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by Jim Manley
Sat Mar 10, 2012 7:57 am
Forum: Staffroom, classroom and projects
Topic: Requirements specification for RPi case
Replies: 29
Views: 7202

Re: Requirements specification for RPi case

<t>I like your list, Mike, although I would prefer robust clips over screws - we want to encourage kids to open it up, and having to find a screwdriver, dropping the screw(s)/screwdriver across live pins that shouldn't be shorted, and other Murphy events all add up to a negative experience.<br/> <br...
by Jim Manley
Sat Mar 10, 2012 7:24 am
Forum: General programming discussion
Topic: Best first language choice
Replies: 140
Views: 32437

Re: Best first language choice

<t>John Beetem said: <br/> <br/> <br/> Jim Manley said: <br/> <br/> <br/> OK, I can see how some parents might not find the subject of a beer-drinking song appropriate for their kids ...<br/> <br/> <br/> So just use the computer science version of the song <br/> <br/> <br/> 99 little bugs in the cod...
by Jim Manley
Sat Mar 10, 2012 7:14 am
Forum: HATs and other add-ons
Topic: Gertboard
Replies: 258
Views: 105877

Re: Gertboard

<t>The board is just fantastic, that is really what I think.  Oh, by the way, which one's Pink?<br/> <br/> GertBoard_count++; // <br/> <br/> This really is a boffo job, Gert.  If we can drag enough of us old hardware-enabled farts at least to local RasPi SIG/UG meet-'n-greets, we can definitely gene...
by Jim Manley
Sat Mar 10, 2012 5:26 am
Forum: Staffroom, classroom and projects
Topic: Linux From Scratch
Replies: 7
Views: 16678

Re: Linux From Scratch

<t>If you're not already aware, the R-Pi GPU actually boots directly from the SD card and a bootloader sets up and kicks off the ARM CPU, where things become more typical for any ARM development.  Rumor has it that the GNU gcc and related tools are not included in the initial Fedora port (not sure a...
by Jim Manley
Sat Mar 10, 2012 5:04 am
Forum: Staffroom, classroom and projects
Topic: ARM Assembly / Operating System
Replies: 48
Views: 17131

Re: ARM Assembly / Operating System

<t>If you're not already aware, the R-Pi boots directly from the SD card via the GPU ROM, which loads and executes a bootloader that then brings up the ARM CPU in what eventually becomes a more-or-less standard ARM startup (think of the BCM2835 as a screaming 26 GFLOPS floating-point/matrix-multiply...
by Jim Manley
Fri Mar 09, 2012 7:26 pm
Forum: General programming discussion
Topic: Best first language choice
Replies: 140
Views: 32437

Re: Best first language choice

<r>Of course, there is no one "best" language, or "best" first language – the former depends on the task to be performed and the platforms and environments available, and the latter depends on the student, and the platforms and environments available.<br/> <br/> I would suggest that kids be pointed ...
by Jim Manley
Fri Mar 09, 2012 5:21 pm
Forum: Other projects
Topic: MagPi – Raspberry Pi Magazine
Replies: 262
Views: 49682

Re: MagPi – Raspberry Pi Magazine

<r>MagPi looks nice.  I guess it will look even better with a table of contents which, of course, implies that there is some content!  I can help fill the void, and we need to be careful to structure it with kids in mind to make sure we don"t talk way over their heads, and yet, provide enough detail...
by Jim Manley
Thu Mar 08, 2012 8:48 am
Forum: General discussion
Topic: Power supply needed whith powered hub?
Replies: 8
Views: 1536

Re: Power supply needed whith powered hub?

<t>Abishur said: <br/> <br/> <br/> The r-pi has a 140 mA fuse on the USB ports so it won't be able to draw more than 140 mA.  If you're only attaching a keyboard/mouse/wifi adapter you should be just fine.  If you're attaching more or a hard drive, you won't be able to power all the devices from the...
by Jim Manley
Wed Mar 07, 2012 10:05 pm
Forum: General discussion
Topic: STICKY: Introduce yourself!
Replies: 3564
Views: 129409

Re: Introduce yourself!

<t>I'm Jim Manley and I'm a Raspaholic ... oh, wait, wrong group! <br/> <br/> Well, the cat's out of the bag, already - I've been excitedly following the R-Pi development since the demos of the early USB-HDMI stick prototype in May 2011 and was one of the 100,000+ victims ... I mean customers ... tr...
by Jim Manley
Tue Mar 06, 2012 4:20 am
Forum: Other projects
Topic: VirtualBox simulator and emulator - now with added Cow
Replies: 93
Views: 212520

Re: VirtualBox simulator and emulator - now with added Cow

<t>OK, copied the .ova archive over to an XP machine and (after upgrading VirtualBox to the current 4.1.8) it immediately opened the archive for import.  The import succeeded and the Ubuntu image booted right up.  I rebooted my original Windoze 7 machine and tried again and, voila, VirtualBox import...
by Jim Manley
Mon Mar 05, 2012 6:46 pm
Forum: Other projects
Topic: VirtualBox simulator and emulator - now with added Cow
Replies: 93
Views: 212520

Re: VirtualBox simulator and emulator - now with added Cow

<r>Sorry, yes, the zipped file contained the torrent link and it did point to the large shared .ova archive, which I did download, obviously, and VirtualBox seemed to think it was a valid archive at some level.  I do have some XP systems I can copy the archive to and try opening with VirtualBox, and...
by Jim Manley
Mon Mar 05, 2012 2:46 am
Forum: Other projects
Topic: Pi-sized monitors?
Replies: 6
Views: 3879

Re: Pi-sized monitors?

<t>These are fine to use as a display and audio player for an R-Pi.  However, note that most USB ports are limited to providing no more than 500 ma at 5V (per the USB spec), and those on non-computing devices often either don't provide any power, or may provide less than the 500 ma.  A bare-bones R-...
by Jim Manley
Mon Mar 05, 2012 2:29 am
Forum: Other projects
Topic: The AutoPlane Project
Replies: 40
Views: 32851

Re: The AutoPlane Project

<t>Someone else will eventually point this out, so, I might as well do it now.  If you're talking about an actual airplane that can carry one, or more people, the regulatory bureaucracy is going to ground you permanently, or at least for a very long time.  As it is, they have to currently close down...
by Jim Manley
Mon Mar 05, 2012 2:08 am
Forum: Other projects
Topic: CAN Interface
Replies: 103
Views: 103771

Re: CAN Interface

<t>I assumed the intended application was for basic vehicle monitoring, so, that's why I pointed out the very cheap diagnostic cables.  If the drivers exist (or can be built via simple recompile), that would probably keep the educationally-minded audience entertained for life.  Hooking up a $35 sing...
by Jim Manley
Mon Mar 05, 2012 1:42 am
Forum: Networking and servers
Topic: High availability webservice cluster
Replies: 21
Views: 13073

Re: High availability webservice cluster

<t>Since the R-Pi is for education first and foremost, this is a good idea for learning the concepts of a multi-processor architecture, but, the R-Pi's hardware configuration is overkill on a per-processor level in the real world, vs. the architecture of the HP designed-to-purpose product.  Processo...
by Jim Manley
Mon Mar 05, 2012 1:05 am
Forum: Other projects
Topic: Printable cases (using OHP film)
Replies: 18
Views: 13376

Re: Printable cases (using OHP film)

<t>tzj,<br/> <br/> This really is perfect - requires a minimum of materials, can be produced in large quantities very quickly, provides a sturdy, self-supporting structure that's stiff when folded up, supports the board via the connectors (assuming the fit is tight enough - I guess you'll find out a...
by Jim Manley
Mon Mar 05, 2012 12:34 am
Forum: Other projects
Topic: VirtualBox simulator and emulator - now with added Cow
Replies: 93
Views: 212520

Re: VirtualBox simulator and emulator - now with added Cow

<r><br/> When I try to launch the VirtualBox image, I get a "Cannot access the kernel driver" error.  The zip file seemed to extract fine to a .ova file, and VirtualBox lists it just fine, indicating it's a valid archive file (at least in the header?), but, perhaps something beyond the header got mu...
by Jim Manley
Sun Mar 04, 2012 6:31 pm
Forum: Other projects
Topic: CAN Interface
Replies: 103
Views: 103771

Re: CAN Interface

<r>It appears that CAN-USB interfaces start around $14 for the adapter cables used to connect a laptop to a vehicle's CAN bus:<br/> <br/> <URL url="http://www.google.com/search?q.....=0CI4BEK0E">http://www.google.com/search?q.....=0CI4BEK0E</URL><br/> <br/> Of course, the USB device drivers that com...
by Jim Manley
Sun Mar 04, 2012 11:31 am
Forum: Other projects
Topic: can you have any linux os on the raspberry pi
Replies: 6
Views: 2292

Re: can you have any linux os on the raspberry pi

<t>Ubuntu 9.04 (Jaunty) for ARM11v6 may partially work, but, the current version of Ubuntu is now at 11.10 and only supports ARM..v7 (Coretex) and higher, with 12.04 LTS currently in testing.  Ubuntu has no plans to provide support for ARM11v6, which is unfortunate.<br/> <br/> The versions of Linux ...
by Jim Manley
Sun Mar 04, 2012 9:47 am
Forum: Other projects
Topic: Car Computer?
Replies: 55
Views: 83564

Re: Car Computer?

<t>7D_Sniper said: <br/> <br/> <br/> Could the RPi be powered by 12 volts?<br/> <br/> In theory, the R-Pi can be powered from any 6 - 20 VDC source at 200 ma for the bare board, and up to 700ma recommended for maxed-out Ethernet and USB ports.  The 5 VDC micro-USB connector was decided late in the d...
by Jim Manley
Sun Mar 04, 2012 9:47 am
Forum: Other projects
Topic: Car Computer?
Replies: 55
Views: 83564

Re: Car Computer?

<t>7D_Sniper said: <br/> <br/> <br/> Could the RPi be powered by 12 volts?<br/> <br/> In theory, the R-Pi can be powered from any 6 - 20 VDC source at 200 ma for the bare board, and up to 700ma recommended for maxed-out Ethernet and USB ports.  The 5 VDC micro-USB connector was decided late in the d...
by Jim Manley
Sun Mar 04, 2012 9:35 am
Forum: Other projects
Topic: VirtualBox simulator and emulator - now with added Cow
Replies: 93
Views: 212520

Re: VirtualBox simulator and emulator - now with added Cow

<t>When I try to launch the VirtualBox image, I get a "Cannot access the kernel driver" error.  The zip file seemed to extract fine to a .ova file, and VirtualBox lists it just fine, indicating it's a valid archive file (at least in the header?), but, perhaps something beyond the header got munged?<...
by Jim Manley
Sat Feb 25, 2012 6:31 am
Forum: Other projects
Topic: Reuse commercial items with Rasberry
Replies: 2
Views: 1439

Re: Reuse commercial items with Rasberry

riggsre said:


Your english is much better than my... whatever that is.

Since he's from Belgium, that would be Flemish (similar to Dutch) and/or French, depending on where in Belgium his ancestors came from (closer to France or the Netherlands).

by Jim Manley
Sat Feb 25, 2012 3:51 am
Forum: Other projects
Topic: Pi laptop in a box
Replies: 24
Views: 10408

Re: Pi laptop in a box

<t>The R-Pi can accept 6 - 20 volts as input, although the production boards will be equipped with a micro-USB connector common to cell phone chargers.  The R-Pi only requires one watt which, at 5 volts, is 200 ma of current.  At least another 100 ma should be added for pass-through to a USB device ...
by Jim Manley
Fri Feb 24, 2012 5:24 pm
Forum: Other projects
Topic: Bare metal Raspberry Pi
Replies: 23
Views: 6743

Re: Bare metal Raspberry Pi

<r>As an educational opportunity, _this_ is one of the most important kinds of things that the R-Pi will enable budding geek kids to learn.  I'm a SillyCon Valley software engineer and volunteer senior docent at the Computer History Museum in Mountain View, CA (<URL url="http://www.ComputerHistory.o...

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