This is pretty neat; I had the impression that they were going to make something like this, but kinda put it out of my mind after hearing nothing about it for y

This is pretty neat; I had the impression that they were going to make something like this, but kinda put it out of my mind after hearing nothing about it for years. I found an old Friendly Robotics lawn mower robot on Craigslist and purchased it for $50, thinking of using it for my lawn but I never got around to doing anything with it. Mainly because I couldn't think of an easy way to detect the perimeter of the lawn without an edge wire! I guess it's not an easy problem to solve. I had considered a bunch of options, a few of the ideas I had were: 1. Some kind of camera or color sensor, looking downward, to detect "green" vs "non-green" - assuming the grass was green and non-grass would be some other color. That would work ok for most of my yard, but my lawn in front doesn't have an "edge" with the neighbor's lawn - so it would mow their lawn, too - not what I want. 2. A passive perimeter, consisting of a bunch of spaced (maybe 6" between?) magnets - I thought maybe plastic golf tees with a rare-earth magnet glued on top would be ok; then use hall-effect sensors on the robot's perimeter to determine if it had crossed over the line of magnets. 3. This one was more to detect cut vs uncut grass - but use some kind of humidity sensor; assuming cut grass has higher humidity than uncut grass, "sniff" the ground and avoid uncut (drier) areas. The problem with this concept, mainly, was in not being able to find high-speed humidity sensors/detectors. At any rate, I never followed through with any of this, but maybe someday I might return to it? I am curious on the cost of this iRobot lawn mower, though. I'm guessing 4 figures, given what I know about the price of their vacuums (which my wife loves; every time one dies, she buys a new one, and the old one I save for my future Roomba army to take over the world with). If my guess is accurate, then I'll just have to put off buying one, as it will still be cheaper to continue to pay my landscaper to cut my lawn (and this robot won't trim trees or bushes yet, so...)