
The Raspberry Pi Becomes a Form Factor - noonespecial
http://hackaday.com/2013/11/06/the-raspberry-pi-becomes-a-form-factor/
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noonespecial
I'm glad in a way that this is happening. Arduin-ification is an important
step towards ubiquity and 3rd party compatible addons of all kinds.

OTOH, it really is a terrible form factor if you think about it. It's ports
are spread across _every_ edge and surface and even at that, the USB is offset
on its edge just to make it interesting.

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ajross
Honestly, I'm not sure that makes sense to me. Your criteria for "good form
factor" seem to presuppose that the board is going to go into some kind of
standard enclosure. That's not the way these are being deployed -- they're
going in weird custom boxes (or costumes, or stuffed animals...) with a bunch
of other junk. Making the board physically larger just to get all the
connectors on the same edge is going to be a net inconvenience for lots of the
target market.

Obviously for any _one_ device there's going to be a better form factor. But
that's not what the Pi is for.

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zokier
I think you got it entirely backwards. If there was some standard enclosure
then nobody would care where the connectors were. But exactly because it ends
up in all sorts diy projects and enclosures, the crazyish design makes it bad
because it is unnecessarily difficult to design around.

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dade_
Oh please no. It is a terrible design to work with, the screw holes were put
where they fit between wire traces, so random, and they don't provide
sufficient support for the board under the GPIO header (or anywhere else) Then
there are the connectors on every side of the board and the lack of a proper
power connector (no DC jack). USB power supply caused issues consume most of
the forums for the thing. The Pi proved there is a demand for a simple PC at
this price point, there are now several products that are much better and
offer a lower total cost (once accessories are factored in) with many more on
the way.

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lelandbatey
With you mentioning better alternatives, could you list or link to a list of
these better alternatives?

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Lerc
Well there are these, Some better, some worse.

[http://en.wikipedia.org/wiki/List_of_single-
board_computers](http://en.wikipedia.org/wiki/List_of_single-board_computers)

[http://en.wikipedia.org/wiki/Comparison_of_single-
board_comp...](http://en.wikipedia.org/wiki/Comparison_of_single-
board_computers)

I have a cubieboard-2 with a Allwinner A20 (dual cortex-A7 mali 400mp2).
Marginally larger, with sata, onboard flash, also LVDS and vga available from
the pin headers.

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hengheng
Speaking of form factors, I'm really looking forward for a widely-accepted
form factor for living room electronics. Rarely any devices still require
440mm of width, and thus all consoles, set top boxes, sat receivers, small
HTPCs and many stereo amps invent their own. Along with a huge rat's nest of
cabling, this just looks immature.

I'm actually excited for stereo amps, or other home entertainment gadgets, in
raspberry pi format.

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liotier
Stereo amps in Raspberry Pi format ? Even with the latest technology, an
amplifier still require a large and heavy power supply and a no less large and
heavy radiator for the big transistors...

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VLM
The times they are a-changing. The days of class AB amps are pretty much over
for a decade or so now. Its all about the class D amps. From consumer
electronics to cell phones.

This is a simplification, but if you know how a switching power supply works,
what if you took a particularly stable one (switchers are legendarily
unstable, earning the EEs lots of dough) and varied its output voltage in time
with the music waveform, so essentially the switching supply IS literally the
final PA? And that is basically a class D amp.

It takes some pretty modern analog semiconductors (and some decent inductors,
and some PITA simulation and testing) but its reached the point where there's
no real point in deploying older tech unless you've got severe RFI / EMC type
issues to work around or you only need a couple milliwatts.

At the low end you can get twenty or so watts out of a little itty bitty SMD
chip with no heatsink at all (well, the PCB itself..) and a thumbnail sized
inductor (depends how big your thumb is). This is all off the shelf and fairly
conventional. Not if you want to run off line power its a little more
complicated than 12 volts but hardly awful.

I've been working on a little project on the bench that uses the usual line
powered switcher chicom "means well" (the company name, seriously!) and runs
cool as a cucumber at about 300 watts DC out. Now a class D amp as opposed to
a power supply is slightly more complicated, but not much. Its a bit larger,
but lighter, than a 3.5 inch hard drive. Also 300 real electrical watts is
probably well over 2000 watts marketing power, or 2000 watts music power or
whatever scam, so a realistic set of amps for a home theater surround system
is likely a bit smaller. More weight is put into display and controls now than
into the amps.

Another way to think about it is your modern zillion watt PC power supply
basically weight nothing compared to the supplies I was using in the
80s/90s/00s.

Analog electronics is not as boring as some digital types think... there's a
lot going on. For many years there are ham radio guys using a close cousin of
the class-D design to generate a couple hundred watts of HF for peanuts in
something that weights nothing. The day is probably coming in my lifetime
where legacy broadcast transmitters will be a 1U rackmount with a very fat
power cable in, a fat RF connector out, and thats it, no more closets or rack
sized machines just a little 1U box.

(edited to add a link to

[http://www.classeradio.com/8_fet.htm](http://www.classeradio.com/8_fet.htm)

which shows a typical amp of this design.. now don't freak out about 90% of
the image is a variety of RF tuning gear the actual 400 watt 4 MHz or so RF
amplifier is that hockey puck sized PCB in the upper right on the coffee mug
sized heat sink... obviously an audio design would be immensely smaller and
simpler, and 400 watts of real power is like 4000 watts of marketing power, so
you could scale this down a bit...)

(edited one last time to add the interesting anecdote that 30-40 years ago
analog electronics had heatsinks and cooling fans, but CPUs had neither, and
the transposition is basically complete in consumer electronics... analog
stuff no longer uses or needs heatsinks/fans but seemingly all CPUs do, you
could cook bratwursts on my xbox 360 cpu cooling fan, for example but the 500
watt subwoofer loafs along with no heatsink or fan, this would have really
freaked out an electronics guy from 1975, for example)

~~~
foobarian
+1 class D

I used this little breakout board from SparkFun. Room-filling sound when
powering a 4 Ohm 5" car speaker, and the SMD doesn't even get warm.

[https://www.sparkfun.com/products/11044](https://www.sparkfun.com/products/11044)

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malexw
It has hardly become a form factor. This is one company that has designed one
board (which they aren't even selling!) that has the same layout as the Pi.
Calling it a new form factor seems like its jumping the gun a bit.

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aray
Awesome! This chip is the i.MX 6 Quad that's going into bunnie's open source
"Novena" laptop[1]

I've been using the freescale development platform for the chip[2] (SABRE
Lite) to try to follow along with Novena's progress, but my biggest complaint
is that it's too large and oddly shaped to carry around every day.

With this formfactor, I can just put it in a raspberry pi case, and throw it
in a bag without worrying about it getting smashed.

[1]
[http://www.kosagi.com/w/index.php?title=Novena_Main_Page%E2%...](http://www.kosagi.com/w/index.php?title=Novena_Main_Page%E2%80%8E)

[2] [http://www.element14.com/community/community/knode/single-
bo...](http://www.element14.com/community/community/knode/single-
board_computers/sabrelite)

Edit: looks like it's not for sale, but hackaday mentions they might if
there's enough interest.

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snarfy
Why would anyone clone the Raspberry Pi's form factor? Why would you ever want
connectors on all four sides?

Of all the things to clone on the Raspberry Pi, the form factor shouldn't be
one of them.

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zx2c4
Anyone know any single board computers with multiple gigabit ethernet ports?
My UBNT EdgeRouter Lite with Gentoo on it just isn't powerful enough anymore.

