Parallella $99 board now open hardware on Github

Michael Kellett wrote:

 

I have a plan to attempt BGA soldering with less than £100 worth of gear but I'm not going to try a £200 chip to start with.  Cheaper suggestions in 1mm pitch are welcome.

 

MK

Xilinx Spartan-3A in FT(G)256 1mm 16x16 BGA.  One nice thing about FPGA is that you can use JTAG boundary scan to verify connectivity for testing your process.

selsinork wrote:

 

However, the downside for OSHW is that if you're not prepared to deal with parts that have the density seen in commercial designs then you're likely to be artifically limiting your creativity, especially as newer parts start to become available only in BGA.  Of course the other side is that you may be limited anyway by not being able to afford to get a BGA design produced for you by a commercial outfit when you're only talking tiny numbers.

 

Does the net effect mean that OSHW becomes self limiting simply due to needing to take the step into commercial production, but not wanting to do that ?

I think it means that you're limited to what you can get in the form of a plug-in module, something Morgaine talked about recently.  If the interest in FPGAs becomes solid enough, it's easy enough for SparkFun and/or AdaFruit to make modules for them, particularly since a single PCB can usually handle several pin-compatible devices.  But the volume has to be there.

John Beetem wrote:

 

I think it means that you're limited to what you can get in the form of a plug-in module, something Morgaine talked about recently.  If the interest in FPGAs becomes solid enough, it's easy enough for SparkFun and/or AdaFruit to make modules for them, particularly since a single PCB can usually handle several pin-compatible devices.  But the volume has to be there.

OSHW-friendly companies like Sparkfun and Adafruit can help us out by making breakout boards for tiny SMD packages that many OSHW people find difficult to handle, and that includes pre-mounting BGAs.  To me that suggests that even if there will be no home-solderable devices in the future, it won't mean the end of home construction.  I don't see a future of doom and gloom in that area --- quite the opposite in fact, as the maker and OSHW scene is blooming, and  small companies like the above are often happy to exploit small niches of demand.  I'm sure that many others will join them.

On the separate issue of equipment form-factors, although commercial manufacturing and marketing seems obsessed with miniaturizing everything, OSHW communities don't necessarily have the same needs and can be resistent to the marketing message that "tiny == cool" when they also know that "tiny == unmaintainable".

As environmental awareness rises, unmaintainable devices are seen more and more as products of an extremely blind waste economy, an inherently destructive aspect of current-day electronics and extremely dangerous to our own future.  There's a perfect storm gathering in power as waste tips turn into mountains and leeching toxins pollute our water supplies, and unless we do something about the forces that are feeding it, there are bad times ahead for the world.  It goes far beyond OSHW's normal interests, but perhaps it's time to change that.  Creating modular and highly maintainable computers would be a small step in the right direction.

Certainly there is some scope for break out boards but they don't really answer for the high performance chips. FPGAs with 484 or more pins are common and the bigger processors have far more pins than that. A breakout board ends up with an awful lot of pins but with high speed signals you can't use simple 0.1" or 2 mm headers but you have to use expensive impedance controlled connectors.

The only way round this is to put more on the board so it morphs from breakout board to SBC with pcie/ethernet/usb but of course that is exactly what we don't want.

My way forward on this is to try and assemble more exciting parts using simple "kitchen" type technology.

MK

Michael Kellett wrote:

 

My way forward on this is to try and assemble more exciting parts using simple "kitchen" type technology.

I agree, and I'd also like to add another small point about effective engineering to reduce the dependency on complex top-end devices.

Systems almost never have an equally high-speed requirement in all their parts.  In the huge majority of cases, only a few small sections have a need for an FPGA's top speed, and the rest of a solution performs more leisurely duties.  What this means is that if you slap a microcontroller alongside an FPGA, in most cases you'll get exactly the same level of performance determined by the high-speed logic, yet you'll be able to use a much smaller FPGA because the slower parts of the solution are handled in software.  That's much more effective engineering.

And once you observe that more effective engineering means splitting off designs into sections, only a few of which need to be high-speed, then you can get away from the high-cost parts containing a billion gates and needing out-of-reach assembly techniques.  "Kitchen" type technology then becomes adequately effective.  OSHW doesn't need ultra-dense devices with all the problems they introduce.  They're a poor fit for us.

Some big troubles at Adapteva have delayed Parallella --- latest Kickstarter update #41.

Check out my Adapteva delivery

http://www.element14.com/community/people/Problemchild/blog/2014/05/21/parallella-from-adapteva-arrives-at-last

I was reading about it finally shipping the other day.. So the question... was it worth the wait ?

Don't know didn't arrive with much fanfare  I think they had so much trouble with it that as soon as it was functional enough to be retailed then straight out the door it went