A smart BeagleBrick March 29, 2009Posted by Florian in Devices, GPE, Linux, OpenEmbedded.
Tags: BeagleBoard, GPE, Laser Keyboard, Linux, OpenEmbedded, PICO Projector
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.
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.
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!