Category Archives: Technology

Really everything related to technology

Electronics, Linux

Kernels on those phones

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So Google says there could be 18 phones running Android by the end of this year. In Sweden we just days ago got HTC Magic, the first ever Android phone showing up here (tied to a ridiculous operator deal that makes me and lots of my friends not go that route). Then Palm shipped their Palm Pre just days ago, also based on Linux.

This has brought the interesting questions: how is the state of these kernel HTC Magicports in regards to the mainline Linux tree? They’re both using ARM cores (of course).

The ARM kernel maintainer Russell King himself is not impressed. Apparently Google hasn’t even tried to push their work upstream to the kernel in a long while. The tone in that discussion did make it sound as if they might be starting to work on this again now.

The Palm guys apparently haven’t even yet shown any code at all, but is said to be releasing their code within two weeks to opensource.palm.com.  They have not even tried to push their work upstream, so I figure they’re either not even going to bother or they are facing a rather steep uphill battle in the future.

Electronics, Rockbox

Lyre

I’ve previously blogged about the initiative to build an own open hardware platform that can run Rockbox fine, and just today I noticed their new site is up and alive at:

http://lyre.sourceforge.net/

The hardware has changed quite significantly since the last blog entry of mine, and they’re now using a LPC3130 from NXP instead of the Atmel they had before, and I believe they’ve also changed codec/DAC etc. Me knowingly, Rockbox does not yet run on this newly produced board.

Lyre PCB

I should probably also add that this board is of course still quite far from being portable and there’s no news or info anywhere on how or if you can actually get one of these yourself yet.

Electronics, Linux

Eeepc with Linux and Swedish 3g

This is a follow-up on my “getting the new toy” from a week or so ago. An Eee PC S101.

I didn’t like easypeasy on it. It seems that distro is more or less Ubuntu Netbook Remix (UNR) with a little EEE flavor applied. What’s not to like about it? They seem to think that because this is a netbook, normal UI guidelines no longer apply so therefore they’ve scrapped the ordinary main desktop (and its menu) concept and instead have a new full-screen “app launcher”. That’s not too shabby, but it comes with another idea that I can’t accept: they run all applications in full-screen mode by default.md400 And I couldn’t figure out how to alter that default.

Full-screen might be fine for some apps at some times, but then I’d like to explicitly ask for it instead of having to learn now to “unmaximize” each app (they’ve also removed/altered the window decorations so there are no standard three buttons on the upper right corner of the maximized windows). To top it off, it seemed that the latest easypeasy isn’t built with the latest ubuntu and thus it failed to connect with my 3g modem…

Instead I took the base version of eeebuntu for a spin and that is so much closer to what I want in a linux. It’s ‘base’ so it only comes with the bare minimum. It has no fancy alternative UI but relies on the traditional well-proven and by me liked X11 (gnome) desktop.

I inserted my Sony Ericsson MD400 USB 3g modem that I got from Telenor/Bredbandsbolaget and within a few seconds I was online. It couldn’t have been a much smoother ride.

I know people have expressed opinions that it’s a better idea to use laptops/netbooks with an internal 3g modem so that you don’t have to use any external devices so that it’ll be more slick and all. I think I was of that opinion as well until I got this usb thing in my hand. It’s basically just a tad larger than any ordinary USB memory stick (70 x 28 x 15 mm) so it’s really not much “in the way” or disturbing when inserted in a laptop and it comes with windows drivers on it (as it dual-serves as a usb mass-storage device as well). It makes it a perfect little device to move between different laptops. We have so far three laptops in our household and now I can get any of them onto 3g if I want to.

A little side-note on my eeebuntu install on the SD card: when I ran unetbootin I selected to install the “live/install” version on the hard drive (which of course is a SSD but anyway) to then install it on my SDHC card, but it simply wouldn’t work. I tried three times and every time it froze somewhere in the middle of the install. When I then re-ran unetbootin and made a boot usb stick, and then ran from there instead when I did the install, it worked perfectly…

Electronics, Technology

More HD sound

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Proving my point from before that everything wants to be “HD” these days, I read the Zune HD specs that come out recently and in that I found out that it claims to support HD radio. Amusingly enough, it does not claim mp3hd support which probably would’ve made the buzzword bingo crowds go wild. We can always hope for the next model! 🙂

So what is HD radio? The site says:

Instead of sending out one analog signal, stations send out a bundled signal – both analog and digital. Because it is digital, textual data such as traffic, stock info and song titles can be sent out, as well.

From what I understand, pretty much the same way RDS is already done.

The technology is not even new. The site lists news items from 2006 and yet I’ve never heard of it before. They claim FM stations get “CD-quality sound” and (as I find pretty funny) AM stations get “FM-quality sound”. What is “CD-quality” in this context I wonder? I find no mention or details on what exact codecs or bitrates etc they use. Wikipedia’s page to the rescue: it says you get approximately 100-150 kbps of a lossy “proprietary iBiquity HDC codec” which claims to be able to provide “CD quality as low as 64 kbit/s”. Somehow I think that sounds a little too good to be true. According to wikipedia HD radio beats DAB in audio quality.

And to top it all of, the FAQ describes what the HD means:

It does not mean either hybrid digital or high definition, it is simply the branding language for this new technology.

Personally I’ll just rather go IP all the way and stream my music/radio/video over that. I think media or content-specific transfer mediums/concepts of this kind are technologies of the past. For this reason, I don’t think DAB+ will have much of a future either.

Linux, Network

Linux on eee s101

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I got myself a new toy the other day: an Eee PC S101 with 16GB SSD, an extra 32GB SDHC and 2GB ram.

