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Raspberry Pi PCB Layout Revealed
An anonymous reader writes "Yesterday, the final Raspberry Pi printed circuit board (PCB) layout was revealed. The word 'packed' comes to mind as this is one very complicated looking board. The reason for that is just how much Raspberry Pi has strived to save money on the machine by using complex routing to keep things small and cheap. The Raspberry Pi team don't believe the design is going to change again unless they missed something. With that in mind, they revealed the final board is exactly the same size as a credit card, measuring 85.65 x 53.98mm."
How am I going to use this computer without a screen and keyboard?
I demand a credit card sized keyboard and screen!
Huh? What's complicated about that board? Looks pretty normal.
ARM11, specifically ARM1176JZF-S 700-megahertz which is a component of the Broadcom BCM2835 SoC.
While it's cool that they got the cost so low I'm kind of sad to see all those SMC's, kids today can't get into building electronics because so much stuff has gone to stuff that you just can't solder by hand. Yes, I know you can still use microcontrollers with breadboards, which is cool if you want to make a simple robot, but stuff like building your own computer that you can hook up to your TV and use like any other computer would be very cool as well.
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
RTFA: BCM2835
At first glance, this looks like a normal routing with a 4-layer board. Eventually 6, if you add proper ground + power.
There's nothing indicative of PCB parameters, like drill sizes, clearances, blind/buried vias, minimum trace width, so on. Again, a simple look reveals nothing but common parameters for PCB.
Again, TFA is biased.
Penguins and Altoids tins happen to be about that size as well... I wonder how well a populated Pi will fit... if so, awesome little PC cases!
I'm fine with this. R-Pi is worth it.
This could make a pretty big change for computing hardware and software learning.
Too much is done on overbloated hardware where you aren't even exposed to said hardware.
Most people in computing don't even understand the very basics of yester-2-decades-agos knowledge.
The most they touch on it sometimes is throwing together things in Java, if they are lucky.
It's all fine and well if you can do X on a really powerful computer, but being forced to do it and have noticeable slowdown or inefficiency in code by not doing it is a HUGE difference.
Having limits forced on to you in order to design efficient code is the best way to design said code.
But most developers these days are absolutely atrocious at their work, abusing the hell out of hard drives, flooding your RAM and page files with crap all over the place because they feel that their program has more worth than another persons program.
Worse when they do all that AND LAG LIKE HELL. (STEAM! DAMN IT VALVE FIX THAT CRAP ALREADY)
PEOPLE. MULTITASK.
I'm hopeful for the next generation of developers actually having an education on this, as well as possibly other similar boards. (admittedly a little on the expensive side in comparison)
So many lost techniques with all this high-level abstracted knowledge.
It's like building the frame of a car without the body. Sure, people could push it, people could pull it, hell, they could roll it down a hill. Still doesn't work efficiently.
Really, it's not. I do stuff like this every day. It looks pretty normal for a 4-6 layer board with a BGA or two on it. TFA needs to learn about what modern design standards are. It's only complicated if you still lay boards out with ruby tape or a sharpie.
This is not a sig. this is a duck. quack.
1080p30 using h.264 is the top specification.
They demoed it running 1080p video smoothly at a tech show. I don't remember the specs, but, for the price and size, I remember being impressed.
1 (short ton / firkin) = 89.1432354 slugs / keg
While I'm with you on this on many levels (remember building things with the 4000 series? Yeah, we don't do that anymore. Haven't since PICs. We just write some code that does the job much better), I wouldn't say that kids can't get into it anymore.
SparkFun, for example, regularly organizes PTH and SMD soldering classes as well as offering kits for both. Some SMD you can solder by hand quite easily, others you can get a nifty breakout board that lets you easily seat the SMD IC and melt solder up to its leads ( http://www.youtube.com/watch?v=-32orELxkpE ), and yet others you get some solder paste, a syringe or a toothpick (seems popular), put the paste on the pads or dip the leads in the paste, put the part on the PCB, and then stick it all into your toaster oven.. or on a skillet.
Of course for most kids, just playing with e.g. Arduino and some shields/sensors is going to be a great way to get into electronics in the first place.. then when they need something that's not on the market they can explore PCB design, soldering, etc.
Why not? The CMOS 4000 series and TTL 74xx series is still around, even in the various combinations (74HCxx CMOS, 74HS, etc). They're still availble from Digikey and the like, and many designs actually use them still.
