on-package BGA assembly?

          Seriously, I think that's one huge thing people are missing. This isn't one chip package on the board, it's two stacked.

        • Re:Don't forget (Score:4, Informative)

          by smellsofbikes (890263) on Tuesday January 31, 2012 @07:13PM (#38883659) Journal

          I put BGA's, LLP's, and SON's on boards by hand all the time. I use a hotplate that goes to 260C rather than a toaster oven because I can place it and then look at the edge with a boom-type microscope set at 45 degrees. With a BGA you can see slightly under the package to make sure the balls are on the pads; with an LLP or SON you can see the edges of the chip leads and make sure they're aligned with the pads. Check all four sides, because it's not uncommon to have one side lovely, the two adjacent sides slightly twisted, and the opposite side almost one whole pad off. If you're using leaded solder it'll tend to self-align, but you can't trust that. Bolting insulative material (we used old FR4 boards) to each side of the hotplate prevents you burning your hand from touching it by mistake and provides you a place to steady your hand while adjusting the rotation/placement with a dental pick. We place 0.5mm pitch BGA's (which we call microSMD's) this way on a regular basis, when our BGA rework station is busy or down.
          AND! it is possible, although painful, to check continuity to the chip from the board, in many cases, without an x-ray. Check for a diode drop from each node to the substrate.

      • by petscii (318753)

        SMD is actually easier than through hole in my opinion if you factor in the time/cost to to drill 400 holes(called vias) in a through hole pcb and the lack of easy plating of vias at home. Also a lot of components are just not available as anything but SMD.

        http://hackaday.com/2012/01/01/a-very-detailed-reflow-oven-build/

        That reflow oven works, and was built by a lowly technical college dropout (myself) with great success. You just need to get the data sheet for your solder and set up the various temperatu

    • by Synerg1y (2169962)

      You can always do stuff to steady your hand temporarily, but I'm not sure where the discussion is: who would want to? Even if you can, the price point might be lower than your hourly wage so why bother. There's plenty of other stuff to solder, like your friend's gaming console :)

  • by vlm (69642) on Tuesday January 31, 2012 @05:02PM (#38881829)

    BGA packages are intimidating, even to a guy who's been hand soldering other SMD packages since around/before 1990 (that being me)

    Plain SMD is easy to do by hand, even the 0402 stuff.

    The thing with BGA is its an alignment problem. Some entrepreneur will likely invent a magic clamp that holds the chip in perfect registration to the PCB, at which point it'll be dirt simple to solder BGAs.

    I donno where the "if you're a millimeter out, your chips are fried" stuff comes from because thats /.ed. I've done analog microwave RF work where that is actually true. That is not possible on a logic level board. "oh noes, /ce has been grounded, whatever shall we do?" Well just fix the solder bridge and stop whining. Its not like you just shorted out a 20 amp 24 volt power supply thru the bias/bypass network of a microwave FET amplifier, nothings going to blow up on a digital ckt.

    • by SomePgmr (2021234)
      I have a hard time with the smd stuff. Probably not enough practice, but even with reasonably steady hands and a magnifying lamp on my workbench, I tend to screw things up. And these things are so cheap to begin with, I'd have bought the assembled model anyways.
    • by allanw (842185) on Tuesday January 31, 2012 @05:11PM (#38881951)

      I don't understand why people even want a kit at all. The assembled version is already ridiculously cheap due to high volume. There's tons of surface mount parts that would be annoying to even package for people. Why ruin a perfectly good small form factor to make it a little easier for a few people who want to solder it themselves? Also, it would take you hours of your own time assembling it. Why don't people design their own hardware instead?

      The much bigger problem is the lack of documentation on accessing the GPU (which is a more modern design and pretty powerful compared to the older ARM CPU core they're using)

      Another issue is that it is very hard to debug an assembled board. If one of the pads on the BGA doesn't make contact it's nearly impossible to diagnose. A power to ground short would be very difficult to locate. They can't use their automated test jig to sort out defective parts or errors in assembly, etc. And then the manufacturer will be prompting tons of support requests by people. It really isn't worth the effort.

