Category Archives: Electronics

Consumer electronics, portables, whatever

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!

USB converter woes

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…

Fujifilm FinePix F100fd

Ok, I bought myself a Fujifilm FinePix F100fd camera the other day, as it fulfilled my requirements pretty good:

1. It’s compact, noticeably smaller than my previous Sony one.

2. While not a 3″ LCD it features a 2.7″ one, which is a tiny bit larger than my previous’ 2.5″.

3. Image Stabilizer. And in my test shots it seems to make a difference. I’ll admit I haven’t yet played a lot with it on and off, but especially when zooming it seems to do some good.

4. Good low-light images. Yes it does. I’ve so far seen it go down to ISO1600 on auto and while that isn’t the best pictures, using flash is certainly not a good way to achieve great pics either (in general).

5. It accepts SDHC cards. I put a 4GB one in to start with as it costs virtually nothing. My previous camera had 512MB so it’s still 8 times the size. Of course my Sony was 5 megapixels and this does 12 so it will of course produce larger image files.

Possibly I’ll try to make some comparison pictures with my old and my new cameras later on.

Rockbox coming along on Sansa v2s

There have been fierce activity in the dusty corners of the Rockbox project known as the SanDisk Sansa v2 hackers guild (no not really but I thought it sounded amusing) and this has so far resulted in early code like LCD drivers and NAND drivers on three new upcoming targets: The e200, Fuze and Clip.

There’s still work to do before the celebrations can start for real, but it’s still nice to see good progress.

Now run over and help out!

(picture by Bertrik Sikken)

Rockbox on the Onda VX747

Maurus Cuelenaere has been very busy lately with his work on porting Rockbox to the Onda VX747 player. This 3″ LCD 4GB/8GB flash player isn’t just touch screen and very ipod touch-looking, it is also equipped with the Ingenic Jz4732 chipset. This is particularly interesting because this baby boasts an XBurst processor, which has a MIPS core clocked at 240 to 400MHz.

In other words: this is the first MIPS-based target Rockbox is being made for. Maurus has custom code running on it, we have adjusted to build a MIPS toolchain and there seem to be a handful of other Chinese PMP players using this chip family so this is a good chance to get a whole bunch of new targets at once. Just join the fun!

Get all the latests news on development for this target and chipset family in this forum thread.

Onda VX747

Normally I would link to the company’s official page about a player but this image will take you to a gadget blog site, simply because I cannot find any official site or page for this device!

Bright Mobile Open Source Future

There have been so many open source initiatives for mobile phones in recent years it’s not even funny (limo, openmoko, Android to name some of the possibly biggest ones). The amount of actual phones on the market using one of them have been very very limited. Apparently there are some Motorola phones running Linux and you can get the Linux-based Nokia N800 tablets but they’re not even phones!

Obviously something has happened in the market though. Perhaps all those initiatives have pushed the big ones into thinking in more open source ways. The most interesting part of today’s news about Nokia buying the entire Symbian is their stated intension to open source it. (they’ve even already chosen the Eclipse Public License for it). It’ll be intereseting to see if there’s any interesting synergies coming up from Nokia’s previous purchase of Trolltech.

Of course, even Symbian has but a small fraction of the entire phone market as they sold 18.5 millions units in Q1 2008. IDC says 291 million phones were sold in the world during Q1 2008, which thus should position Symbian on roughly 6% of the phones that are sold today in the world!

I’m also curious if this will mean that Nokia will use Symbian on a larger scale on their own phones, as currently they seem to use Symbian only on a very small portion of their high-end phones. With Nokia owning the whole thing, they might see a bigger motivation to consolidate their own use of operating systems.

Portably Yours

Archos PlayerOne day in late 2001 I had a talk with my brother Björn and our mutual friend Linus about how their portable MP3 player was very cool but the software/firmware on it was rather limited and lame in many ways. (Correct, I didn’t own any portable music player at that time). As usual, we brought up the idea about being able to hack it yourself and oh how good couldn’t you make it then? Not very long afterwards, we had a mailing list setup for discussing how to reverse engineer and improve the Archos Player firmware. Personally, I had no device yet but it sounded like good fun so I subscribed and participated from the start. After a few months, I got myself an Archos Recorder to be able to get down on the metal too, and the Recorder was also slightly different and thus brought some more challenges to the team.

Archos Recorder

Archos RecorderThe Recorder was a step forwards since it provided better sound and a (gasp!) graphical LCD. Some of the first work I did in the Rockbox project was to work on the code for the LCD, to bring text to it using fonts and to provide line drawing routines etc. Keeping the entire screen in a separate “frame buffer” that is updated to the screen with a lcd_update() call was an early design decision that has stuck ever since.