If I could ever easily design a non-expensive Sci-Fi armor suit that has redundant, networked computers, streaming video-to-internet from a helmet, real-time video display in helmet, easily detachable web cam/mic/speaker modules that can be used on or off armor, and able to be worn from -50C to +50C I would build it for my Halloween costume and stream visiting Halloween parties to a web page. Reusable for comic and anime cons too. Heh.
Slashdot has become an RSS feed for the Raspberry Pi blog
Yes, how dare a site that claims to be 'news of nerds' cover a project to build a cheap computer designed to be interesting for school-aged nerds to play with? I demand more Apple stories, and political news!
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...and yet, just like the OpenMoko FreeRunner (giant opaque SMedia Glamo blob meant 2d VESA grade graphics only) and the OLPC XO-1 (giant opaque Marvell blob meant the whole WiFi subsystem and "mesh-while asleep" was all a black box and driver couldn't be troubleshot) , all the software is "open" yet obfuscated
The entire Raspberry Pi depends on a gigantic proprietary blob from Broadcom.
Hmm. Google search came up with this deviantart for "Raspberry Blob", maybe this can be the project's mascot. Hooray for undocumented blobs, we don't need source code, maybe we'll get Windows CE for it someday!
o/~ Join us now and share the software
a perfectly cromulent word
That's what Arduino shields are for.
It would be rather difficult to make any GHz computer board these days using parts that a person could solder by hand. That's the price we pay for having $100 GHz computers.
The determined Real Programmer can write Fortran programs in any language.
Thereby improving the quality of Slashdot. It at least guarantees an occasional techie story.
The real question is whether the underlying APIs will be open to the public, or if you'll have to sign some sort of Broadcom NDA to actually use the features the hardware already contains. Also, I'm interested to know if HDMI 1.3 bitstreaming (TrueHD and DTS-HD) is incorporated. These shouldn't require any licenses since the data isn't being decoded, just packetized and sent over a cable.
*If* the APIs are open, this could be a great XBMC platform with full support for all the Blu-ray codecs.
XBMC is working on a port. That could make a big difference.
I personally would like emulators.
Well, it can run Linux, so I suppose you could use it as an ultra-cheap nettop for someone who just does web browsing and email.
It could make a good XBMC platform assuming they open up the APIs for HD video stream decoding.
It could also be useful for embedded system applications for which an Arduino or similar device is not powerful enough.
Y'know...being candid, I'm barely interested in Raspberry Pi at all...but this is definitely of note for the target audience for Slashdot, or what Slashdot used to be in the late 90s when I first started reading it. Much better than some of the really worthless ask slashdot questions that get through, for instance.
I'm getting to be on the fence about this - maybe one Raspberry Pi story a week would be enough (same for any other nerd-worthy topics), what's the point of editors if they just re-post everything that comes their way? Heck, they even posted one of my submissions recently.
Is there a layer-by-layer break out some place? The way they have all the layers on top of each other in the PNG makes it very hard to tell what's going on in the red-colored layer. The yellow layer at least looks pretty simple, though the fact that the QFN's epad doesn't appear to be grounded strikes me as a bit questionable. A lot of IC's rely on downbonds to ground internal pads. Leaving them floating is a big no-no. While they'll probably find alternate paths to ground, they're not the sort of paths you want to rely on.
I can say from the photo in their forum that the through-hole stuff is indeed debug, unless they actually plan on having a 5x2 header on the final release, which would be pretty pathetic and lead to lots of accidental finger-stabbings. They have plenty of empty space once you move away from the IC footprints, so having some non-populated headers won't cost them anything.
With that in mind, they revealed the final board is exactly the same size as a credit card, measuring 85.65 x 53.98mm."
And it's name will be Selma
Shai Schticks:"You don't make peace with friends, you make peace with enemies"
Really, SMD is not hard to solder, you just use different techniques with your old tools.
Sure, BGA is out of the picture for most people, but SOIC, TQFP, SSOP/MSSOP and parts down to 0402 are still hand-solderable. You just have to make the mental shift away from thinking "OMGZ, It's surface mount, I'll never be able to solder that!". In many ways SMD is a lot easier and simpler, because surface tension becomes your friend.
Of course, failing that, go get a skillet and some solder-paste or convert a pizza oven into a reflow chamber. I for one am happy to never deal with pin-through again.
All the originals are still available from somewhere, lol.
The new families of chips are smt, but you can do those with a syringe of solder paste and a heat gun. :)
It works for most stuff except for bgas.
It take a bit of practice to get just right; I started practicing on smt stuff in '86. iavo, lol.
