Re: <obstacles> Ok. If you used 2 motors in m1(right) & m3(left) , and your sensor was at  the front (and only one), and in port 15, a short program for running it  could be: /*Start of avoid.c */ void main(){    while(1){    /*Puts program in an infinite loop*/     fd(1); fd(3); /* Drives the robot forward */      while(analog(15<100){ /*Approaching an obstacle */         off(1); bk(1); /* Turns robot right */ } }  } /*End of avoid.c */ Of course, if there's more than one sensor or whatever, you'd make the  appropriate changes. And 100 might not be the number you want to use, too. -Kate > Dearest kate > I am using infra red sensor which return value from 255 to 0. 255 when > it does not sense any thing and valve reduces when there is any thing in > front. lowest valve is 0. >  >  >  >  > Kind Regards >  > Sincerely, > Javaid Iqbal >  > On Mon, 14 Sep 1998 krasing@iastate.edu wrote: >  > > I don't really know how to explain finite state machines (FSMs) or parse  > > trees...(I'm not in computer science...) but my artificial life class's  > > homepage is still up and the text is available through it in post-script  > > format (http://www.math.iastate.edu/danwell/math378.html). > >  > > To everyone that wants my "hard code" - I need to know what kind of  > > sensors you're using and whether or not your environment is a set one.  > > Also, my evolving code is much better at obstacle avoidance than the hard  > > code. (It's not as hard as it may sound!) > >  > > -Kate > > --- > > Kate > > krasing@iastate.edu > >  > > > >There's many ways you can approach obstacle avoiding. > > >  > > > >There are neural nets, evolutionary code (incl. genetic programming and  > > > >genetic algorithms), finite state machines, and there's hard-coding it into  > > > >the program (which, of course is no fun at all but such a headache saver!). > > >  > > > >I have some code available, somewhere, that I can dig up - I have a  > > > >hard-code version in IC, an evolving FSM code in C++, and a half-finished  > > > >evolving parse tree in IC (note: use a more recent edition that has  > > > >multi-dimensional arrays. so much easier). > > > > > >  Hi, do you mind sending your hard-code version to me? I would like to have > > >  a look. I'm currently writing the program for my obstacle avoidance robot > > >  running on 2 steppers and a HB.  > > >  > > >  Btw, what is finite state machines and parse tree?  > >  > >  > >  > >  >