brainstorming

Bill SC

Hello all. I have a project in mind and was hoping you guys could give me some ideas based on your own experience ( I am relatively inexperienced). I am thinking of building a bot that would weed eat around a fenced in yard. I am looking at using either a propeller or a PC onboard. What do you guys think the pluses and detractions of these are, or would some other silicon be more suited? What do you think of navigation with encoders, sensors, RFID tags, GPS, etc, or simply controlling navigation off board with a PC over Bluetooth, ethernet, or transceiver? I know that I am being very vague, but as I said, I am just brainstorming here. My main experience is with the BOE BOT, but its inability to do more than one thing at a time is what has me looking at the other chips. Any ideas or links would be greatly appreciated. The real point is to learn while having fun, but building something useful is· an acceptable side effect, eh?

Mike Green

Your main issue will be navigation. GPS is simply not precise enough for these distances. It probably doesn't matter what kind of processor you plan to use. You will likely use some kind of DC motor and a motor controller like the HB-25 which doesn't require the constant "feeding" of the servo motors of the BotBot. A Propeller certainly has much more power than a Stamp. Have a look at the information (and videos) on the Propeller QuadRover. It's "overkill" for your application, but might give you some ideas.

Bill SC

Thanks, Mike. I don't think that I want to invest quite that much money into it, but any and all ideas are both welcome and appreciated. So you think that the Propeller is a good route for the brain, esp. as opposed to offboard?

Mike Green

On the on-board vs. off-board question ... What do you have to do that would require a PC to perform? I can imagine doing sophisticated video analysis on a large, fast workstation, but that's probably all that would require that amount of computing power. A Propeller can manage large files of data on an SD card or USB memory stick. There's not much other processing that a robot like this would require.

Bill SC

I was looking at ways to navigate... sensors with onboard versus offboard position determining with RFID tags, for example. I have looked at some pc based programs that I thought might serve (such as VCRIB), the idea being to break the yard up into virtual zones, and let the local navigation be handled by the Prop, or whatever onboard brain is present. I need you guys to guide me away from the impractical and impossible. This is only a hobby project, so I can brain storm as long as it takes to find a viable path before aquiring the necasary hardware and software. All I am looking at doing is building a wheeled platform that would move about the yard and weed eat. No video analysis. I don't have any approach set in stone. I thought that I would sort through the most plausible scenarios before limiting my options. I notice the QuadRover uses a gas engine and hydralics, I have seen lawnmowers that are gas, hybrid, and all electric. I have read about a buried wire deal for lawnmowers, but have not found them online yet. I am just trying to pick the brains of the gurus such as yourself.