Scarab-A Roomba for dog poop in a fenced-in yard
This project was named the Scarab not just for its resemblence to the dung beetle but for its functional similarity to that animal. In principal this machine is intended to wander around a fenced in yard and act as an autonomous turd-combine that deposits its treasure in a standard disposable grocery bag. In practice, picking up turd is a little more complicated than I've been able to master. The solution may be as simple as using a lower gear-down on the auger, or as complex as putting a 12v shop vac on it. The platform is a converted RC Tank base with two bumper switches and a simple offset-delayed electromechanical H-bridge pair for brains. Eventually I'd like to do a microprocessor version that can home in on a charging base (but the usability of IR outdoors worries me) or eventually use GPS to limit the unit to a yard that isn't fenced in.
I was going through my old files and discovered some media to add that, when I first posted this, I didn't have the LMR savvy/experience to include. Hope yall like it. As I mentioned, I originally called it the "Turd Hurler," so if that shows up in any files, well, you get the picture...
Just about as simple as you can get and still act like a Roomba. Here's what it looks like on the premade PCB. Not quite up to the level of acuity of BlueBeta or Sanc04 on similar perfboards, but it works.
This is where I began my practice of color-coding the wiring as much as possible, so where you see red it's probably Vcc and black is the ground rail. All this fits into the water-proof pelican case on the ass of the unit (the yellow box) and the wires have little filed channels that you have to push them into to get the damned thing to close. The terminal strip is on top of the battery compartment and it connects the "Brain" to the motors, battery, etc.
That's a pretty big file-I think if you click on it you'll see the unscaled version. I laid it out full-scale in AI CS3 to get a feel for the scale and how the pieces would fit together before the tank came to me. Obviously a lot of things changed.
Of course, it's a WIP probably forever. If I ever get back to it and fix the problem with its failure to pick up poop I might also upgrade it to μcontroller brains and ultrasonics (probably overkill and useless against chain link fences without the bumpers.)