Since my last post here I've mainly finished the mechanical construction of Android 9. I've got a few bits left to tidy up but I've now moved onto the electronics to control it. I'm using mainly Picaxe microcontrollers because they are cheap and have lots of built in functions like RS232 / PWM etc - a bit like a very low cost Basic Stamp on one chip (~$5/10). They are also pin-for-pin compatable with a standard pic (since that's what they are made from).

The basic summary for control is that the side-to-side leaning joints at the ankles are compleatly passive, i.e. no motors. The android will be dynamically stable, getting feedback from a GWS PG-03 gyro so that the hip motors can push it's weight off centre onto each leg in turn, but not tipping so far it falls over, even with momentum builds up. To start, effectively the gyro will act as a kind of safety switch to kill the momentum if the android leans too far outside a predefined safety zone.

I've already started building the picaxe/Gyro 'warning alarm'/measuring circuit so there should be something working soon...