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A smart BeagleBrick March 29, 2009

Posted by Florian in Devices, GPE, Linux, OpenEmbedded.
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Some time ago I wrote some lines about the nice combination of projected human interfaces such like the TI PICO projector for visual output and the ‘laser keyboard’ for input. The innovation you can gain from such a combination is a device whose interfaces dimensions can can differ from the dimension of the device quite a lot. After playing around and having an interesting time watching people using these technologies (e.g. at FOSDEM) I finally manged to create a device study combining the components into a single case. It turned out to be more complicated than I thought and the way to a ‘production ready’ device would involve a lot of research and improvement.The main idea was to have something you can touch and try if it can be useful.

But let’s take a look at it first – for now its just a kind of brick with a BeagleBoard and some more components inside.

"The Device" in action

"The Device" in action

From a technical point of view the contruction is quite simple – its just a collection of easy to get components:

  • TI BeagleBoard (Rev. B4 in this case)
  • Celluon CL850 “Laser Keyboard”
  • A tiny USB hub
  • TI PICO projector
  • Some custom USB cables
  • Huawei UMTS modem
  • One Bopla BOS 800 case
  • A small RS-MMC card for the root filesystem

The batteries didn’t fit into the case – the same problem like my GSM evaluation platform I intended to use for connectivity. Instead of this I had to use the Huawei modem but lost an easy to use audio part (I still would like to see these interfaces in some kind of smartphone) and the charger for Li-Ion batteries. The USB connected UMTS modem is advertized to have audio capabilities but there is no Linux support for this feature yet. Another component that caused some headaches is the HDMI cable for the PICO projector: It is thick and its big plugs waste a lot of space in the small case.

I removed the cases of USB hub and keyboard to make them fit into the case. From the BeagleBoard I had to remove the S-Video connector in order to reduce its height.

The current software is way less spectacular than you might think. Its a simple Ångström distribution GPE image built with OpenEmbedded. I had to replace Xorg with Kdrive in order to get the Xrandr extensions working and added some more software for testing such as an additional browser. This is not really the software you wold expect for a modern smart phone but its a good environment to test an uncommon mobile computer.

So what did I find out in the initial tests?

  • It looks very very geek!
  • Its useful to some extend but you need an even surface.
  • The mechanical design needs improvement. This ‘brick’ case is not really flexible and even a better arrangement of components (e.g. projector and keyboard side by side) would save a lot of space on the table.
  • It would be necessary to have a different lense for the projector: You want a wide angle lens to get a large projection area in a short distance drom the device. As you can see in the image the desk space you need is quite high but the image is still small.
  • The power consumption of the projector is a major problem. It is hard to power with batteries and in a plastic case it gets very hot.
  • Someone needs to come up with a clever holder for a sheet of paper to make it a useful screen. Suggestions welcome!
  • If I have the chance to do so I would like to try an improved prototype with a small secondary display, batteries and a keypad.
Typing on the table

Typing on the table

A device I could imagine would be a kind of a stand for a smartphone with built-in projector module. The next generation of projector modules should be small enough for this and comsule less power. The stand would allow the phone to stand upright on the table and provide the keyboard functionality. The advantage of this solution would be that you would not have to carry around the keyboard engine all the time. And because of the orientation of the phone you can get larger ‘screens’ if the projector is in the top end of the phones case. Maybe I should sketch this for the next blog entry… :)

Have a nice time!

Some good News March 14, 2009

Posted by Florian in LinuxToGo, Maemo.
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While the ongoing financial and ecomomic crisis seems to be the most popular topic for months now I try to make this blog a little more positive – some pice of contrast.

I has been a little bit quiet around LinuxToGo for quite a while. We didn’t manage to do more than the absolutely vital administrative tasks and the machine suffered badly from the high load. But there are some lights on the horizon: First I seem to have a little bit of time to work on it again – I managed to sort out the worst I/O bottleneck caused by having all I/O load on a single disk. Thanks to Jay7 for the hints! I wrote a few lines about the server status and some statistics here.

The second is that LinuxToGo has gained new sponsor: Bytemark Hosting sponsors a virtual server for us. Now we finally have the chance to distribute the load among two devices. Many thanks to Nick Thomas (lupine_85) for the idea and approaching us and his boss Matthew Bloch!

There are quite some good news in the Maemo world as well. First is that the Maemo Community Council elections have started – active community members have the chance to elect the council till the end of March 19th. Mer, the community driven distribution project for Nokia Internet Tablets and some more devices seems to evolve more and more – there is a quite interesting article about it at LWN.net.

The new Mameo 5 SDK Alpha release runs on BeagleBoard now too – Juha wrote a blog entry about this in the Maemo DT group blog.

While we are on this topic already… the BeagleBoard has gained an interesting companion: The Leopard expansion board which comes with a camera and ethernet. I do not know much about it yet, but it is based on the TI DaVinci DM355. I’ll try to find out more and update the information here.

The last thing I’d like to mention is a little bit offtopic… I found this interesting proof for engineering beeing a kind of art while repairing the amplifier in my living room:

Creative, isn’t it?

I hope you enjoyed this tiny pile of good news :-)

Have a nice time…

The ‘other’ BeagleBoard March 8, 2009

Posted by Florian in Devices, Linux, Maemo.

I visited the Embedded World fair in Nürnberg on Wednesday this week together with some colleagues. Like always on events like this I stumble upon nice devices with Linux support… in fact embedded hardware like development platforms and devices for industrial use or consumer network stuff without running Linux seems to become uncommon. Just a few years back hackers had to search hard for useful devices or invest a lot of time reverse engineering consumer hardware. Unluckily cellphones are still problematic – even the linux ones are usually locked down so that they are not useful for developers.

But let’s stay with the ‘good’ ones: Karo Electronics showed a new low cost DIMM sized embedded module based on a 400MHz ARM9 CPU (The datasheet mentions Freescale, but lacks the name the chip.) A friend bought a similar one (a TX27) which came with full Linux kernel sources.

A real suprise was the booth of EBV: They build and sell their own BeagleBoard called EBVBeagle.

EBVBeagle (image source: EBV)

EBVBeagle (image source: EBV)

Its actually a BeagleBoard revision C2 with green PCB boxed with some useful accessories. It comes as a quite complete starter kit with AC adapter, USB to Ethernet adapter, MMC card, USB hub and some cables. The official press release can be found here. They claim (but not gurantee) to be able to deliver within two weeks. Looks like the only drawback is the minimum order value of 250 EUR which is – of course – more than the EBVBeagle kit.

Apropos Beagle Board – Maemo (which runs on the BeagleBoard too) has released some new bits. First  Maemo 5 alpha SDK is ready and released. This is pretty good for people using it on the Beagle Board because only the Maemo 5 SDKs support the OMAP3 SoC. For people who want to learn about Maemo development or development for Limux mobile devices in general there is a new Maemo Tutorial release. The Maemo Tutorial provides quite easy to understand and detailed information about Maemo platform and application development. It gives a lot of useful information about development for other Linux mobile device platforms as well.