07
Jul 10

andi-servo

As I mentioned in my last post, part of building Dagda required me to write a linux device driver for the Ajeco ANDI-SERVO motion control board:

ANDI-SERVO motion control board

After only eleven years, I finally got round to releasing the code for that driver under the MIT licence using Google Code project hosting.

How much use it would be to anyone is up for debate – the current version of the ANDI-SERVO is still in production, but differs from the model I developed on; the driver was written for Linux 2.0.35 and hasn’t been updated; and it’s pretty basic at that. Still, better out there than thrown away 🙂

The board itself is described in this datasheet; the main chip at it’s core, the actual device the driver is controlling, is described in this datasheet, this programming guide, and this user guide. Those, and the first edition of Alessandro Rubini’s excellent book Linux Device Drivers, were the main references for writing the driver.

The documentation I wrote for this was actually in LaTeX because I was still learning it at the time, but here’s the pdf it translated into. There’s only four pages, but they cover the structure and basics of the driver and the code’s simple enough to follow.

Speaking of code, it’s in a mercurial repository. You can browse it on the Google Code project webpage or clone it with hg like so:

hg clone https://andi-servo.googlecode.com/hg/ andi-servo

Enjoy, and I hope someone finds it useful…


22
Jun 10

Dagda – part two (cameras and computers)


So the last post was all about the mechanical chassis and frame and power systems; this time I want to look at the cameras and the computer.

The cameras we used were standard research ones we had in the lab at the time – fairly straightforward things, whose resolution would now be too low to be used on the most basic mobile phone (and which were strictly grayscale only), but which were fairly high end at the time:

Hitachi KP-M1

They were small and light, which was a plus, but they needed special cables and power supply boxes, which was a bit of a pain:

Hitachi KP-M1 rearHitachi KP-M1 power supply boxes

Still, they let us get video reasonably cheaply. We did have another camera sensor, mounted on the very top, which Niall Winters was using for his PhD which was on Omnidirectional Video – it was one of the first panaspheric cameras, and again, mostly home-made:

Dagda's Omnidirectional Camera Continue reading →


16
Jun 10

Dagda


Meet Dagda, which represents a good few years of my past life!

Dagda It occurred to me recently that I’ve never put any details of the robot up on the web, so I figured I might as well correct that! Continue reading →