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My other robots
I built at least eight of them. there are two ancient ones I consider interesting enough for this `homepage':
Willie is Dizzy's immediate ancestor. He is only about smart enough to find the 25 W lightbulb marking his batterycharger.
The charger stands near a wall and is equipped with two metal wires, each describing half of a circle, one above the other, the upper one having the larger radius. Willie grabs them with his two vertical `fingers'. The moment contact is made, a current flows into his battery, and his motors stop.
The search for the lightbulb requires more than simply looking for a stronger light. Dizzy moves while rotating around his normal axis, continuously scanning a full circle around itself. The strongest light will allways be most attractive. But Willie needs to find a particular light source, which may not be the strongest one. Therefore he tries to `lock on' to the first point of light he sees, until his fingers find the charger or his feelers hit an obstacle. Evasive action is taken carefully: first he backs up a little, then he turns less than 45 degrees away from the touched feeler, trying to avoid losing target lock.
Often the light he's found proves to be disappointing. Reflections of sunlight on white objects are particularly attractive, but supply no food at all. To avoid a fatal hang-up, Willie measures his collision frequency. If his feelers touch more than seven times within 40 seconds, he closes his eyes for a while, in order to blindly wander away from the false light.
Originally it was my intention to have Willy resemble a biological pet, by covering him with synthetic fur. In the coat I wanted to hide a large number of thin copper wires. When touched by a caressing hand, Willie would stop and make a purring sound. The circuit for all of this was built into the prototype, but I never got around to the hairy finish...
Many people have requested Willy's fourteen years old schematic. I don't think it is relevant anymore, as a cheap and low power AT90S1200 uC can easily give you more functionality than I achieved all those years ago with six ICs and a couple of diodes. But if you really want to have a look, here you are.
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