The Explorer bot is a simple litter robot based on the Skitter's circuit and as its name implies it explores rooms avoiding obsticles. It has a very simple circuit and can be made out of junk sense the values of the parts is not specific.
Please note that the values of R1 and R2 are suggested to be 100K or more.
The explorer moves around the room until one of its senors are triggered the it stops the corrisponding motor and moves away from what triggered it.