
Raspberry Pi Myths and Truths - shawndumas
http://www.hanselman.com/blog/Top10RaspberryPiMythsAndTruths.aspx
======
4ad
The comments in this thread kind of miss what I perceive to be the main point
of Raspberry Pi. The great thing about Raspberry Pi is not that's it's a cheap
enough _PC_ that you can run Python on, it's that it's a cheap device that has
_GPIO pins_ and video.

There are significantly cheaper ARM boards than the Raspberry Pi, but to my
knowledge none that have video output, or at least reasonably fast video
output. Tell the children (or potentially interested adults that have only
done software, never hardware) that they need to learn how to use a terminal
connected through a serial port, or that they need to learn about cross
compiling and other things and instantly the barrier of entry is huge. Tell
them they can't have graphics, only a teletype and nobody will care. Let them
have a simple thing they can plug a display and a keyboard into and _program
the I/O pins live_ while displaying graphical stuff you can see and relate to,
now that's something!

Look at Arduino, an expensive and vastly underpowered device, in many ways
unsuitable for the task people use it for, but very, very successful because
people don't have to deal with all the boring and idiosyncratic low level
setup stuff.

~~~
bandy
I keep watching, but all of the other ARM boards cost more than the Rπ –
usually greater than 3x the cost of the RπB. You can occasionally find an
Arduino for less than what the RπB will run you, and while it has the GPIO, it
doesn't have nearly the crunch the Rπ gets you.

Mine will be running some network testing software, driving a small handful of
devices – doing the work a small laptop was doing before, but with a better
power budget and in a much smaller form-factor. I don't need a display while
it's running - it's going to sit there and collect data for me until I command
it to shut down, at which point, I'll remove the SD, grab the data, and
process it a bit on a more capable box, although it's conceivable that I could
do it all on the Rπ itself.

~~~
bigiain
A bunch of us at Robots & Dinosaurs (a HackerSpace in Sydney) have been
playing with the TP Link WR-703N wireless routers* reflashing them with
OpenWRT - they're available from Deal Extreme or eBay for under $25 - it's got
no video, but it includes ethernet and onboard wifi. One of the guys has a
stackable "daugherboard" which breaks-out/adds a USB hub, FTDI/GPIO/JTAG and
two serial ports: <http://www.kean.com.au/oshw/WR703N/>

It's not as high powered as a RaspberryPi though, only a 400MHz cpu and 32M
ram (+4M flash) - they're useful little machines, but the onboard video on the
Pi kinda puts them in a different class. On the other hand, a Pi with
ethernet/wifi/powersupply costs several times what a TP-W703N costs...

* <http://wiki.openwrt.org/toh/tp-link/tl-wr703n>

~~~
bandy
Several times? $35USD list price, and approximately $49USD delivered
(tax/shipping).

I could do my project with dd-wrt/openwrt, but I'd be storage-limited. A day's
worth of data is in the hundreds of megabytes range, uncompressed.

Your WR-703N plus a daughterboard would make an OK basis for a NAS.

~~~
semanticist
A Raspberry Pi also requires a PSU, an SD card, and a case. By the time you
add those in, you've probably doubled your cost, at least.

~~~
bandy
Powered off of mini-USB (I have extra chargers laying about), SD cards are
cheap cheap cheap (I also have a selection on-hand), and a case can be made
out of LEGO bricks (again…).

You forgot to add-on "keyboard, mouse, and monitor". Again, these are things
that people usually have.

For the dev cards mentioned up-thread, you'd have to have some sort of
programming dongle, which more than doubles their cost, as well as get your
hands on the right magic toolchain.

~~~
bigiain
All true - still means that bare minimum, a Pi (delivered) is double the price
of a W703N (delivered).

If you need add any/all of: wifi, power supply, SDcard, enclosure - to the Pi
for your project, then I think "a few times the price" is a reasonable
description. Not everybody will have "spares" of those "on hand", and if your
project involves building more than one of whatever _, then you can't rely on
"on hand" extras.

On the other hand, if you don't need wifi and you do need video out, then the
Pi is an obvious choice.

_ my project for the TL-W703N is a Tahoe-LAFS server/storage appliance - the
router and a 1 or 2TB USB harddrive - if I could put 10 or 12 of them together
and distribute them amongst friends, just a harddrive sized package they need
to plug into the wall and allow on their wifi (or wired) network, in return
everyone gets several hundred Gig of "private cloud storage" with baked-in
encryption and distributed storage reliability.

------
andy_herbert
'It is great for learning to code '

When the machine was first pitched it was as a spiritual successor to the BBC
Micro computer - to inspire and create a generation of bedroom programmers.

Compared to the home computers of the 80s, the Raspberry Pi isn't as simple to
use, you have to jump through quite a few hoops to get to a point where you
can start to code in Python and in my opinion is sufficiently difficult enough
to deter the lay person; a little bit more complicated than turning on a
machine and getting a BASIC interpreter you can start typing commands into.

In my experience most of the Raspberry Pi community has been more interested
in porting emulators and media players, rather than nurturing basic skills in
computing for kids. I believe the world still needs a machine to get kids more
interested in computer science and away from the spreadsheets and word
processors, but I don't think this is the machine to do it.

~~~
ivarkotnik
The current RasPi community is not the community it was really intended for.
It's primary audience is kids and youngsters and allowing them to get a
feeling for a computer.

And kids today are way smarter than I was at their age. They catch on very
quickly and their curiosity as well as thirst to learn allows them to quickly
adapt the RasPi to their wishes.

~~~
slurgfest
Anyone who thinks that it was easy for kids to program those old computers
probably doesn't remember looking through thick manuals of memory addresses,
which would lead me to question how much they really did.

~~~
shanselman
LOL, totally. I remember entering in the escape codes for an Epson FX-80 dot
matrix printer because there was no such thing is a printer driver. Just
copied it from the back of the manual. Took a weekend.

------
rodh257
I think the tech media built these devices up a bit too much to the general
consumer public. They are really a learning tool that you can tinker with, not
a 'cheap pc' like they were built up to be. So many people got theirs after
the pre-order wait and immediately complained about the performance. Think of
them as a beefed up Arduino style device and you'll love it, think of it as a
cheap computer for consumer use and you'll obviously be unhappy.

~~~
gravitronic
It's not that simple. The device has the potential to be an easy to use pc for
the general public, but the community hasn't finished the software yet. The
media reported the potential not the reality (there isn't a large quantity and
it's just a little debian box).

As for the people who have one (like me) a large portion of the complaints
aren't about the total performance capability, but it's the stability.. mine
crashes all the time. There's some talk about fixing a bug in the USB driver
that'll solve the issue (everything hangs up for 2-4 minutes every 20 minutes
on average) but until that's finished it's rather unusable.

------
jiggy2011
I think the pi will have some problems being successful with it's target
market (kids who want to learn to code) if it's web browsing experience is dog
slow.

Does anybody know if it is being actively used in education anywhere or are
the users mostly geeks using it to run an apache server from their RC
helicopters?

~~~
astine
I dunno. Perhaps it hits just that sweet spot where Stackoverflow loads just
fine but Youtube is unbearably slow?

------
tshadwell
Can someone please explain to me why the Pi is good for those looking to learn
to code in python or scratch? Both are cross-platform, and both rely very
little on the OS they run in, at least at the basic level.

~~~
freehunter
The problem isn't what computer you run it on, the problem is having a
computer to run it on in the first place. There are still many schools and
many households without computers. The school I went to is still using Apple
IIe machines given to them in a grant decades ago.

The _raison d'être_ of the Raspberry Pi is to be cheap enough that every
school could have one for each student.

~~~
thejteam
Schools that can't afford enough computers also can't afford new monitors and
TVs with HDMI connections, which if I recall the raspberry pi requires.

~~~
jiggy2011
The Pi will work with svideo IIRC so you can plug it into an old TV. How well
the window manager will work at that resolution on the other hand..

~~~
peteri
Actually the Window Manager seems to be OK (if a bit blurry). There may be
problems with games going full screen for example open-invaders is a few
pixels short on my PAL TV so only half of the score characters are visible,
dunno if I should fix the display settings or fix the program.

Biggest problem I can see is that Midori as a browser seems to struggle on
things like Google+ Photos (This may just be an out of memory and hitting swap
problem, I've not investigated)

I haven't thought about what I'm going to do with mine yet (it was a gift from
my father). It does come with Squeak so if thats useable on a CRT I may give
that another go.

~~~
nfriedly
I believe there was a menu option to handle TV's overscan in the text-only
interface that appears the first time you power it up with Raspbian installed.

------
bradfa
When that's your title and your first paragraph has at least 2 errors in it,
how likely am I to believe what you say in the rest of the piece?

$25 does not get you Ethernet on a Pi.[1] >700mA on USB is not within the USB
spec, and probably not accurate for current draw of a Pi.[2]

[1]:[http://www.newark.com/jsp/search/productdetail.jsp?id=83T194...](http://www.newark.com/jsp/search/productdetail.jsp?id=83T1943&Ntt=83T1943)
[2]:[http://www.raspberrypi.org/phpBB3/viewtopic.php?f=63&t=6...](http://www.raspberrypi.org/phpBB3/viewtopic.php?f=63&t=6050&start=50)

~~~
michaelt

      >700mA on USB is not within the USB spec, and probably not accurate for current draw of a Pi.
    

The raspberry pi quickstart guide at <http://www.raspberrypi.org/quick-start-
guide> says to use a power supply capable of supplying 700 mA.

The page you link to says the RPi can consume 435-465mA just from CPU and
Ethernet, meaning only ~250 mA of the RPi's 700mA power budget remains to
power the two USB host ports. Just plug in a USB device that draws more than
250mA (like a second RPi) and the claim of consuming more than 700 mA will be
proved correct!

~~~
gravitronic
If you plug a USB device that consumes more than 100mA into the pi it will
likely not power the usb device without a powered hub in between.

~~~
michaelt
I've checked the RPi schematic [1] and it each of the USB ports protected by a
miniSMDC014 rated for 140 milliamps [2] (and taking 150ms to trip at 1.5 A)

With two usb devices drawing 140 mA, a total of 280 mA would be consumed,
thereby narrowly exceeding the 700mA power budget. Fuses are also typically
quite imprecise for obvious reasons - they rely on current heating up metal
that melts and breaks the circuit, and you don't want it borderline molten
under normal operating conditions! So you may well be able to draw 250 mA per
port without the fuses triggering.

You'll note the Raspberry Pi wiki [3] has a bunch of bug reports like
"Ethernet connection is lost when a USB device is plugged in" attributed to
inadequate power supply current.

[1] <http://www.raspberrypi.org/archives/1090> [2]
[http://datasheet.octopart.com/MINISMDC014F-2-Tyco-
Electronic...](http://datasheet.octopart.com/MINISMDC014F-2-Tyco-Electronics-
datasheet-58412.pdf) [3] <http://elinux.org/R-Pi_Troubleshooting>

~~~
gravitronic
So, I've got one and am experiencing similar issues.. I believe that right now
the "power supply" issue had been used as a blanket response to ethernet/usb
issues until people were seeing that problem with an oscilloscope on their
power supply and no power supply issues.

What seems to be the common conclusion is that it's a bug in the DWC OTG USB
driver/firmware:

[http://www.raspberrypi.org/phpBB3/viewtopic.php?t=9470&p...](http://www.raspberrypi.org/phpBB3/viewtopic.php?t=9470&p=128799)

et al

------
Florin_Andrei
I actually like that browsing is kinda slow. One of my kids can code a little
bit in Python, the fact that browsing is suboptimal helps him stay focused on
coding. :)

I don't think it draws 700 mA except when it's really crunching CPU cycles.

The distro name is unfortunate. They should just call it "Raspian", it's a lot
less tongue-tying.

~~~
shanselman
It draws about 350-400 mA when it's running but then another 100 mA per USB
port in use.

------
lifeguard
I suspect that less than 1% of the people who comment on Raspberry Pi threads
posses one. I sure don't.

Please reply to my comment with your home country and when you _received_ your
device if you have one. I had trouble ordering and gave up.

Thank you!

~~~
jfoucher
I received mine in may if memory serves and I currently have it hooked up to a
LCD monitor. We use it to watch movies, as a samba server and my 3 year old is
learning to type on the command line even though he can't even read yet

We also use it to play music through mpd which is great because it can be
controlled from any device in the house All in all probably the best 35€ I
ever spent

------
jiggy2011
Nice to see objective & balanced views on the raspberry pi from a MS employee.

10 years ago I would have expected propaganda on terrible dangers of allowing
children to use non MS software.

~~~
shanselman
Thanks!

Working for Microsoft doesn't change my opinion on reality, though. I try to
stay outside the Redmond Reality Distortion Field.

That said, I'm consistently surprised/impressed that every blog post I write
that gets on HN includes a notification that I'm a Microsoft employee.

We are not nearly as organized as we'd need to be to be as evil as folks think
we are.

Again, thanks.

------
mtgx
Looking forward to when they release a Cortex A7 (dual core maybe?) version
that can run Ubuntu.

~~~
exDM69
I have a "desktop pc" that has a dual core Arm Cortex A7 at 1 GHz, 1 GiB of
memory and a GPU that will tear the RPi to shreds. And it runs almost vanilla
Ubuntu.

But it's not usable for a desktop PC. The desktop is slow and sluggish because
it's not properly hw accelerated. You can't use it for web browsing because
all the modern web sites are too heavy.

The low-cost ARM system on chips can run Android fluently only because so much
effort has been put into making Android run on them. This work is done by the
SoC vendors and is generally not upstreamed.

