Niklas,
        If you are trying to position from within a room it becomes not so difficult. If outside of a controlled environment,
good luck. Use a hall effect to determine North. Then use a sonar sensor to measure distance from the walls  at North,
South, East and west. One sensor can work with a 360 stepper. You can also use this sensor to determine if objects are
in front of robot as it moves. Objects such as chairs and tables may introduce some problems. However if the furniture
has not been moved, the robot can manipulate it way around the obstacles to get back to a point that all four
measurements will be correct.

Gordon Varney
www.iamnee.com

>
> I wonder if there's anyone that have any good? ideas about small-scale
> positioning?
> Scenario: You have a small robot walking around finding obstacles. When you
> find
> these you want to store the position.
> As this is just a hobby thing it can't cost too much so things like gps is
> not in
> question, if even applicable.
>
> TIA
> Niklas
>

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads