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by patrickhwood
Thu Apr 12, 2012 8:27 pm
Forum: General discussion
Topic: WiFi Adapter Support
Replies: 33
Views: 13179

Re: WiFi Adapter Support

<t>I've been using these USB devices with x86 and ARM linux for a couple of months now.  They're very nice and have good range for such a small device.  The drivers are standard in linux 3.x kernels (e.g., the beaglebone), but not 2.x kernels, at least up to 2.6.38, so I also had to build it on the ...
by patrickhwood
Sat Mar 24, 2012 5:36 am
Forum: General discussion
Topic: Power for USB external 2.5" harddisk
Replies: 25
Views: 6624

Re: Power for USB external 2.5" harddisk

<t>Oh, I should also note that depending on the DRAM part, if the rows are wider, read and write operations are usually spaced further apart to dissipate heat properly, so total current draw over a microsecond or so of memory activity probably won't be much different between the two parts.<br/> <br/...
by patrickhwood
Sat Mar 24, 2012 5:27 am
Forum: General discussion
Topic: Power for USB external 2.5" harddisk
Replies: 25
Views: 6624

Re: Power for USB external 2.5" harddisk

<t>Vindicator said: <br/> <br/> ...<br/> Also now that the model A has more memory that should mean it will consume more than the stated 300ma (maybe 400ma now) not sure.<br/> <br/> <br/> <br/> I would bet not: most DRAM current draw comes from the pin drivers and row activity.  Also, parts of memor...
by patrickhwood
Mon Feb 27, 2012 6:08 pm
Forum: General discussion
Topic: Linux Drivers
Replies: 7
Views: 2447

Re: Linux Drivers

<t>A lot of simpler devices (e.g., keyboards and mice) use standardized protocols over USB, so new drivers aren't necessary.  Wifi dongles are a different matter.  As new chipsets come out, new drivers are sometimes needed.  When buying something like this, I make sure that linux drivers are availab...
by patrickhwood
Tue Jan 17, 2012 12:32 am
Forum: General discussion
Topic: How to protect the filesystem without a save shutdown button?
Replies: 61
Views: 27620

Re: How to protect the filesystem without a save shutdown button?

<t>Yeah, most of the journaling file systems (like ext3) are very robust.  I have yet to see one trashed by a reset, unplug of a USB drive w/o unmounting, etc., whereas I've seen a few FAT32 file systems destroyed this way.  In fact, I have yet to see an ext3 file system ever need anything recovered...
by patrickhwood
Thu Jan 12, 2012 10:38 pm
Forum: Staffroom, classroom and projects
Topic: Teaching Programming - How will it all work?
Replies: 25
Views: 7870

Re: Teaching Programming - How will it all work?

<t>Of you could use the laptops to connect to the RPis.  If you have the ethernet-enabled RPis, you can use ssh or telnet and avoid using keyboards/monitors.  If the laptops have USB ports, there's probably a way to plug them into a usb hub along with the RPi and get them to talk (sounds like a prog...
by patrickhwood
Thu Jan 12, 2012 6:34 pm
Forum: Other projects
Topic: supercomputer
Replies: 6
Views: 3624

Re: supercomputer

<r>Actually, you should take a look at the FAWN (Fast Array of Wimpy Nodes) project at Carnegie Mellon University (<URL url="http://www.cs.cmu.edu/~fawnproj">http://www.cs.cmu.edu/~fawnproj</URL>).  Their first project was a cluster of 21 500 MHz embedded boards connected via ethernet over consumer ...
by patrickhwood
Thu Jan 12, 2012 6:10 pm
Forum: General discussion
Topic: Fragmentation
Replies: 34
Views: 8067

Re: Fragmentation

<t>Actually, you won't need to install anything to use FAT32 file systems, as this is very common across most linux systems, certainly all the ones that have been mentioned for the RPi.  You may or may not need to install packages for NTFS, though.<br/> <br/> Ext2fs, ext3 and ext4 actually refer to ...
by patrickhwood
Tue Jan 10, 2012 8:21 pm
Forum: Other projects
Topic: Raspberry Pi as HDMI Dongle
Replies: 10
Views: 9162

Re: Raspberry Pi as HDMI Dongle

That was announced a couple of days ago in the run up to CES.  It uses the same Broadcom SoC as the RPi.
by patrickhwood
Tue Jan 10, 2012 8:18 pm
Forum: General programming discussion
Topic: Best first language choice
Replies: 140
Views: 33944

Re: Best first language choice

<t>Unless you plan on doing a lot of web page development, I wouldn't start with JavaScript, as it requires more infrastructure to set up just to start writing simple programs.  I'd start with something that either has an integrated IDE or an interpreted console mode so you can focus on learning how...
by patrickhwood
Tue Jan 10, 2012 8:12 pm
Forum: Other projects
Topic: Raspberry Pi as HDMI Dongle
Replies: 10
Views: 9162

Re: Raspberry Pi as HDMI Dongle

WiMax?  I think you mean WiDi.
by patrickhwood
Fri Jan 06, 2012 7:15 pm
Forum: General discussion
Topic: Model A/B SD cross compatibility
Replies: 5
Views: 1860

Re: Model A/B SD cross compatibility

<t>My guess is that the same kernel will run on both boards.  This has certainly been the case with other ARM-based boards with multiple memory configurations.<br/> <br/> If that's not the case, then you can wait for a uboot port, then use that to chain load the kernel, passing appropriate arguments...
by patrickhwood
Fri Dec 09, 2011 10:32 pm
Forum: Other projects
Topic: WebOS
Replies: 12
Views: 2936

Re: WebOS

<t>WebOS, like Android, runs on a slightly customized linux kernel. The kernel mods for WebOS have always been available from Palm/HP; the WebOS UI framework has not -- until now.<br/> <br/> Of course, to run the UI framework, you'll need a touch screen or some way of emulating multitouch with a mou...
by patrickhwood
Fri Sep 02, 2011 3:44 am
Forum: Other projects
Topic: Porting programs from x86 to ARM
Replies: 8
Views: 9045

Re: Porting programs from x86 to ARM

<r>Quote from Svartalf on September 1, 2011, 05:18<br/> Quote from patrickhwood on September 1, 2011, 01:13<br/> Well then, let's not forget endian-ness and sizeof(long), as long as we're talking portability (at least sizeof(int) hasn't been 2 for a long time on anything useful).<br/> <br/> In the c...
by patrickhwood
Thu Sep 01, 2011 3:38 am
Forum: General discussion
Topic: FAT32 for SDCard and Patent Threat
Replies: 18
Views: 5864

Re: FAT32 for SDCard and Patent Threat

<t>Quote from hajj_3 on August 28, 2011, 11:09<br/> when do the FAT32 and NTFS patents end, isn't there a 14yr limit to patents or something then they become invalid?<br/> Used to be 17 years from the time of issue; now it's 20 years from the time of filing (minus any delays in the patent office sit...
by patrickhwood
Thu Sep 01, 2011 3:25 am
Forum: General discussion
Topic: Additional RAM from USB?
Replies: 30
Views: 8754

Re: Additional RAM from USB?

<t>Hmmm, let's do a little math:<br/> <br/> For a 1GB swap partition, if we assume 100% write usage at 10MB/sec for one year, we get just over 300K GB of data, or ~300K write cycles. This is in the range (100k to 1m erase cycles) for most current flash devices. Now note that this assumes your system...
by patrickhwood
Thu Sep 01, 2011 1:16 am
Forum: Other projects
Topic: Router with integrated Raspberry Pi.
Replies: 45
Views: 12361

Re: Router with integrated Raspberry Pi.

<r>You should be able to get most of the code you need from the dd-wrt CFE, which is based on this:<br/> <br/> <URL url="http://www.linux-mips.org/wiki.....nvironment">http://www.linux-mips.org/wiki.....nvironment</URL><br/> <br/> See also: <URL url="http://www.dd-wrt.com/phpBB2/v.....hp?t=25971">ht...
by patrickhwood
Thu Sep 01, 2011 1:01 am
Forum: Other projects
Topic: Assembly Optimization
Replies: 8
Views: 2774

Re: Assembly Optimization

<t>The problem with the GPU being closed source is that there are many problems that are not display related that are handled by GPU hardware better than a general-purpose CPU like the ARM. You only have to look at CUDA and OpenCL for some examples of this. Similarly, lots of "media accelerators" no...
by patrickhwood
Thu Sep 01, 2011 12:13 am
Forum: Other projects
Topic: Porting programs from x86 to ARM
Replies: 8
Views: 9045

Re: Porting programs from x86 to ARM

Well then, let's not forget endian-ness and sizeof(long), as long as we're talking portability (at least sizeof(int) hasn't been 2 for a long time on anything useful).
by patrickhwood
Thu Sep 01, 2011 12:04 am
Forum: Other projects
Topic: Router with integrated Raspberry Pi.
Replies: 45
Views: 12361

Re: Router with integrated Raspberry Pi.

<t>Quote from Lob0426 on August 28, 2011, 18:43<br/> OK time for a little of the theoretical here. If you could replace the routers FLASH with DRAM, my theory is that you could use the RasPi to write to DRAM each time the router boots. You could then boot it with an image of client mode or a Site Su...
by patrickhwood
Wed Aug 31, 2011 11:44 pm
Forum: Other projects
Topic: Raspberry Pi + arduino + opencv
Replies: 14
Views: 6586

Re: Raspberry Pi + arduino + opencv

<t>It's unclear whether a 700MHz ARM can run the OpenCV code fast enough for what you want to do. Most of this code is not optimized for any sort of GPU, even if you had access to the low level APIs for programming the Broadcom's GPU. Does anyone know whether there's any sort of SIMD support on the ...
by patrickhwood
Wed Aug 31, 2011 11:33 pm
Forum: Other projects
Topic: File and/or media server
Replies: 75
Views: 20442

Re: File and/or media server

And back to the original idea -- what about a local NAS to cloud server? Something that talks to box.net storage or amazon S3 and shares that locally over samba?
by patrickhwood
Wed Aug 31, 2011 11:32 pm
Forum: Other projects
Topic: File and/or media server
Replies: 75
Views: 20442

Re: File and/or media server

<t>We run a commercial RAID5 system at our office for network storage (Samba & NFS). There's a hot spare in the box, and if a disk dies, it emails the admin to make sure we replace it so we still have a hot spare. It'll prompt on a new drive that's too small as a hot spare, either letting us put...
by patrickhwood
Wed Aug 31, 2011 11:17 pm
Forum: General discussion
Topic: Sonic screwdriver
Replies: 10
Views: 1863

Re: Sonic screwdriver

How about an original series communicator -- incoming message sound effects at random times and random comm clips from the show when you open it? All you'd need is a small speaker hooked up to the audio out and a connector between the flip-top and one of the switches.
by patrickhwood
Wed Aug 31, 2011 10:58 pm
Forum: Other projects
Topic: Firewall/DHCP aka router (Difficulty: Novice->Moderate)
Replies: 46
Views: 10118

Re: Firewall/DHCP aka router (Difficulty: Novice->Moderate)

My guess is that he wants to use a separate dongle to do the firewall/dhcp so it can be used with any router/AP, rather than attempting to find a dd-wrt port for every box in the field (not possible, of course).

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