      • by TheGratefulNet (143330) on Tuesday January 31, 2012 @05:51PM (#38882507)

        I want one assembled AND TESTED.

        I'll pay for that.

        debugging a software bug (my own code, say) is hard enough without second guessing the hardware.

        csb: a friend of mine is trying to convince me to use an arduino mega (high density smd-only chip) where I'm currently using the skinnydip28 version of the regular 328-style arduino (which is .1" thruhole and easy to deal with). at the very least, if I was moving to a mega (25xx class), I'd insist on it being on a carrier board AND that board being built to high spec and the cpu tested on the board before being delivered to me for assembly into a larger system. I refuse to have to worry about the cpu AND the rest of the system (being a small company). I cannot find good mega-class chips already on carriers (.1-friendly carriers) AND tested AND by a company I'd trust to actually care about quality. being able to buy it pre-tested is key, to me.

        back to r-pi: I'd want this to be known and tested as a FRU of its own. the thing is small enough to be its own field-replaceable-unit in a larger embedded system; and if any part on it is bad, the whole thing gets replaced.

        • by vlm (69642)

          csb: a friend of mine is trying to convince me to use an arduino mega (high density smd-only chip) where I'm currently using the skinnydip28 version of the regular 328-style arduino (which is .1" thruhole and easy to deal with). at the very least, if I was moving to a mega (25xx class), I'd insist on it being on a carrier board AND that board being built to high spec and the cpu tested on the board before being delivered to me for assembly into a larger system. I refuse to have to worry about the cpu AND the rest of the system (being a small company). I cannot find good mega-class chips already on carriers (.1-friendly carriers) AND tested AND by a company I'd trust to actually care about quality. being able to buy it pre-tested is key, to me.

          I haven't worked w/ that hardware, but can't you do your software work on some dev board, even if you have to really hack the heck out of the dev board with wires laying everywhere? I've certainly done stomach turning things to poor defenseless dev boards in the past. I agree doing hardware and software dev at the same time is ... overly exciting.

          I donno if you like or hate seeeed studios or whatever but slapping together a simple single chip carrier PCB and having them solder just one chip to one simple

        • by allanw (842185)
          Of course, you're buying a final product from the Raspberry Pi guys. It's understood to be assembled and fully tested. I was talking about a "kit" version where they sell you the PCB's and let you assemble it and test yourself.
      • by vlm (69642) on Tuesday January 31, 2012 @05:57PM (#38882581)

        I don't understand why people even want a raspberry pi at all. The apps on the itunes app store are cheap. Why ruin CS and IT to make it a little easier for people who want to write their own programs? Also it would take you hours of your own time to write and compile your own software.

        Come on man, its a hobby. When a dude puts together a 1000 piece puzzle you don't pee all over it by claiming you can buy a poster of the same picture and thats a better choice because you don't have to put it together... That kind of misses the point.

        The fun fun fun of kit assembly isn't in working a 16 hour shift assembling it with chinese music on pandora, eating a couple rice grains and some tea while wearing a political prisoner uniform, and pretending your boss beats you for not working hard enough. Unless you like that kind of stuff. Whatever floats your boat. Anyway the fun of kit building is kit bashing weird stuff from different eras to massively customize the project to what you want. Something I've been up to on the bench recently: I started with a fairly modern microwave local oscillator kit. Then I swapped out the crystal because I need to work on a different frequency for a completely different ham radio frequency band. Then I smooshed in a completely different voltage regulator circuit; ugly as heck but I don't care; I want/need to run off 24 volts instead of 12 volts (long story there). Didn't want to buy a modern MMIC amp for the board because I had some old 80s era tech mmics laying around so I redesigned the bias ckt for the correct voltage drop and forward current (exactly as complicated as lighting a LED, just stuck a different value resistor in; didn't wanna build a constant current supply, at least not this time). So far so good. Also added a stylish power LED so I can tell my regulator hasn't shut down from overheating..... yet.

