Thanks very much to all for the array size stuff, I'm using the bit array to
store my potentials and wall data, so cutting down on memory, but will put in
my project that another type of chip would be more appropriate.

<using HiTech PICC-LITE under MPLAB for a PIC16F84A>

For the current pic i'm going to use the dead simple 'follow-the-left-hand-
wall' technique. I've written the basic code, but at the moment its a case
of "move 1 square, stop. read sensors. go again", so I'm trying to setup an
interrupt on RB0 so that when the Left-Hand Sensor changes, I can jump to the
decision code.

As yet my program runs and compiles but doesn't do anything on a change to B0.
I've kind of pieced the code I need together from the PICCLITE manual and other
tutorials, and can see there's stuff about option registers, but nothing I've
tried has made a difference. Code to try out the interrupt is below.

void interrupt sensor()
{
        int i;
        PORTA=255;
        for (i=40;i--;) continue;
}

main()
{
        TRISA=0;
        TRISB=3;

        //OPTION=192;        tried fiddling with this code but I'm just
        //INTCON|=(1<<GIE);             guessing really...

        for (;;)
        {
        PORTA=0;
        }
}

Simple stuff no doubt, but any ideas??? cheers,
john

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.