Asus EEE PC S101There’s already a bazillion instructions on how to install and run Linux on your EEE PCs out there, but they all seemed to miss one (for me) crucial little detail:

In order to boot from the SD card, you need to press Escape when the bios start-up screen shows.

But now: to get the bios screen to show, you need some extra magic: you need to press F2 immediately at start-up to enter the bios setup screen and then you need to disable “boot booster” as otherwise it’ll skip the escape checking entirely!

Using this trick, I’ve now installed easypeasy on it and I’ll dual-boot with XP for a while since it came factory installed with that.

I’ve fallen for the commercials and also subscribed to 3g broadband now (you know the blatant lying “up to 7.2mbit” which never in reality can even come close even if I would be alone sitting on top of a base station) and I warmed up my toy and connection the other day (still running XP then) by working on curl code and made a few commits etc, while sitting on a wooden bench next to the field where my daughter was having her soccer practice.

In fact, SSHing to my primary servers and editing code with emacs or reading email with alpine turned out a much better experience than I anticipated as I’ve read about how terrible the roundtrip times can be over 3g. It actually didn’t feel a lot more different than my regular SSHing from home over wifi.

Technology, Web

The web shop timeout mystery

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Another one of the things in the modern world I’ve not yet understood:

why on earth do some web-based shops timeout your shopping and automatically clear you “shopping cart” if you just leave it around for a few hours/days? Why why why? What harm does it do them if I don’t hurry on to purchase?

I love being able to press ‘buy’ on lots of stuff (that then are added to the “cart”) and then ponder a few days if I want more stuff, if I selected the right models, alter a few things and similar. So when they time-out on me like this, it’s like a blow in the face and I need to start over again. It’s simply crazy that I have to backup my list of things to buy just in case they’ll flush me before I’m done!

Yes, I’m aware that some sites offer “save lists” etc if you’re registered and logged in and all, but I don’t want to have to do that.

I can imagine that at times things run out of stock or they even change the prices of merchandise that’s in my cart, but they could still solve that in other ways than just clearing everything.

Network

bittorrent vs HTTP

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A while ago I put together my document FTP vs HTTP that compares data transfers done using those two protocols. Similarities and differences.

Today I’m taking the next step in this little series and I offer you Bittorrent vs HTTP! This document discusses differences in areas such as:

  • Transfer Speed
  • Streaming
  • Uplink
  • Firewalls
  • Redundancy
  • Server Load
  • Encryption
  • Protocol Standards

As usual, I’m all ears for your valuable input and help on making it more accurate and more detailed than I manage to myself. Point out my mistakes, my weird use of words or whatever. Post a comment here or email me.

bittorrent vs http

cURL and libcurl, Linux, Mail, Network, Web

HTTP Status Report

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Mark Nottingham Mark Nottingham held a very interesting one hour talk on the status of HTTP and the work on HTTPbis on a QCon conference recently, and luckily for us HTTP geeks there’s this great video/presentation from that.

curl is mentioned at least twice in the slides, unfortunately it has a wrong fact on the second mention where it says curl uses “Pragma: no-cache” as it isn’t true anymore. It used to do that, but we’ve stopped doing it in curl since a while ago.

I’m a subscriber to the httpbis mailing list and a casual contributor, but nonetheless his summary and overview of the state was refreshing as I’ve not been able to keep up with all the details and I haven’t been tracking that working group from its start either.

Electronics, Rockbox

Rockbox gsoc2009

So finally it went public that this year Rockbox will be mentoring five students to reach their

individual goals and get their projects turned into realities.Gsoc 2009

The projects are new codecs, one is a new port, one is USB HID work and finally there’s this “make Rockbox an instrument” project.

Personally I’m admin for Rockbox gsoc effort for the third year, and this year I’m also co-mentoring a student (Robert Keevil) in his project to bring Rockbox to the Sansa View.

Let’s make this a great gsoc year!

Development, Electronics

USB converter woes

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USB to rs232 converters are just never sold properly advertising what chip’s inside and right now I want to know if this one UART I’m working with perhaps is not playing fine with my existing converter cable.

I have this XScale PXA270 on a toradex-colibriboard, and it has only one full featured RS232 (FFUART) and I’m about to move things over to the lesser featured BTUART.

A theory is that my current USB converter that is based on a “Prolific PL2303” doesn’t play nicely on the serial port that isn’t a full RS232.

So I ran off and bought a new cable. I grabbed the only model I found in my local Kjell & Company store – it’s quite different looking than my existing but there’s no hint anywhere on the package or inside of it that says what chipset that empowers it.

A quick drive back home (I’m working from home in this assignment), I plugged it in and I got to see this depressingly familiar dmesg output:

usbcore: registered new interface driver usbserial
usbserial: USB Serial support registered for generic
usbcore: registered new interface driver usbserial_generic
usbserial: USB Serial Driver core
usbserial: USB Serial support registered for pl2303
pl2303 2-2.4:1.0: pl2303 converter detected
usb 2-2.4: pl2303 converter now attached to ttyUSB0
usbcore: registered new interface driver pl2303
pl2303: Prolific PL2303 USB to serial adaptor driver

So what now? I hate how (my) computers these days don’t have serial ports while the entire embedded world still very much uses them. I think I’ll go searching in my closet to see if I can find an old crap computer with a serial port to try.

Another theory is that the port simply is broken hw-wise on the dev board but that’s harder to check for me right now.

Update: it was (as usual) only my stupidity that prevented this from working. If I switch it over to the correct baudrate the usb converter does fine. But before I found that out, I did find a computer with a serial port and I did see it working on that too…