        I think it would be fun to completely redo the I/O on a raspberry pi, at least to begin with that is the most obvious thing to do. Also some stuff I simply don't care about, I would not solder on. Not gonna do the composite video thing, not gonna waste time soldering it on. Probably would rip out the audio stuff figure out how to directly wire a software defined radio directly to the board. If the first thing in the TX chain on the SDR is a giant attenuator, and the last thing on the Pi audio out is a high powered headphone amp, simplicate it and toss both replacing both ckt sections with a piece of wire. etc.

        • by gknoy (899301)

          Giving your kid a Raspberry Pi, letting him hook in a keyboard and plug it all into the TV, and then get started programming makes it seem pretty compelling. Of course you might not be building large apps and games, but come on -- nearly every toy or educational program one might write will run just fine in an interpreted environment, and would likely compile very quickly.

          Being able to run XBMC and hardware accelerated 3d graphics are neat, too, of course.

        • by dissy (172727) on Tuesday January 31, 2012 @07:30PM (#38883863)

          Come on man, its a hobby. When a dude puts together a 1000 piece puzzle you don't pee all over it by claiming you can buy a poster of the same picture and thats a better choice because you don't have to put it together... That kind of misses the point.

          You do have to admit that there would be a ton of people purchasing the kit for no other reason than to save $3, and then break it and attempt to return it for a refund or hound their support email.

          Perhaps if it was legal to sell kits specifically with NO warentee at all and a no return policy, then it may work... But in many countries that isn't even an option.

          To take your puzzle example, yes people who do puzzles as a hobby are fine, just as people who actually like to assemble circuits like this would be fine.
          But the people trying to do nothing but save a buck are the exact type who would purchase a puzzle, put most of it together, then bitch that it doesn't at all look like the poster due to the wavy lines between the pieces, and return it demanding more than a full refund at the puzzle makers expense.

          I would like to believe after the first few production runs of fully built units, that later on they would put some effort into selling the specialty parts (PCB, pre-flashed chips or roms, harder to source components like odd freq crystals, etc) and put up the parts for sale individually along with the BOM and schematics.
          That's the only way around the warentee problem with kits, and the only way to make it too much trouble for the people trying to only save three fifty. For electronic hobbyists, working from a BOM and schematic is business as usual, and not really any extra work we weren't expecting anyway.

          Then everyone is happy!

    • nothings going to blow up on a digital ckt.

      What if the chips have different I/O and core voltages? This is true for many processors and FPGA's that come in BGA form. I'd bet the ball pitch is .5 or .4mm so if you're off by a mm you could easily connect 3.3V to the 1.2V core. That would indeed fry the chip. Or 3.3V could go straight to ground which could fry the actual PCB since the traces are 5 mils or less and can't handle 500mA for long. Also, that "magic clamp" exists as a $60k CNC heat column in my lab at work. Once you program the reflow profil

  • whatever... (Score:5, Insightful)

    by spidercoz (947220) on Tuesday January 31, 2012 @05:02PM (#38881839) Journal
    I still want 10 of them...
  • by Chemisor (97276) on Tuesday January 31, 2012 @05:13PM (#38881981)

    And to think that only 30 years ago a resourceful fellow could fix a circuit board with a silver dollar, pliers, and a car battery. With today's electronics, MacGyver would be dead.

    • And to think that only 30 years ago a resourceful fellow could fix a circuit board with a silver dollar, pliers, and a car battery. With today's electronics, MacGyver would be dead.

      Fortunately Ben Browder would still be available to play his replacement.

    • serious answer: you 'fix' this by having shelf spares.

      when one breaks, you replace it. maybe send the bad guy back but definitely swap it and you need to have spares on the shelf.

