Say hello to Little Keith, an unholy marriage of Lego, Arduino and breadboarding:
Here’s another view of the little blighter:
Some details. He’s powered by an arduino at the back there, and hardware wise he’s got:
- two L293 motor controllers (the two chips on breadboard)
- two bidirectional drive motors controlled by one of the chips, geared down a fair bit – each motor has three control wires
- two photoresistors, one on each side, just for fun
- an HC-SR04 cheap ultrasonic proximity detector, mounted on a panning head (which makes him bear a remarkable resemblance to Wall-E)
- a third motor controlling the head, geared down a lot
- a crude encoder – you can see it at the back there – based on a red LED shining through a hole at a photoresistor, which is occluded every time a bar, coupled to the pan motor, sweeps by it.
- too many damn wires – three for each motor, for starters.
The motors are standard Lego motors, connected to the breadboard by wires made by cutting standard Lego connectors in half and soldering header pins onto one end. Works pretty well.
As far as the software goes, I’m using it as a test for a subsumption framework in C++, hopefully not using too much memory by using function passing to define the wiring. I’ll let you all know how it goes.
Oh yes – I’m aware that putting such a crappy little sensor on a panning head is almost pointless given what the FOV of the damn thing is likely to be :)