Raspberry Pi Myths and Truths
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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.
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.
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...
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.
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.
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.
Add a cheap touch screen and suddenly applications that could only be done with high $$$ interfaces suddenly come downmarket where there is (I hope!) a hungrily waiting audience with their wallets open :-)
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.
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.
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.
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?
Right now everyone is in the process of creating materials to teach, getting the units out there and making sure teachers have the knowledge they need to get started.
Raspbian has made the browsing experience much better, but for a lot of teaching activities, making JS heavy sites work is not key.
The raison d'être of the Raspberry Pi is to be cheap enough that every school could have one for each student.
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.
The board is just a tool though. The real strength will be in creating a common experience and specific learning systems that teachers can use, share and improve and have a frame of reference that could work worldwide.
Some teachers are able to create a syllabus and teaching around programming already, but I'd say they're in the minority.
I think for real progress (in a language/as a programmer) you need a goal. A project.
The Pi is even hyped and interesting among people that already have their other 16 gadgets lying around and a couple VPS on top: It's so small and so inexpensive, that you can get really creative. Never learned to solder? Doesn't matter that much if the (capable) main part of your pet project costs about as much as two dozen Cheeseburgers from McDonalds.
Lots of people write software. People could just follow Learn Python the Hard Way - guided by a clueful teacher that could be a successful method - but the critical mass of a bunch of people doing cool things on a standard platform exposes exciting possibilities.
Imagine a 512byte / 1k graphics demo challenge. Everyone has the same hardware, so you don't have the cross-platform woes of modern intro challenges.
$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... [2]:http://www.raspberrypi.org/phpBB3/viewtopic.php?f=63&t=6...
>700mA on USB is not within the USB spec, and probably not accurate for current draw of a Pi.
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!
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... [3] http://elinux.org/R-Pi_Troubleshooting
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...
et al
"Generally speaking the model B raspberry PI was designed only for <100mA USB devices! That is because the PI's PSU was chosen with a power budget of 700mA in mind of which 200mA were assigned to the two USB ports, so the raspberry PI's (poly)fuses were designed only for <100mA devices, and typical 140mA polyfuses will have as much as 0.6 volt across them when drawing currents near the 100mA limit. As a consequence the USB ports are only directly suitable for "single current unit" USB devices which according to USB specifications are designed to work with just 4.4 Volt. Not only do non single current unit devices draw more current, (causing greater Voltage drops, and greater stress on the fuses) they also might require 4.75 Volt to work. Therefore any non single current unit devices will only work when powered from a powered hub."
Plugging in devices that take 150mA or more almost always cause problems. Sure these things aren't within the USB spec, but neither is my 2A iPad 3.
As for $25 vs. $35, oops. I pre-ordered months ago and had forgotten what I'd paid.
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.
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!
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
10 years ago I would have expected propaganda on terrible dangers of allowing children to use non MS software.
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.
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.