neuron photovore

Okay, okay, so neuron photovore sounds like a really complicated piece of equipment a doctor might use if he was operating on you or something, but really, the idea of this robot was to build a robot which looked for the brightest light source with the fewest components and as cheaply as possible (for obvious reasons :)). So, I made a circuit that consists of two "neurons" that are comprised of two op-amps (thats operational amplifiers, also known as comparators) linked together with a couple of CdS cells. CdS (Cadmium Sulfide) cells vary their resistance according to the amount of light they recieve, so they acted as perfect light sensors.

I started with building a test circuit, because the fewer components the easier it is to debug and rewire. I used some LEDs in stead of motors, basically, so I saved using some transistors and a secondary power supply. After I found the success of that simple circuit, I added two TIP 120 NPN transistors. They basically make up a simple ON/OFF motor control because the chips themselves aren't desined to provide high amounts of current as a motor requires. Of course there are a few resistors here and there. Six total, actually. Two of them are 4.7k, two 3.9k, and two 1k ohm resistors, all are quarter watt, and all are +/- 5% as usual. The two cadmium sulfide cells are the standard ones from radio shack that you can but in a five pack for a few bucks.
The schematic for the entire thing will be coming up as soon as I can get around to scanning the drawing of it, but if you already know your way around the 741, it should be no problem to make it up yourself, or find it online somewhere. For now, here is a basic parts layout:

As far as the servos are concerned, they are what I consider to be gutted. They are not hacked, per say, but literally gutted. Instead of taking out the stop and replacing the potentiometer with a few resistors, I completely took all the circutry out, and just soldered the positive and negative wires on to the motors, respectively. This turns them into just plain old motors with a gearbox attatched, but it sure beats any othergearboxes I have been able to find, especially the little POS things that taimya is selling. (Okay, I take that back, I did enjoy the twin motor gearbox, but thats it!)

Okay, as far as furthering this almost robot, I do have plans. I, first of all, am going to replace the two 741s with an LM339 quad comparator to reduce size and increase expandability by 2 "neurons". Also, I think once I get a good schematic, I will solder it all into one nice little board with some smaller motors. Also, in the works is some *simple* object avoidance using whisker switches. So basically, I am taking everything I know how to do with the BASIC stamp and trying to get them into a hardware (not software) based robot.

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