First some basics: servo motors are what I’ll be using to provide movement for the robot. Each leg will consist of at least three servo motors (1 at the knee and two at the hip). As you’ll see from the wikipedia link above, servo motors are generally controlled by pulse width modulation. In order to control multiple servos you need to generate a continuous PWM control signal for each servo.

So far most of my more interesting components have been purchased from Cool Components mainly because they’re UK based and they stocked stuff I was interested in. I found them via SparkFun which is a treasure trove of fun; unfortunately I can’t find UK distributors for much of the stuff they have available and at present I’m trying to avoid buying bits and pieces for this project from the US as the shipping is often more expensive than the order.

I saw these Dynamixel DX servos mentioned on Trossen Robotics this morning, see here. They’re interesting because they have a richer interface than the normal hobby servos that I’ve been looking at and they provide a multidrop RS485 interface so that you can chain multiple servos together and control them individually via a single line. You can get feedback on the angular position, velocity and torque and also alerts if temperature and voltage deviate from expected (user specified) ranges.

Micromagic systems do robotics and animatronics for the film and tv industry and have quite a nice selection of hexapod robots. It’s especially interesting to see the evolution of their robots here. Their latest stuff is very impressive and puts into perspective how much I have to learn… Their robotics store (http://www.hexapodrobot.com) is also full of useful information.

This is the kind of thing that I mean when I say ‘hexapod robot’. I particularly like the head and mandibles. More details can be found here: http://forums.trossenrobotics.com/showthread.php?t=2762 and here: http://blog.trossenrobotics.com/index.php/2009/03/17/a-pod-a-robot-ants-tale/

Hi, my name is Len Holgate and this is a blog about my new project to design and build a hexapod robot; a mechanical vehicle that walks on six legs… By day I design and build high performance TCP and UDP servers for the Windows platform, my C++ technical blog is here: www.lenholgate.com. Up until a few weeks ago I’d never done any electronics or embedded programming; I decided that I needed a new hobby and so started tinkering with electronics, breadboarding and the like and, in what tends to be my typical approach to such things, I decided that the best way to push myself into this new hobby was to dive in to reasonably complex project.