OLinuXino, a serious Rasberry Pi competitor? - Page 3

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Re: OLinuXino, a serious Rasberry Pi competitor?

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Chinese mediaplayer I have,
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Sorry, but that is pure theory. In reality 99% of the PCs will happily
deliver >1A through their USB port. Current regulation circuitry and
controlling it adds extra costs and customers might think their PC is
broken because the devices are not working or are not getting charged.
Manufacturers want to avoid that extra hassle.

I just tested a USB port of my PC with a dummy load and it supplies
over 1A without a device attached.

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Re: OLinuXino, a serious Rasberry Pi competitor?
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The only computers I've seen complaining about USB current consumption is
Macs, both desktops and laptops, and running both OS X and Windows. You get
this nice loop where the OS turns off the host port, pops up a warning
dialog, automatically turns the host port back on, turns it back off again,
pops up another dialog etc. I was still dismissing dialogs for almost a
minute after yanking out the device.

-a

Re: OLinuXino, a serious Rasberry Pi competitor?
snipped-for-privacy@kapsi.spam.stop.fi.invalid says...
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In last two years seen at least three Win PCs complain about it.

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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?
On a sunny day (Fri, 9 Mar 2012 21:33:04 +0000 (UTC)) it happened
snipped-for-privacy@kapsi.spam.stop.fi.invalid wrote in

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Right, when I plugged the little Chinese mediaplayer into my PC, battery empty,
I heard a ticking noise.
It was coming from the player, charging, power disconnect, off, on (tick)
charging, power disconnect, off, on (tick)....
:-)

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.

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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.

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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.

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<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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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.

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