A major milestone has now been reached in the project: All of the custom hardware & firmware modules have been designed, prototyped and tested. I've just finished work on the last of these, the Motor Control Module, which generates high frequency PWM signals for the two main DC drive motors, and decodes the signals from two quadrature encoders. The interface with the host mainboard, as always, is I2C. The functionality of the Motor Control Module has been scaled back somewhat from what was originally planned. Originally, the Motor Control Module was to contain firmware for PID closed-loop control, and for keeping track of the robot's pose. Now, this functionality will be a part of the "driver" layer (more on this below) which runs on the host mainboard.
I've already started work on the next layer of software, a "driver" that communicates with the robot's hardware modules. The driver acts as an abstraction layer, which represents the hardware to "client" code as a collection of standard interfaces. I'm writing this driver to fit into the Player robot server framework. Such is the magic of Player, that once the driver has been written, it should be possible to "plug in" pre-written Player-ready algorithms and code modules into the robot. They will interact with the Open Automaton Project hardware via the standard interfaces.
Now that all the custom hardware modules are done, the prototype is about ready for final assembly. There are a few more holes to drill and wires to run, but I should be able to get this done over the next couple of days, so it'll certainly be ready for the Robothon.
The prototype will be on static display at the Robothon, and I've prepared a two-sided flyer that I'll be handing out at the event, which briefly introduces the project to interested visitors.
Here's a PDF draft of the flyer: oap.pdf (feedback is welcome; it's not been printed yet; dafydd at walters dot net).
The Big Move
There are just nine more days left before the movers come to put all my worldly belongings into a 20-foot freight container, leaving my family and I with just a few suitcases, my laptop, some books and essential tools, and of course, the robot. Then we're off on a leisurely 5-day drive up the coast to Seattle in a rented SUV, which will be our last chance to enjoy this country's scenery before we head back to the UK.