We took the Rockbox a long way supporting more and more of the early SH-based Archos targets, including the V2s, the FM and the Ondio series. But eventually of course the models started to get hard to get and out of production. It was time to start looking into moving to other targets, and other targets would more or less force us into a world with software audio codecs!

I got my original Recorder stolen, but I had it replaced and put in a 80GB disk and it was much rejoicing.

iriver h140

iriver h140We did scan the market for targets that used somewhat standard components for which we could get specs and docs and we found the iriver h1x0 series and the work began. As usual we got plenty of help from everywhere and it didn’t take too long to show the nay-sayers that we could indeed transition Rockbox into the future with software codecs. We also took it to the h3x0 series with its color screen not that long after and my golly, didn’t an entirely new world of opportunities open? 40GB of disk was just about enough to hold most of my music collection.

iAudio X5

iAudio X5What’s the fun of Rockbox if I couldn’t follow along? I got the iAudio X5 early on in the porting effort and joined in and got my first color-screen target. Of course I didn’t like how the mere 20GB disk narrowed what music I was bringing with me, but hey some sacrifices had to be made for the greater good of advancing Rockbox! 😉

Rockbox was now booming and flourishing, coming to new targets all over and getting more and more developers involved.

Sansa E260

Sandisk Sansa e260A guy from SanDisk contacted us asking about a Rockbox port to their Sansa E200 series, and even though they sent me a bunch of targets etc they never provided any docs or actual help on the effort of porting Rockbox to these babies. Not even the figuring out the firmware format, as that was instead made by our own secret super-hero MrH.

Meizu M6

Time flies and soon enough (like in the late 2007) none of the targets Rockbox ran fine on were no longer being manufactured and started to get hard to get in shops all over the world. The eternal race to get Rockbox ported to a currently manufactured model of course just got more important.

It was almost two years since I got the Sansa e200 series from SanDisk and it was time to join in the efforts of bringing Rockbox to some Meizus. The amount of interested people and the existence of a (leaked) data sheet for the main SoC helped me settle for buying this.

Cowon D2

As I’ve already explained, I bought a D2 too at the same time I got the Meizu so that I could do comparison for people and just play around some extra.

Of course, my timing is dubious as I got my two new targets exactly at the same period in my life when I went back to work (almost) full-time from having been on paternity leave for six months. Together with my extra “admin duties” such as the euro devcon and gsoc 2008 happening, I really haven’t had much time to actually dive into low-level fiddling with the ports yet. Hopefully I soon get adjusted and get some time to really help out.

RF4CE goes 2.4GHz

I learned about the new consortium called RF4CE (Radio Frequency for Consumer Electronics) that seems to consist of a range of the consumer electronics giants (but oddly I cannot find any actual web site explaining any details on this gang) and they’re obviously working on a new remote control standard based on the IEEE 802.15.4 standard so hopefully we’ll soon see remote controls go to the 2.4GHz band and fight the growing number of devices there, to make remote controls more functional on wider ranges than the somewhat limited infrared thingies current devices use.

Oh, and of course that’ll force us to buy new “all-in-one” remote controls soonish… 🙂

Freescale press-release, Sony press-release

Twentyfour inches any good?

My 19″ (Acer) LCD screen at work died the other day. It started flickering a lot and when I tried to switch it off/on to see if the flickering would go away, it wouldn’t go back on again.

I got a lowly 1280×1024 screen to borrow until my new screen would arrive and I got to experience that using the panning screen thing of Kubuntu (my desktop would remain 1600×1200 since I preferred not to reboot or even shutdown my X) could easily get the mouse coordinates confused and then I had to hurry up to the upper left corner to “reset” the coordinates and then I could again click on the correct items on the screen…an lcd screen

Very well, I got a 24″ 240BW Philips. This being a widescreen thing (they’re really taking over the world, those widescreen versions) it prefers 1920×1200 resolution. My computer had one of them intel graphics chips (82Q963/Q965) on the board and dang, I got no good resolution no matter how I poked the xorg.conf file. After trying out 915resolution, I learned that the graphics card couldn’t in fact show the necessary resolution so I had to insert a card that can. I got a dreaded Nvidia and now I’m using the evil proprietary drivers to get DVI at this resolution…

But I must say that with my 19″ at 1600×1200 and my 20″ at home at the same resolution, bumping up the screen size yet another notch to 24″ makes me think 1920×1200 is kind of on the low side for such a huge screen. I did a quick check on my favourite tech stuff compare site ( but it seems there’s no screens with higher resolutions at this size?