Tuesday, October 19, 2010

Android and Contraption

Back in July I wrote briefly about Cascada, my little project to move my software developed as part of my Diminuto project from the AT91RM9200-EK board (which uses the Atmel AT91 ARM9 processor) to the smaller, much cheaper, and more powerful BeagleBoard (which uses the TI OMAP 3530 ARM11 processor) with the TinCanTools Zippy2 expansion board. Cascada turned out to be so straightforward, I was a little disappointed. I didn't really feel like I'd gotten the learning experience I'd expected.

So I evolved the project into Contraption, where I run the "Rowboat" port of Android, the Google mobile device environment, to the BeagleBoard. This would have been a no-brainer too had I not insisted on getting the Zippy2 Ethernet port working. That required I reverse engineer the configurations of the Angstrom U-Boot bootloader and Linux kernel for the BeagleBoard that support the Zippy2, use what I learned to build the Linux that come with Android (which is slightly different), substitute in the U-Boot that initializes the Zippy2, and get the whole mess running on my hardware.

A few evenings of head scratching, and the next thing you know I'm displaying my blog on the Android browser.


Scattered around my tiny lab bench is (roughly left to right) a WiFi to Ethernet bridge (which will play a role in a later article), the tiny BeagleBoard, an Ethernet switch, a BDI3000 JTAG debugger (mostly unnecessary), a fan (also mostly unnecessary except to keep me cool), and a powered USB hub. The keyboard and mouse on the left are connected to an ancient ThinkPad I use as a window and TFTP server, and the smaller keyboard and mouse on the right are connected to the BeagleBoard. Below is the Android home screen running on the BeagleBoard.

Google Android ("Rowboat") on BeagleBoard

Why Android? Lots of reasons, but the most compelling was that I had come across a technical report written by some students at the University of Applied Sciences Northwestern Switzerland about using Android in industrial automation. I'm all about frameworks for real-time software design, and this was right up my alley. It will also be an excuse to brush up my Java skills and learn how to develop in the Android environment.

Somewhat ironically, since I've spent the past nearly fifteen years working for one Bell Labs spin-off or another, my interest in Android is not really related to mobile phones. I have a whole other project in mind. But that will have to wait for a future article.

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