Yeah I know, I've been howling a little about lack of funds and therefore lack of hardware. Good news, I have some servos on the way! Another 8 x 9MGS, none of the plastic rubbish that caused me most of the grief.

In the meantime, I still need a mobile platform to test the 3D vision system with. I've been looking at a tracked base because I have all the components laying around :

A pair of 1:70 gearboxes and 5v DC motors. This one is a piece of a kit but this mechanism could easily have been chopped out of a toy. It doesnt have any way of detecting the position. More on that later...

There is something raw about grabbing materials and a rule and prototyping out of your head. It leaves CAD completely cold.

Those kebab skewers are temporary, I'm trying to find something a little more substantial...

Interface it to the existing Origaime hardware and I'm now nearly ready to proceed where I left off due to the servos.

Life imitates art, a Wall-E made of trash :-)

The neck pitches and turns, the eyes focus and it will move on its tracks when I get the motors wired in.

Because they are DC motors I'll need to find a way to sense their position for basic metrics. There is no room in the gearbox for a magnet near the motor output shaft or any other way to read the motor revolutions. I could rip up an old mouse and use the encoders, but I've come up with an interesting alternative.

As the motor has a commutator it throws out a lot of EMF and needs suppressing. While I'm in there, I may as well sense the back-EMF using one of the MCU's analogue inputs and use that to determine rotation. I havent tried this yet, but I'm optimistic.