OLinuXino, a serious Rasberry Pi competitor? - Page 3

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Re: OLinuXino, a serious Rasberry Pi competitor?
On a sunny day (Fri, 09 Mar 2012 20:14:36 GMT) it happened snipped-for-privacy@puntnl.niks

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Chinese mediaplayer I have,
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Well, mine crapped out at a much lower current.
It is just that ignoring specs that makes that strawberry pudding a request
for disaster.

Re: OLinuXino, a serious Rasberry Pi competitor?
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 > Adds an other 5$ at least even if DIY.

I suspect the strategy is to tell people to just go buy a cigarette
lighter (12V) to micro-USB power adapter on eBay for literally a buck or
two shipped to your door.  (I just found one for $0.99 shipped from
Taiwan, 5V @ 1A output...)

Re: OLinuXino, a serious Rasberry Pi competitor?

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Is this a hard spec or do they just say that to make it simple. I see
a 3.3V regulator close to RP's power connector.

--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
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Re: OLinuXino, a serious Rasberry Pi competitor?


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the core runs off that regulator, the USB socket and the expansion
connectors have the input power directly connected.  The ethernet and
the onboard USB hub may need 5V.

--
⚂⚃ 100% natural

---

Re: OLinuXino, a serious Rasberry Pi competitor?
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Very unlikely anything needs 5 volts other than the USB connector
assuming it is a HOST connector for mice, keyboards, etc.  But even
then the 5 volt port will not need a tightly regulated 5 volts, it
just needs to be within the input spec... which is somewhat tight at
4.75 to 5.5 volts typically.  But to be sure you would need to check
the data sheets for the parts in question.  Since there is no
schematic available currently, can't do that.

Rick

Re: OLinuXino, a serious Rasberry Pi competitor?
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There are LOTS of car adapters that provide a 5 volt USB socket, just
add standard cable...  Mail order places have them for under $5.

Rick

Re: OLinuXino, a serious Rasberry Pi competitor?
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Word from partner who IS a teacher of ICT and computing in UK, if they
want embedded in schools (which is sadly lacking in UK) they should
contact and get involved with Computing At School group/seminars/conf
in UK.

Plenty of open source followers there.

If need more info I can get details for you.

--
Paul Carpenter          | snipped-for-privacy@pcserviceselectronics.co.uk
<http://www.pcserviceselectronics.co.uk/ PC Services
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Re: OLinuXino, a serious Rasberry Pi competitor?

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Exactly. What I'm looking for is the Embedded Linux Computer with FPGA
connected directly to the CPUs bus and to 0,1" headers, so that my
students could deal with different peripherals (implemented in the
FPGA)
and connected to simple circuits assembled on the breadboard (or on
prototype PCB connected via flat cable).
Does anybody knows about such cheap boards?
--
TIA & Regards,
WZab

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Re: OLinuXino, a serious Rasberry Pi competitor?
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No, but keep in mind here that some Linux-capable CPUs these days are
pretty fancy (caches, superscalar, etc.) and have CPU busses that are
non-trivial to interface too -- it's a lot more complex than the old
days of data, address, and a R/W strobe.  Similarly, many CPU busses are
fast enough that you might not get away with ribbon cables anymore
unless you're running, e.g., every other wire as ground.

So just be careful to avoid those for your purposes. :-)

(In a modern PC, while things like PCI cards are memory-mapped, when
someone writes a line of code as simple as *MyDeviceRegister =
0xdeadbeef, what actually happens is a very complex transaction between
the CPU, its local bus, the north bridge, the PCI bus, and whatever chip
is on the target PCI device.)

Re: OLinuXino, a serious Rasberry Pi competitor?
W dniu 09.03.2012 20:45, Joel Koltner pisze:
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Well, I know it. In our team we've dealed with PCI and PCI-e from both
sides - at PC level and at FPGA level.

However for didactic purposes it is good sometimes to let students to
work with hardware, which is directly coupled to the CPU bus
(like EBI in ARMs) before they start to deal with more complex
buses like PCI.
--
Regards,
WZab

Re: OLinuXino, a serious Rasberry Pi competitor?

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Don't count on connecting a CPU bus. Those days are long gone. The
speeds are too high. DDR and flash memory usually have dedicated
busses. Even if you could craft something that resembles a memory bus
there are many issues to work out. Especially if you would make the
bus go over headers. Nowadays you'd use GPIO, I2C, SPI or USB.

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indicates you are not using the right tools...
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Re: OLinuXino, a serious Rasberry Pi competitor?
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Why do you think so? E.g. in a board based on AT91SAM9G45
( http://www.atmel.com/Images/doc6438.pdf ) you can easily connect
DDR
RAM to dedicated pins (DDR_A* DDR_D* etc.) and use separate EBI
pins to connect FPGA.

We have created such prototype a few years ago
( http://www.ise.pw.edu.pl/~wzab/artykuly/fpga_edu.pdf ), but now
it could be done much cheaper, and provide much better parameters.

The idea is to have a single hardware configuration, which may be
configured to have an PC working with simple bus connected peripheral
or with complex Bus Mastering DMA capable peripheral, or a
peripheral connected via ISI, I2S, SPI or whatever else.

--
Regards,
Wojtek

Re: OLinuXino, a serious Rasberry Pi competitor?

