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LinuxTag, GSoC and some progress… June 3, 2009

Posted by Florian in Devices, GPE, kernel concepts, Linux, Maemo, OpenEmbedded.
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Its time to make announcements… I should have done this earlier, but like always it takes me a while to find a free minute to write things down.

First is about OpenEmbedded: We will be present at LinuxTag from 24th to 27th of June in Berlin/Germany. I just hope they have a little bit more space for us at the Embedded Area compared to last year. We usually have a lot of interesting devices running OE built Linux we can show. I’m really looking forward to LinuxTag – I haven’t missed one for many years and its always a nice event with a good mixture of community members, business people and users.



Google Summer of Code is in progress for some weeks now and I’m in the great position to mentor a very interesting Maemo project… something I always wanted to see but noone found time to do it properly so far: Integrate the Maemo software framework into OpenEmbedded. The benefits are quite obvious – Maemo software will gain compatibility and quality by running on (and if necessary adapting to) various devices. Apart from the fact that Maemo is a pretty good open source framework attracting quite a lot of developers. This is something other devices can and should gain advantage from. Well rkirti made a pretty good description of the project which can be found here.

It would be pretty cool to see Maemo running on this nice device I received a few days ago…


Micro2440 running gpe-mini-browser2

Its a FriendlyARM Micro2440 from Watterott Electronic – this one is equipped with the 7 inch display which gives some more “freedom” to the applications :-) Apart from this the hardware is the same I described in my previous post.

The screen geometry would match the one used by all Maemo devices so far, so it would not mess up all the graphical user interfaces. But there is still some work to do till the boards become a really good development platform. We can build useful filesystem images for them but the installation is still split up into too many steps and the up to date kernels still lack proper support for the camera and the wifi module.

I have made a toolchain to build software for both these devices and the Topas910. Together with an updated install instruction it can be found here at labs.kernelconcepts.de.  Now I’m investigating ways to integrate the toolchains with IDEs in order to simplify application development for mobile and embedded devices.

Micro2440 with Ultimate++ demo application

Micro2440 with Ultimate++ demo application

Here the device runs one of the Ultimate++ demo applications built with its IDE and the GPE-flavour cross toolchain built with OpenEmbedded. A friendly colleague found out what needs to be done to use it for ARM targets… it still needs a little help since Ultimate++ doesn’t seem to have an idea about pkgconfig and I’m not really happy with the size of the resulting binaries. But more about IDEs later…

Have a good time… and see you in Berlin!

A friendly Development Board May 26, 2009

Posted by Florian in Devices, GPE, kernel concepts, Linux, OpenEmbedded.
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While we are at the topic ‘evaluation and development hardware’… here here a few lines about a similar piece of hardware. I promised to do something with a FriendlyARM board already – so I did. I choosed the Micro2440 because the board itself is very small and can be used for own design easily. The very similar Mini2440 has a lot of ports on board in contrast to the 2mm headers of the Micro2440. Both boards are available through local distributors in Europe and the US now so that its not necessary to place orders in China any more. Watterott Electronic was so kind to send me a Micro2440 board and the SDK baseboard for evaluation.

Micro2440 SDK

If you want to get started with embedded Linux the board might be exactly what you want: A 400MHz ARM9 based Samsung S3C2440A CPU which is pretty well supported by Linux. 64MB od RAM and the same amount of NAND flash and 2MB of NOR flash for a backup bootloader. The baseboard has the connectors for the serial ports, USB host and client, display, expansion and SD and adds an audio codec and an Ethernet chip. There are two variants available: One with a 3.5″ QVGA TFT (pictured) and one with a 7″ 800×480 TFT.  Both displays come with a touchscreen and in addition to this the board has a few buttons that can be used for a human interface. The whole SDK kit including Micro2440, SDK board, 3.5″ display cables and JTAG doesn’t cost more than 125 EUR incl. VAT which makes it even more appealing.

The ‘softer’ part of the SDK quite appealing too: The hardware is pretty well documented, even the schematics are available to the public. FriendlyARM released some demo images and Linux sources that are useful (but not perfect). The ‘Vivi’ bootloader used by the boards can be replaced with u-boot easily so that you get a 100% Open Source embedded development environment.

Thanks to the OpenMoko community the S3C is pretty well supported in Linux and u-boot. There is a public project providing up to date Linux, u-boot and QEmu supoort for these boards that can be found here. Like I usually do for a new piece of embedded or mobile hardware I used OpenEmbedded to built a GPE based filesystem image for it. Like you can see in the picture it works pretty well. For people interested in this I put together some notes I took and the binary images at KC Labs. Feel free to contact me about this… I plan to extend support for it a little bit and provide a toolchain and additional information.

Have a nice time!

PS: Sorry for the bad image this time, I had to use the webcam to capture it.

Linux Support for a Gem April 22, 2009

Posted by Florian in Devices, GPE, kernel concepts, Linux, OpenEmbedded.
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Some time ago I got a nice looking and interesting TOPAS910 evaluation board for the ARM based Toshiba TMPA910 series of SoCs. With its black PCB and golden labels for the expansion ports it is definitely the best looking evaluation board I have seen so far. But its interesting from a technical point of view as well and of course you can run Linux on it.

Topas 910 Board

Topas 910 Board

The TMPA910CRAXBG SoC on the board is based of an ARM9 core clocked with 200MHz and a pile of external interfaces such as:

  • TFT controller
  • USB client
  • NAND and NOR flash
  • SPI
  • Touchscreen
  • ADC
  • SD / MMC
  • UART

The board can be powered from the USB port, has Ethernet, a QVGA TFT display and all necessary interfaces to get started with the SoC.  Some details can be found here.

Board Details

Expansion Connectors

The initial Linux port was made by a company called BPlan known for their Amiga projects. They provide two ports: A real port to the hardware platform and one making use of some proprietary OpenFirmware-like bootloader. The latter is quite useless because it depends on calling its firmware for every hardware access but the 2.6.26 patch, bootloader and documentation they provide on their website are a good start. After a deeper look into the kernel patch it was clear that they left a lot of things to do: Only half of the TFT, NOR flash, USB, Ethernet anf the serial port are supported. It among other lacks a driver for SD, NAND, audio, the joypad and all the GPIO ports.

I wasn’t able to resist and started a small project to improve support for it. I have updated the kernel to 2.6.29, added gpiolib support and drivers for joypad and the small LED display which helped testing the GPIO drivers. Of course I have OpenEmbedded support for it ready and pushed upstream today – even if this still uses the old kernel it is useful to build a tiny userland that is able to live in NOR flash. Now I need to get some storage facility sich as SD or NAND flash working in order to deploy a proper filesystem image.

The TMPA910 is the chip in the BGA case in the center of the image.

The TMPA910 is the BGA case in the center of the image

I would be interested in getting to know any hardware that is using this TMPA910. The results of my work: Sources and a small demo image can be found at KC Labs. We haven’t announced it yet, but its there already: KC Labs is the new Open Source projects website at kernel concepts.


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!