I have been toying with this idea for a while and I will throw it out there to see if it even holds up to the piclist scrutiny. What do you think about teaching the bot the first time? With heading information from a compass and wheel rotation information from encoders, the bot would build a table of heading changes vs wheel rotations the first time (starting from a home position). One would use a joystick to mow the lawn the first time. The bot records the wheel position every time the heading changes by a certain amount. The second time around, the bot would head out in the first heading direction until it reaches the wheel rotation figure for the next heading change, change to the new heading and so on. Of course, the problems I see right away are wheel slippage and noise from the compass. But for arguments sake, if I could solve those problems, do you see any other potential pitfalls for this method. The merits of this method are that you do not need to depend on any external markers. Teach it one lawn ( even multiple lawns using a selector switch) and let it go from a know position every time. One might have to re-teach it every so often if the bot starts wandering into the flower patch.... Anyway, does the method seem feasible?...winter is coming and I need to go into hibernation in my basement lab... Madhu -----Original Message----- From: pic microcontroller discussion list [mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Jinx Sent: Friday, August 31, 2001 8:26 AM To: PICLIST@MITVMA.MIT.EDU Subject: Re: [EE]: - Botboard > How are you planning the cutting path ? The most successful I've seen is tracking a buried wire. Not sure what the signal is but the demo looked pretty good. If you edged the area with white (painted bricks ? logs ?) you could perhaps use optics. Industrial robots follow a white line around their work area -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics