jamesh
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Re: if its good copy it?

Mon Dec 19, 2011 12:03 pm

[quote]Quote from Piw32 on December 19, 2011, 03:35
Preorders are piling up : http://rhombus-tech.net/recentchanges/[/quote]

Let\'s hope they get the >100k units they will need to get anywhere near that pricing then!
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Re: if its good copy it?

Mon Dec 19, 2011 12:08 pm

Companies from PRoC usually ignore all sort of patents and correspondent payments of licence fees... Well in my opinion that is ok because patents complicate all sorts of research and development... And I think it is possible to create such device for mentioned parts price. But end customers won\'t see it for less than 50$.

Which is in my opinion same price as raspberry-pi after vat, customs, shipment...
And that is only for device (rpi) itself without peripheral devices.

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Re: if its good copy it?

Mon Dec 19, 2011 1:15 pm

[quote]Quote from hajj_3 on December 19, 2011, 11:22
Here is the FULL specs and block diagram for the Cortex A8 Allwinner A10 chip: http://www.allwinnertech.com/product/a1x.html[/quote]
[quote]DPU

MULTI-CHANNEL HD displays
Built-in HDMI
YPbPr, CVBS, VGA
[/quote]

Yes !!!

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Re: if its good copy it?

Mon Dec 19, 2011 1:27 pm

I wonder if the people designing the board will bring out the VGA? or decide there are other more important interfaces to add. Remember, this is a small board and space limited for connectors. The Raspi has the same problem, there are a limited number of connectors so not all interfaces are pushed out.

I\'d add VGA if I were them.
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Re: if its good copy it?

Mon Dec 19, 2011 1:51 pm

[quote]Quote from jamesh on December 19, 2011, 12:00
I cannot tell what the 3D performance is like.[/quote]

It has the: MALI400MP OpenGL ES 2.0 GPU http://www.arm.com/products/multimedia/ ... 400-mp.php

according to: http://rhombus-tech.net/allwinner_a10/

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Re: if its good copy it?

Mon Dec 19, 2011 1:58 pm

[quote]Quote from jamesh on December 19, 2011, 13:27

I\'d add VGA if I were them.[/quote]

Yes, i was looking for a videoprojector, those with a HDMI input cost 200€ more than VGA and Composite ones.

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Re: if its good copy it?

Mon Dec 19, 2011 3:14 pm

[quote]Quote from tntexplosivesltd on December 18, 2011, 08:11
see also

http://elinux.org/Embedded_Open_Modular ... ion_1.0.29
[/quote]

The PCMCIA connector brings out parallel RGB signals that can be used however you like. A video DAC gives you VGA, or you can serialize into LVDS or HDMI. By \"you\", I mean whoever comes up with the adapter board that the Embedded Open Modular Architecture/PCMCIA card plugs into. It\'s easy enough for a hobbyist to create a PCB to do this and have it manufactured for US$50 or so, but that kind of defeats the idea of a US$15 computer, doesn\'t it?

As I said earlier in the thread, nice form factor. I\'ll be interested in seeing if it catches on, or goes the way of the Flash MiniCard (sigh) and so many other promising form factors.

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Re: if its good copy it?

Mon Dec 19, 2011 8:06 pm

[quote]Quote from obarthelemy on December 18, 2011, 19:14
@emercer: hey, great to see you. It does have the 68-pin connector, but it\'s not PCMCIA-compliant in the sense that they\'re using it as a system bus, not a PC expansion card. The connector carries Sata, USB, Video... so you need a specific host board to stick that into.[/quote]

Good to see you here as well obarthelemy (long time, no see!) That is why I mentioned the EOMA PCMCIA \'standard\', which is a re-purposing of the PCMCIA interface and form-factor as an Embedded Open Modular Computing Module. Version 1.0 includes a proposed pinout for use as a system bus (including deliberate mechanical non-interoperability measures).

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Re: if its good copy it?

Thu Dec 22, 2011 6:22 am

Just looking quickly I found two lower end ARMs that would fit the price bill at Arrow, given that they are planning on volume it should be no trouble for them to get the price comparable (though I would love to know where they get there DDR2SDRAM for that price). The two low end ARMs in question are at:
http://components.arrow.com/part/detail ... 14601N7713
and:
http://components.arrow.com/part/detail ... 35313N3744

I must assume in order to keep the price down they are using simple double sided boards, and there pictures seem to confirm this.