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I think the biggest thing that can come out of this project (especially if more like it come around) is the fact that the hardware is too cheap to run a non-free OS on it. Now sure, to make it into a full computer you have to add a monitor, keyboard, mouse, USB hub, storage (not sure if it comes with flash built in or if it needs a SD card to boot from), and and Internet connection. But most people are going to see the $25 price (assuming something like this ever gets retail) and pick one up. The netbooks almost made this happen (since they were Linux only when they first came out -- until Microsoft cut a deal for Windows XP). Only thing is, would the typical user be using a Debian based (or similar) distro, or would they be using a version of Android?
The only thing I think that would make this more useful is if they added another, say, $30 or so to the price and added a calculator screen / keypad to it (and battery/charging circuitry). Since most high school kids need a $100 graphing calculator, one that transforms into full workstation when plugged into a monitor/keyboard would be great. Of course the schools probably would never allow the use of an "open" calculator on exams (but then again, most high school level exams only need a simple scientific calculator -- or a slide rule).
You talk as though the Pi is feeble. It's a staggeringly powerful computer. Better than a workstation of a few years ago or a supercomputer of a few decades ago. You know, the kinds of things they used to design jet aircraft, run accounts for multi-national corporations, invent nuclear weapons, plan space missions, develop models of the universe and stuff. We're just accustomed to almost unbelievably powerful computers.
If you want someone to learn how to code efficiently give them an 8-bit microcontroller, not a 32-bit one-point-something GHz CPU with hundreds of MB of RAM.
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I agree, I wish there was a kit I could buy to build a functional computer that could run a modern Linux distro. I know that they make a kit called "Replica 1" that you can build an Apple I clone, but I wonder if there is something out there more advanced. I was thinking how awesome it would be to assemble something like a Raspberry Pi and put it into a case with a similar formfactor as a ZX Spectrum.
Pick up an AVR and code in C. Not even an ATmega, start with an ATtiny. And to push things even further, I would suggest the ATtiny85 instead of the ATtiny861.
Three words: Tiny, low-cost, MAME.
Most of these chips support in hardware the stuff your average blu ray player or satellite box has to support. But support doesn't mean make available. There are so many patents around these things that the tech is usally masked off and you have to load a token onto the chip at the factory to enable it. So the chip might be capable of a lot of things but you ain't going to be able to use them. I assume h264 is going to be enabled by a token but it would still need the APIs in order to make use of it in hardware. And that would raise some interesting questions about what happens if you invoke those APIs from GPL software, and aside from that how do you go about overlaying graphics over the video buffer while it is playing out.
Give it to a child, plug it into a TV or monitor and a keyboard, and you allow them to be creative.
The software side of things will be intended to push that side of things.
Think OLPC, only not so squarely aimed at the developing world, and assuming that people can source screens and keyboards separately.
Why not?
Because, except for hobby or training, it doesn't make sense.
There was a time when one used lots of 555 chips. Today you have the 12F675 PIC in the same eight pin format that can do almost everything the 555 can do without any external components. A 12F675 cost about $1.60, which is $1 over the price of a 555, but the lack of external components and the added flexibility will compensate for that.
The same can be said of most discrete logic chips. Unless it's a very simple logic function, it makes more sense to use a PIC than to assemble a circuit from TTL or CMOS chips.
C, that's not even trying.
Step 1 : learn AVR assembler
Step 2: write a compiler / runtime / OS or whatever
Step 3 : ????? (debugging)
I asked Rick Perry about a step 4 but he couldn't remember one.
There are places where the networks are not touching,and there are places where they are-Boeing's Lori Gunter
It is also worth mentioning that there are many PCB manufactures and assembly houses that will make a couple of PC boards for you and install all the BGAs DQN, FQN, and power pad packages for you for just a few hundred dollars.
Well I pretty much gave the reason just slightly further down that paragraph; a microcontroller, be that PIC or AVR or whatever one prefers, will do the job much better. However, I should have added "in general".
Yes, the 4000 and 74xx series are still produced and actively used in design. However, check which ones, and why.
A BCD-to-7-segment decoder, for example, makes sense to use simply because they are readily available, cheap, and driving a 7-segment from your microcontroller is a waste of pins and raises power ratings concerns... an alternative is getting a specialized microcontroller that has a 7-segment driver on board.. which of course is more expensive.
But if you look at, say, a serial in parallel out, or a counter, or.. etc. If your design already uses a microcontroller, then adding their functionality in code is much simpler and more flexible. Unless you're running out of memory space, it's the way to go.