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That device is relatively slow. IIRC about the same device is used on
Conitec's Eva board.

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Re: OLinuXino, a serious Rasberry Pi competitor?
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The card described here sounds a lot less powerful than the Pi - slower
processor, too little ram, poor choice of video output ("TV Video" ?),
and weaker graphics and media acceleration.  I don't know that it could
be a "serious competitor" to the Pi with those specs and price, unless
there are outstanding benefits (like being easily available!).

It's a nice idea and initiative, but I don't see it going anywhere.
These boards need community support - there are lots of groups who have
ported different Linux distributions and software for the Pi.  Part of
the reason is that it is non-profit - it appeals to free software
developers.  It will take a lot more to persuade these people to do the
same thing again, only for less exciting hardware with more limitations,
and to benefit a commercial company that is making these boards for
profit.  It helps that Olimex is providing all design files, and is
clearly making these as low cost as possible - but being a charity beats
even the nicest of companies in these rankings.


I think there is a market for devices like this, but they should start
with the Pi's specs and fill in the gaps, not start with the Pi's price
or size and rigidly stick to that budget.  If you took a Pi, added 4 GB
NAND flash, WiFi, Bluetooth, several USB ports, an external power
supply, and perhaps even a cheapo case, you would have a wonderful
device.  It would cost twice as much - but it would be worth it.



Re: OLinuXino, a serious Rasberry Pi competitor?

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The (community) support is already there. Freescale has all the
software (Linux and Win CE BSPs) and documentation on their website
and offers several fora to users.

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Re: OLinuXino, a serious Rasberry Pi competitor?
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Support from Freescale is something totally different from community
support.  It's a good start, but it is not the same.  It just means that
the basic BSP is in place for Android, Linux and Wince of some
particular version.  There is no guarantee that any of the changes,
patches, drivers, etc., make their way back to the mainline.  There is
no guarantee that the anything will be supported in future versions.
There is no guarantee that source will be available for third-party work
commissioned by Freescale, or that the source that is provided is
suitable for future use, or that there will be support in the future.  I
have seen these sorts of problems before from Freescale, where we had an
iMX evaluation card.  It came with a Linux build and BSP.  But the chip
had a graphics accelerator, and the driver for that was partially closed
source, and developed by a third-party (paid for by Freescale).  So we
had to choose between keeping the out-of-date Linux kernel provided with
the BSP, or compiling a new kernel but losing the accelerated graphics.
  Freescale would not pay the third-party to update the graphics drivers
- they were already promoting the next iMX chip instead.  I don't know
if Freescale has done it better this time, but that's a danger you face
when support is by manufacturer only.

The Pi has /real/ community support - there are already half a dozen
well-known Linux distributions that support it, as well as major
software packages like xmbc.

Re: OLinuXino, a serious Rasberry Pi competitor?

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What is the problem with an 'out of date' kernel? If it works, it
works. Bug fixes can often be backported without much problems.

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The same goes for any PC videocard.

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I see the same problem with the RP if Broadcom doesn't provide a new
graphics driver.

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Re: OLinuXino, a serious Rasberry Pi competitor?
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And when it doesn't support newer hardware, it doesn't support newer
hardware.  Bug fixes, and in particular newer features and drivers, can
/not/ be backported without a lot of effort.

In our particular case, we wanted support for a particular wireless
interface.  I wasn't directly involved, so I don't know the details, but
we were faced with the choice of decent graphics or wireless connection,
but not both without a great deal of time and effort.

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No, the same does not apply to PC video cards for two reasons.  One is
that the third-party work commissioned by Freescale was badly done, and
very tightly tied to the kernel version (so much so that it raises
immediate suspicions of gpl violations).  Secondly, Freescale dropped
all efforts to support and update these drivers as soon as they had
started promoting the next version of the iMX device.

In the world of PC video cards, there is a better (though far from
perfect) separation between the closed-source drivers and the kernel,
the manufacturers make drivers to support a range of video cards and
usually keep support for older cards in their newer drivers, and they
try to keep reasonably up-to-date with kernel changes.

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Yes indeed, this could well occur, and it is a risk with the way
Broadcom is doing the drivers for the graphics unit (rather than
providing documentation for an open-source effort).  We can only hope
that the Pi will help put pressure onto Broadcom to release its drivers
as open source, or to provide the required documentation to let others
write drivers.  It has happened with some of Broadcom's WiFi drivers,
and may happen here too.

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Well, "if it works".  We got caught by that with an ARM9 Linux board.  The
manufacturer's plan seemed to be to design bespoke products, then make some
more money by offering the hardware on the open market (nothing wrong with
that idea, IMHO.)  But the original customer got a 2.4 kernel and wanted
nothing more.  USB was the major I/O on the board, and all the really useful
USB features came in kernel version 2.6.  We couldn't upgrade ourselves
because of proprietary SD card drivers.  The original customer didn't want
an upgrade.  The manufacturer wouldn't release an upgrade.  There we were.  
Mini-ITX boards work just fine.

    Mel.


Re: OLinuXino, a serious Rasberry Pi competitor?

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Still some parts of the PI are closed tight, NDA's and that stuff, which
is what turned me completely off after the initial enthusiasm.
So any competition in that field is welcome, especially if it brings more
openness.

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