On a sunny day (Tue, 06 Mar 2012 17:34:37 +1100) it happened keithr
<
ke...@nowhere.com.au> wrote in <4f55affe$
1...@dnews.tpgi.com.au>:
>>> It seems to me that there is a good deal of fear and loathing about the
>>> Pi from entrenched interests.
>>
>> Me? Fear and loathing? No, disappointment. I'd *love* to see something that
>> would get kids interested in electronics again. I'm close enough to
>> retirement that they're not a threat to my lunch (which has benefited
>> immensely from the lack of kids' hardware skills). ;-)
>
>Not necessarily you, but there are several posters in this thread who
>have a vested interest is selling similar products, and they seem to be
>the ones questioning the project.
I dunno.
I am retired, and am very critical of this so called 'educational' thing.
There is no educational aspect in it any where.
Some closed source toy with closed binary drivers, hardly any I/O,
missing keyboard, missing power supply, and missing a good book that explains
computahs, electronics basics, programming basics, no display, not even
a decent housing, how long will it live with 'kids' who put it on the table
next to the metal ballpen or whatever, static discharges from rubber shoes,
It is all hype.
Press will publish any release you send them, including flying cars
and what not.
So what age group is this targeted at?
Do they even have a soldering iron, some scope? You NEED that.
And the youngsters that DO have access to that stuff will likely get a board
with chips that have full documentation so they can get the maximum out of their toy.
This strawberry pie has had far too much media exposure,
The Microchip PICs were and are extremely popular with the younger generation
because they have decent datasheets, are easily programmable, and
are available almost everywhere locally.
As Don pointed out there are small boards with PICs too that run Linux for those
that want that (for many projects you do not need a top heavy multitasker).
PICs are cheap too.
Look here for some projects I did with PICs:
http://panteltje.com/panteltje/pic/index.html
Some are not so simple, some if not all require a PC, if only for programming.
Now let's look at the strawberry or whatever cake.
That Broadcom chip is actually a media player chip.
If you just install Linux and perhaps run the X server, then forget about the media player
aspect, because ***X runs at a fixed H and V resolution***.
Let's get a bit technical, after all this is a design group, many Linux enthusiast are here
too.
I recorded (with Linux and MY software) last night some DVB-S2 HD movie from Germany ZDF
via satellite:
-rw-r--r-- 1 root root
16006144000 Mar 6 00:58 spy_game_2001_german.ts
Now let's look at the format this is transmitted in, and what is in there:
panteltje10: /video/satellite # mediainfo spy_game_2001_german.ts
General
ID : 3F3
Complete name : spy_game_2001_german.ts
Format : MPEG-TS
File size : 14.9 GiB
Duration : 2h 41mn
Overall bit rate : 13.2 Mbps
Video
ID : 6110 (0x17DE)
Menu ID : 11110 (0x2B66)
Format : AVC
Format/Info : Advanced Video Codec
Format profile : Main@L4.0
Format settings, CABAC : Yes
Format settings, ReFrames : 5 frames
Duration : 2h 41mn
Bit rate : 11.2 Mbps
Width : 1 280 pixels
Height : 720 pixels
Display aspect ratio : 16/9
Frame rate : 50.000 fps
Resolution : 24 bits
Colorimetry : 4:2:0
Scan type : Progressive
Bits/(Pixel*Frame) : 0.244
Stream size : 12.6 GiB (85%)
Audio #1
ID : 6120 (0x17E8)
Menu ID : 11110 (0x2B66)
Format : MPEG Audio
Format version : Version 1
Format profile : Layer 2
Duration : 2h 41mn
Bit rate mode : Constant
Bit rate : 256 Kbps
Channel(s) : 2 channels
Sampling rate : 48.0 KHz
Resolution : 16 bits
Video delay : -1s 263ms
Stream size : 295 MiB (2%)
Language : German
Audio #2
ID : 6121 (0x17E9)
Menu ID : 11110 (0x2B66)
Format : MPEG Audio
Format version : Version 1
Format profile : Layer 2
uration : 2h 41mn
Bit rate mode : Constant
Bit rate : 192 Kbps
Channel(s) : 2 channels
Sampling rate : 48.0 KHz
Resolution : 16 bits
Video delay : -1s 216ms
Stream size : 221 MiB (1%)
Language : qaa
Text #1
ID : 6130 (0x17F2)
Menu ID : 11110 (0x2B66)
Format : Teletext
Language : German
Text #2
ID : 6131 (0x17F3)
Menu ID : 11110 (0x2B66)
Format : DVB Subtitles
Language : German
Menu
ID : 6100 (0x17D4)
Menu ID : 11110 (0x2B66)
List : 6110 (0x17DE) (AVC) / 6120 (0x17E8) (MPEG Audio, deu) / 6121 (0x17E9) (MPEG Audio, mis) / 6122 (0x17EA) (AC-3, deu) / 6123 (0x17EB) (MPEG Audio, qaa) / 6130 (0x17F2) (Teletext, deu) / 6131 (0x17F3) (DVB Subtitles, deu) / 6170 (0x181A) ()
Language : / deu / mis / deu / qaa / deu / deu /
------------------------------------
That is the transport stream for this transmission.
You will notice (perhaps) that the format is 1280 x 720 @ 50 fps progressive.
If you want to play this in X with for example mplayer, EVEN if it has all the codecs,
then theoretically the X server would have to refresh frames as 50 Hz IN SYNC with the video.
That is for a MEDIAPLAYER, and that is one thing they claim it can do.
Unfortunately X does NOT sync to the video framerate, so it will NORMALLY tare frames
and drop frames at random, even if you add a modeline for 50 Hz.
The fact with MEDIAPLAYER chips is that the CHIP does the grabbing of the next frame from memory, decodes it,
displays it, and then grabs the next frame.
I am sure this chip can do that, but can the standard Linux that comes with this thing
support that feature?
To give some idea what the actual problem is here, read this thread please:
http://linuxtv.org/pipermail/vdr/2008-July/017347.html
So, as far as I can see, and that is not far in this case as most of that stuff is closed
source, as a MEDIAPLAYER this thing is not very usable.
And you cannot FIX it because it is closed source.
It seems to come with Fedora Linux, now that is RatHead (had to drop that one on you) Linux,
and it will be incompatible with the rest of the universe by design anyways,
I'd love to be proven wrong, but the above issue make it a nono for me,
it already is a nono for the simple fact that PICs are more suited for small projects,
can be programmed in asm, close to the hardware, and then are faster, boot faster,
more reliable than Linux for simple control operations like, as some person mentioned,
controlling things around the house or some robotics or what not.
The ONLY reason I would want a strawberry cake would be a REAL multimedia player,
or if it actually had WiFi.., as that would add to the spectrum of what you can
build in a few days, but I already have several Linux boxes, some far more advanced
than that hype thingy, so,
And then to teach kids about electronics, maybe Winfield's The Art of Electronics is a bit
too high a level for them to start, give them some transistors and an Ohm meter,
some batteries, LEDs, the works.
To teach them about PROGRAMMING give them a laptop or PC.
maybe the OLPC.