I still do 4000 series designs (and specifically the 4000 series as it's more forgiving of mistakes), but only for the specific purpose of teaching kids the basic principles of their function, how to interface them with each other, etc. But in the end, we then go to how we can duplicate each component's functionality in code functions, how those functions can interface with each other, how to streamline them, and get the same result from, say, a 16-pin PIC that the larger board with 12 8-pin to 18-pin + side-components did.
I don't see why there would be any GPL issues. The patent license fees were already paid by the hardware manufacturer, and all the GPL software is doing is sending it a bitstream. What happens to the bitstream after that has nothing to do with the software license.
It would be absurd if there were hardware features of the chipset that could not be used due to being deliberately disabled. For the Raspberry Pi to be workable in a HTPC or media streamer setup, it must support at least VC-1 and MPEG-2 bitstream decoding in addition to H.264. Although they are less intensive to handle in software, I doubt the Raspberry Pi's weak (by modern standards) ARM CPU can handle 1080p23.976 decoding of these formats via software alone.
I'll second that- I shudder when some part has to be through hole. It makes routing harder, and soldering is a bigger pain too.
Oh please! How damned delusional and desparate for users do you have to be that you HONESTLY think people in the west are gonna rush out and by a cellphone GPU based hackers toy?
I'll buy 4. Maybe I'm delusional, but I could do a lot of cool stuff with one of these. Thinking of hooking one to a touchscreen and having it run my CNC.
I mean how fucking sad when your ONLY hope at this point is that China can crank out something so damned cheap that Windows won't fit.
Only hope of what? Windows is irrelevant to me, and whether or not you use Linux is irrelevant to me. I suspect it's irrelevant to most of the people who will develop solutions for these boards.
BTW, you sound bitter, I'm not sure what your point is though. These are awesome little boards targeted at innovators, you don't have to buy one. No one will mind. Or maybe you should buy one and put windows on it, show the world what an awesome OS it is.
The second point is just a digression into how SoCs work. If you look through a chip's specsheet it will claim to support various techs in hardware. But to use them the chip must be loaded with a cryptographic token which unlocks the feature. Normally the STB manufacturer would buy the tokens and load them onto the box in the factory. No token = no access to the feature. So I expect Raspberry Pi will support h264 and HDMI because it's publicly said as much but there is no guarantee it will support other things the chip have the potential to do.
The third was just a throwaway comment but ties into XBMC again. These SoCs usually split the display into layers, e.g. 1 or 2 presentation layers, a subtitles layer, a video layer. So even if you could hardware accelerate the video playback, it would have to tie into the way XBMC or other media players composite their screen. I expect XBMC would probably just use a null video driver and would rely on the APIs to fill in the video layer. Perhaps it might even keep the video playback / trickplay functionality in a separate process to keep itself and the proprietary APIs separate from each other.
many designs actually use them still.
Oh many designs use one or two of them to glue stuff together but other than a few masochists noone builds large systems out of them anymore. The world has moved on, micrcontrollers for the non speed critical stuff, programable logic for the speed critical stuff.
note: i'm known as plugwash most places but i screwd up registering that here somehow in the past and now can't register
Did you even READ the post I was responding to? The guy was so desperate for Linux to gain ANY share he cooked up this scenario where a $25 cell phone GPU caused a "revolution" with people buying this en masse and tossing Windows! Nobody and I repeat NOBODY that uses a modern or even older Windows desktop/netbook/laptop is gonna shitcan their current setup for a $25 cell phone GPU that doesn't even come in a case!
You wanna know why Linux numbers are flatline? Its actually really simple, its because the developers and community won't listen and violate rule 1 of business, give the people what they want or at least what they think they want! Instead to paraphrase a line from Vietnam the whole thing has been taken over by deluded zealots that truly believe 'inside every user is a C programmer waiting to get out' like Suzy the checkout girl is reading Bash programming manuals in the bathtub and grandma is working on her CS degree in between knitting classes, its fucking nuts!
Look, if you want to be a hobbyist OS for programmers? I have NOTHING against that, in fact I ran OS/2 for years after everyone else had bailed. But coming up with one delusional scenario after another just makes your OS look like the property of the "Elvis is alive, NASA faked the moon landing" tinfoil hat wearing nutters. When I am having a conversation with a 15+ year Linux server admin who runs a giant server farm for a living and they tell me when i ask what distro to try as a final gasp before giving up and they say "As soon as I'm backed up i'm going to FreeBSD and if that doesn't cut the mustard I'm giving up on FOSS desktops and going Mac or Windows" you KNOW the shit is fucked up.