Before anyone says it:
I do a lot of electronics boards at home and I know that it is possible to make a board with BGAs of that type of density using a simple two layer design, so long as it is less than 7 rows of balls, and the ball pitch is greater than 0.4mm.
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Re: if its good copy it?

Thu Dec 22, 2011 10:50 am

I think they would have trouble making a board with two layers and getting all the interfaces out. We needed to use a 6 layer board on the Pi to route everything to the edges.
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Re: if its good copy it?

Thu Dec 22, 2011 11:16 am

Sounds like a great project but I think there is a fair way to go before they are at the point where they have hardware to sell. Good luck to them, although I doubt there will be anything for at least 12 months probably.
Fingers crossed the R-Pi will be out soon. Considering what kind of success the R-Pi should be, there will be plenty of room for similar products for different uses (In particular ones which can do Android or similar).

I\'d be surprised if they can do it with a 2 layer design, but I\'m no PCB engineer, I imagine the ground-plane layer alone is kinda required, not to mention dealing with the high-speed signals cleanly.
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Re: if its good copy it?

Thu Dec 22, 2011 2:11 pm

Yes it would be difficult to lay out something like this on a two layer board, though have you looked at there layout, not very dense. Though I do know from experience (on the hobby side) that it is possible. And yes it would be difficult to have clean signals on a two layer board, though it could still be usable.

Personally I am for the Raspberry Pi.
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Re: if its good copy it?

Thu Dec 22, 2011 2:59 pm

It was very difficult doing the layout for the Raspi on 6 layers, and since this has, I presume more interfaces to the outside world, the layout is even more complicated.
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Re: if its good copy it?

Thu Dec 22, 2011 3:28 pm

The great thing about vaporware is that it can be routed on any number of layers you like. Perhaps they mean two signal layers, i.e, all signals on the outer two layers with four layers total. Even that is hard to achieve unless you have lots of routing room around chips and/or chip pinouts that match connectors, for example chips with PCI interfaces. With EOMA/PCMCIA, just getting those 26 LCD signals from a BGA SoC to the PCMCIA connector could be nasty.

Plus you have to be careful about through-board vias. If you have too many they may break up the ground plane: the \"Swiss cheese\" effect.

Edit: BeagleBone is similar to EOMA/PCMCIA in terms of board size and which signals are brought out to connectors. It has a discrete DRAM chip, and uses a larger SoC package with lower BGA density, simplifying routing. Even so, BeagleBone has 6 layers just like RasPi.

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Re: if its good copy it?

Thu Dec 22, 2011 4:01 pm

Why is it that people assume that just because most do it a certain way that this is the only way it can be done? The home made ARM board that I am currently using has a 2 x 217BGA SoC, an external DDR2-SDRAM, NAND FLASH, A VGA RDAC, an ethernet module, 2 x USB, and exports the RGB and sync lines and 50 GPIOs. And this is just something that I threw together in a couple days to get me by until the Pi comes out. This was done with a 2 sided board, on one side all the extra space between traces is used for a ground plane the other side the same for a power plane. It has problems, it is far from the best, and it is slow (SoC 400MHz, bus 133MHz).
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Re: if its good copy it?

Thu Dec 22, 2011 4:03 pm

The key is the old school rule: try to keep most lines on one side 1 direction and the other side 90 degrees from the first.
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Re: if its good copy it?

Thu Dec 22, 2011 4:12 pm

The reason most do things a cetain way is because its the best way - especially when you re talking about keeping the costs down.

Here is a picture of the underside of a 2727 Videocore 3 chip. The BRCM2835 on the Raspi has more balls but the same pitch. If you can lay that out on 2 layers, go for it. It would save the foundation quite a bit of cash, as 6 layer boards are expensive in comparison.

[IMG]http://i175.photobucket.com/albums/w143 ... 01-018.jpg[/IMG]
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Re: if its good copy it?

Thu Dec 22, 2011 4:40 pm

Wow that looks like a fairly fine ball pitch (or a huge finger). What is the pitch? Also is the BRCM2835 available in a package with a wider ball pitch at a comparable cost?

I would love to help, for a future version of the board. But that looks to be finer of a ball pitch than I have ever dealt with.
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Re: if its good copy it?

Thu Dec 22, 2011 4:48 pm

I Respect very much the work being put into the Raspberry Pi, and think that you are doing an excellent job. I am only mentioning possibilities as to how the other may be doing it.

In my experience there does tend to be a good bit of signal noise on two layer boards in these applications. Just because I feel that it is highly probable that the others may be doing this does not mean that I think that there boards will be up to the quality of the Pi.

I may see how much my board can be redone to reduce the noise difficulties and if it turns out to be feasible I will submit a design to Raspberry Pi for a lower end board. As if done with a single SoC the high volume costs of producing my through together board are probably right around $15USD, it cost me a good bit more, though I used single quantity components and did not bother to order those that I could get from Radio Shack.
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Re: if its good copy it?

Thu Dec 22, 2011 5:19 pm

[quote]Quote from DavidS on December 22, 2011, 16:40
Wow that looks like a fairly fine ball pitch (or a huge finger). What is the pitch? Also is the BRCM2835 available in a package with a wider ball pitch at a comparable cost?

I would love to help, for a future version of the board. But that looks to be finer of a ball pitch than I have ever dealt with.[/quote]

It\'s about 0.3mm IIRC. I think it\'s only available in that sort of pitch - nothing bigger as it\'s the size needed for mobile devices. Also get more expensive to package the larger you go. These sorts of devices are only intended for pick and place robots. I can sell you one for £25k second hand if you are interested...1800 components per hours.

It\'s my finger, as far as I know it\'s a standard size.
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Re: if its good copy it?

Thu Dec 22, 2011 5:32 pm

[quote]Quote from jamesh on December 22, 2011, 17:19
[quote]Quote from DavidS on December 22, 2011, 16:40
Wow that looks like a fairly fine ball pitch (or a huge finger). What is the pitch? Also is the BRCM2835 available in a package with a wider ball pitch at a comparable cost?

I would love to help, for a future version of the board. But that looks to be finer of a ball pitch than I have ever dealt with.[/quote]
It\'s about 0.3mm IIRC. I think it\'s only available in that sort of pitch - nothing bigger as it\'s the size needed for mobile devices. Also get more expensive to package the larger you go.
[/quote]
And why stick with the lower ball count stuff (less than 400 balls).
[quote]
These sorts of devices are only intended for pick and place robots. I can sell you one for £25k second hand if you are interested...1800 components per hours.
[/quote]
No thanks, I will stick to devices having 0.5mm or greater ball pitch (stuff that can be done at home).
[quote]
It\'s my finger, as far as I know it\'s a standard size.[/quote]
LOL.
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Re: if its good copy it?

Thu Dec 22, 2011 5:34 pm

That\'s peaster egg #1. James giving us the finger.

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Re: if its good copy it?

Thu Dec 22, 2011 7:16 pm

[quote]Quote from DavidS on December 22, 2011, 16:01
The home made ARM board that I am currently using has a 2 x 217BGA SoC, an external DDR2-SDRAM, NAND FLASH, A VGA RDAC, an ethernet module, 2 x USB, and exports the RGB and sync lines and 50 GPIOs. And this is just something that I threw together in a couple days to get me by until the Pi comes out. This was done with a 2 sided board, on one side all the extra space between traces is used for a ground plane the other side the same for a power plane. It has problems, it is far from the best, and it is slow (SoC 400MHz, bus 133MHz).[/quote]
That\'s very impressive. Do you have images you could post? Which SoC are you using?

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Re: if its good copy it?

Thu Dec 22, 2011 7:25 pm

They are Atmel SAM9G15 chips, with a 0.8mm ball pitch. It is amazing that it only took me one try to get it working.

As to pictures I guess that some day I will have to buy a camera (it seems like this request is becoming more and more common).
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Re: if its good copy it?

Thu Dec 22, 2011 7:26 pm

Though I would note that this is a very simple chip to work with on the HW level.
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