    • by gman003 (1693318) on Tuesday January 31, 2012 @05:56PM (#38882567)

      With today's electronics, MacGyver would just do it all in software.

      • by Chemisor (97276)

        Speaking of which, have you SEEN today's software? Hordes of programmers work on it around the clock and still can't fix it.

    • Not if he had Jack Bauer's writers:

      Terrorist: Fred, Rewire the CI-Plot Device to blow up the eastern sea board or I'll tell Suzie you cheated on her!

      ...6 min later...

      Fred: Jack! the terrorist just escaped via submarine helicopter!

      Jack: Chloe, patch me through to the Deap Sea satellite imaging array!

  • Import/Export Tax (Score:3, Informative)

    by Anonymous Coward on Tuesday January 31, 2012 @05:21PM (#38882063)

    I thought the main reason they couldn't build the Raspberry Pi in the UK was there were prohibitive costs to importing the needed components whereas the completed device was taxed differently.

    Isn't this the same problem?

  • by Animats (122034) on Tuesday January 31, 2012 @05:22PM (#38882079) Homepage

    The stories about this board need to stop, at least until they ship the thing. "We bought the parts". "We soldered them on", etc. do not each need a separate story.

    Of course you don't ship kits of SMD parts, especially ball-grid array parts. Such a soldering job is cheap in a production environment, and a huge pain even with the right equipment in a small shop. (It's done in production by printing a solder paste layer on the board with a mask, and the final alignment of the pads is done by surface tension in the molten solder. It's all about temperature control and solder paste depositing. Once the production line is tuned right, it works quite consistently.)

  • The fact that they won't deliver in kit isn't news*, it's more interesting to know that they have HW-accelerated versions of MPEG4 and H.264 (and only those), and that all these libraries are closed source.

    Furthermore, claims that they have the fastest mobile GPU are fluff: we only have the subjective word of someone who worked on it, not a neutral 3rd party, and it'll be caught up by someone else soon anyhow.

    Finally, I'm going to advance that any complaints about the nvidia binary driver are going to be small fry compared to Broadcom's drivers.

    *it's just not possible to hand-solder BGA packages. At best you'd need a reflow oven, and *that's* still tricky with the sizes involved here.

    • by Creepy (93888)

      I suspect contractual obligations to Broadcom require them for building in hardware acceleration, as in perhaps they get a discount rate on licensing the codecs if they require them. Tegra 3 (Kal El) has built in hardware acceleration for them and I think Snapdragon 4 as well.

      Definitely not the fastest GPU, and certainly not the fastest SoC, but I don't know about when they started cobbling it together, or if they were trying to say fastest they could get at the price point they wanted to meet.

      Reflow ovens.

    • by boley1 (2001576)

      The fact that they won't deliver in kit isn't news*, it's more interesting to know that they have HW-accelerated versions of MPEG4 and H.264 (and only those), and that all these libraries are closed source.

      HW-accelerated versions of MPEG4 and H.264 isn't news either except its on a board that cost $25!
      (and only those), well the last time I licensed MPEG2 it cost me $14.95, so getting a complete board and a codec that is hardware accelerated and including the license fee for $25 - I agree, that interesting and news.

      That all the libraries are closed source - Not news since practically all commercial grade GPU libraries are closed, but since the API is public and directly mapped to the normal Linux Graphics Lib

  • by JDG1980 (2438906) on Tuesday January 31, 2012 @05:33PM (#38882245)

    This article also confirms that the Raspberry Pi will likely be worthless as a media streaming device - at least for those of us who care about video quality.

    It is now official that only H.264 (and MPEG-4) will be supported for hardware decoding. That means that playback of ripped Blu-rays that use VC-1 and MPEG-2 (not an inconsiderable number) is impossible, since the weak ARM CPU will almost certainly not be able to decode them in real-time at 1080p.

    I'm sure the Pi will work fine for people who play back transcoded crap downloaded from TPB, but for anyone who actually cares about video quality, the lack of these essential codecs is a death sentence. We can only hope that at some point in the future a different (even if more expensive) model will ship with them enabled.

    It's really a shame that there is currently no open-source-friendly SoC platform that supports HD video decoding and HDMI 1.3 audio bitstreaming in all its forms. HTPCs mess with the signal in all kinds of ways (YUV->RGB conversion is forced, even if you select YUV, it converts to RGB then converts back) so SoCs are really all that can provide decent quality. And the firmware on commercial media streamers is almost all crap.

  • by AdamHaun (43173) on Tuesday January 31, 2012 @05:49PM (#38882485) Journal

    http://www.raspberrypi.org/archives/592#comment-10077 [raspberrypi.org]

    liz on January 31, 2012 at 9:17 pm said:
    Indeed – we have to use an x-ray machine with microscopy to ensure all the pads are connected properly. And NOBODY has one of those at home.

    This post has just been Slashdotted. http://hardware.slashdot.org/story/12/01/31/203229/why-the-raspberry-pi-wont-ship-in-kit-form [slashdot.org] Plenty of commenters there appear downright insulted that we don’t think they’ve got ovens, masks, and an x-ray machine at home, along with the dexterity of a TINY TINY PIXIE. (They don’t have any of those things, but they’re still insulted.) Sometimes I really hate Slashdot.

    • Well played.
    • by 15Bit (940730)
      If by "x-ray machine with microscopy" they mean an electron microscope with x-ray analysis system (EDS), i do actually know someone who has such a setup at home. He is a bit geeky though...
    • by Hatta (162192)

      Those people were never going to be customers in the first place. The binary blob is a real problem for a lot of actual customers though. I have a fully open source HTPC already, I was hoping for something smaller, quieter, and less endergonic. If I have to sacrifice open source for it, that might be a deal breaker.

    • by Svartalf (2997) on Tuesday January 31, 2012 @06:32PM (#38883095) Homepage

      I can't say I blame Liz on that score.

      She's right- unless you're REALLY good, you're going to need all of the things she's talking to- and MOST of us over here won't have them.

      I view the only shame being that the state engines are going to be closed source blobs. It seems that NOBODY out there in the embedded/mobile space has the forethought to open things up a bit. First one to open up an ES/VG/etc stack on their GPU will gain a lot of design wins, based on what my clients in the past have indicated.

  • But. But.

    I AM a pick and place robot, you insensitive clod!

  • Stop whining (Score:5, Interesting)

    by Required Snark (1702878) on Tuesday January 31, 2012 @06:46PM (#38883297)
    If you don't care about the Raspberry PI, don't read the article or post about it.

    If you think it gets too much attention on Slashdot, don't read the article or post about it.

    If you think it should be a kit, design a similar system and only sell it as a kit. The people behind the R. PI didn't just sit around and whine, they did something. Don't just complain about it.

    If don't like the closed source drivers, then reverse engineer them yourself. Or get together with the people who want an kit and write their software. Do something beside bitching.

    If you think that assembling a kit at this scale is easy, set up a web site that shows how it can be done. Sell a kit of supplies for the process. Don't just emit hot air.

    You people act as if the motto of Slashdot was News for crybabies, Stuff that sucks

  • by sunderland56 (621843) on Tuesday January 31, 2012 @08:27PM (#38884601)
    Seriously - what computer does come as a component-level kit? Yes, the Altair did, but that was a long time ago. Does anyone really sell a bare motherboard??
  • by Prune (557140) on Wednesday February 01, 2012 @02:00AM (#38887743)
    Considering you can buy a hot air soldering system for little over $100 on eBay, I call BS.
  • by pbjones (315127) on Wednesday February 01, 2012 @02:27AM (#38887917)

    with the automated assembly vs kit form, I would guess that a kit would be 3 x more, because of all of the manual handling required to get kits together. Electronics like this has really moved on from kits.

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