Fix the driver borkage (Protip: everyone else from BSD to Solaris has had a hardware ABI for nearly a decade, you think you are smarter than every OS designer on the planet?) and make an OS that will pass my "Is it safe?" test, where I simulate a user having the machine for 3 years by downloading the distro from 3 years ago and updating to current (which of course causes it to fall down like a house of cards) and then we'll talk. Keep predicting that some niche device will magically make people see bash prompts and programming as "the next big thing" and we'll all laugh at you and you'll stay flatline, kinda like...well right now actually. Kinda sad when MSFT puts out Vista, one of the most hated of their OSes EVAR, and you can't even gain a single percentage point. that is just sad man, totally sad and pathetic.
ACs don't waste your time replying, your posts are never seen by me.
About the only time I'm appreciative of PT on a board is if I'm trying to route a power rail and I can use the leg/pin as an implied via, but overall, yep... PT is a PITA. :D (not to mention how it slows up assembly so much!)
Did you even READ the post I was responding to? The guy was so desperate for Linux to gain ANY share he cooked up this scenario where a $25 cell phone GPU caused a "revolution" with people buying this en masse and tossing Windows! Nobody and I repeat NOBODY that uses a modern or even older Windows desktop/netbook/laptop is gonna shitcan their current setup for a $25 cell phone GPU that doesn't even come in a case!
Well, yeah, I did, I didn't get the same read on it. Or maybe I thought your post was a bit over the edge because I don't really care if anyone uses Linux as long as I can. Personally I don't feel the drive for everyone to use Linux. I do appreciate that it gets more development with more exposure, but basically UNIX is a developers toolkit, I'm a developer and I love Linux. Perhaps the original poster was a bit enthusiastic, but you went ballistic.
You wanna know why Linux numbers are flatline? Its actually really simple, its because the developers and community won't listen and violate rule 1 of business, give the people what they want or at least what they think they want! Instead to paraphrase a line from Vietnam the whole thing has been taken over by deluded zealots that truly believe 'inside every user is a C programmer waiting to get out' like Suzy the checkout girl is reading Bash programming manuals in the bathtub and grandma is working on her CS degree in between knitting classes, its fucking nuts!
The US accomplished everything they set out to in Vietnam.
Regarding the rest, I concur, I think that trying to make Linux a desktop for everyone basically cripples it. But I can run whatever distro I want, and they aren't all trying to do that.
Look, if you want to be a hobbyist OS for programmers? I have NOTHING against that, in fact I ran OS/2 for years after everyone else had bailed.
Regarding OS2, good for you! I never really did anything with it. I did set it up though. OTOH, hobbyists are perfect candidates for Linux. I have to disagree with you there.
But coming up with one delusional scenario after another just makes your OS look like the property of the "Elvis is alive, NASA faked the moon landing" tinfoil hat wearing nutters. When I am having a conversation with a 15+ year Linux server admin who runs a giant server farm for a living and they tell me when i ask what distro to try as a final gasp before giving up and they say "As soon as I'm backed up i'm going to FreeBSD and if that doesn't cut the mustard I'm giving up on FOSS desktops and going Mac or Windows" you KNOW the shit is fucked up.
Well, I built an ISP with Linux in '93, when it barely worked, and now it runs the internet. I still build my own server farms, although I'm not really a sysadmin. (OK, I built an ISP, but that was just to get on the net.) I'd have to say that your buddy must be a little slow, if he can't cut it with Linux, he probably should look for work in either the food service or hospitality industries.
Now, I build air traffic control systems with it. Avoid Heathrow, Sidney(+), Hong Kong, Dallas, Scandinavian countries, Dubai, and any Canadian airport because they all run our stuff. I'm Canadian and believe it or not, we win awards for this shit, we were on top three out of the last four years. Air Nav customers will not run Windows anymore, they all agree that it was basically a mistake to use it in the first place. It just doesn't cut it. Can't speak for hobbyists.
Fix the driver borkage (Protip: everyone else from BSD to Solaris has had a hardware ABI for nearly a decade, you think you are smarter than every OS designer on the planet?)
Me, no, but I'm up there. Then again, that isn't what you meant.
and make an OS that will pass my "Is it safe?" test, where I simulate a user having the machine for 3 years by downloading the distro from 3 year