File content as of revision 0:11d0f3e0d1ad:

/**
Name: mpi hunter
Description:

Based on work done by Giles Barton-Owen
Cut down for use at Linton Village College

This program keeps a m3pi inside a ring and looks for the other robot (and runs away from it)

**/

#include "mbed.h"
#include "SharpDigiDist100.h"
#include "m3pi.h"

DigitalOut Left[2] = {LED1,LED2};           //Some indicator LEDs for the range finders
DigitalOut Right[2] = {LED4,LED3};

SharpDigiDist100 right(p30);                // The range finder class initialisations
SharpDigiDist100 left(p11);

m3pi m3pi;                                  // Initialise the m3pi

InterruptIn button(p21);                    // SW1 on the shield, for strategy switching

Ticker guidance;                            // The main guidance caller

Serial pc(USBTX, USBRX);                    // For debugging and pc messages, uses commented out to prevent hanging

int previousLine;                           // A set of variables to sort out the line detection, previousLine is pretty much not used
int isLine;
int lineCatch;

Timeout liner;                              // A timeout to stop it ignoring the line

void CycleMode();                           // Function defs
void guideCall();
void clearLiner();


int main() {
    guidance.attach(&guideCall,0.1);        // Sets up the control loop
    
    m3pi.locate(0,0);                       // Write the name to the screen
    m3pi.printf("m3PiRngr");                
    
    m3pi.get_white_levels();                // Saves the current levels of the sensors to know what is white
    
    while (1) {
       
        switch (right.getDistance()) {      // Sets up the distance indicator LEDs for the right side
            case SharpDigiDist100::Far :
                Right[0] = true;
                Right[1] = false;
                break;
            case SharpDigiDist100::Near :
                Right[1] = true;
                Right[0] = false;
                break;
            case SharpDigiDist100::Mid :
                Right[0] = true;
                Right[1] = true;
                break;
            default:
                break;
        }
        switch (left.getDistance()) {       // Sets up the distance indicator LEDs for the left side
            case SharpDigiDist100::Far :
                Left[0] = true;
                Left[1] = false;
                break;
            case SharpDigiDist100::Near :
                Left[1] = true;
                Left[0] = false;
                break;
            case SharpDigiDist100::Mid :
                Left[0] = true;
                Left[1] = true;
                break;
            default:
                break;
        }
}
}
void guideCall() {

    isLine = m3pi.is_line();            // Gets whether the m3pi is on a line, and if so front/back
    
    if (lineCatch == 0) {               // Has it been off a line for long enough?
        isLine = isLine;                // Yes - then go ahead
    } else {
        isLine = lineCatch;             // No - pretend to still be on that line
        
    }
    float position;                     
    
    switch (isLine) {
        case 0:                         // No line, not even recently so go ahead with the strategies
            {
            bool atRight = false;
            bool atLeft = false;
             
                    if (right.getDistance() == SharpDigiDist100::Near) {
                        atRight = true;
                    } else atRight = false;
                    if (left.getDistance() == SharpDigiDist100::Near) {
                        atLeft = true;
                    } else atLeft = false;
         
                   if (atRight && atLeft) {
                        m3pi.backward(0.5);
                    } else {
                        if (atRight == true) {
                            m3pi.left_motor(-0.3);
                            m3pi.right_motor(-0.5);
                        } else {
                            if (atLeft == true) {
                                m3pi.left_motor(-0.5);
                                m3pi.right_motor(-0.3);
                            } else {
                                m3pi.stop();
                            }
                        }
                    }
                    }   
             break;       
        case 1:                 // Line in front, reverse
            if (lineCatch == 0) {
                lineCatch = 1;

                liner.attach(&clearLiner, 0.3);
            }

            position = m3pi.line_position();
            if (position < 0) {
                m3pi.left_motor(-1);
                m3pi.right_motor(-0.8);
            } else if (position == 0) {
                m3pi.backward(1);
            } else if (position > 0) {
                m3pi.left_motor(-0.8);
                m3pi.right_motor(-1);
            }

            //m3pi.locate(0,1);
            //m3pi.printf("LINE_FWD");
          

            break;

        case -1:            // Line behind, forward

            if (lineCatch == 0) {
                lineCatch = -1;
                liner.attach(&clearLiner, 0.3);
            }


            position = m3pi.line_position();
            if (position < 0) {
                m3pi.left_motor(1);
                m3pi.right_motor(0.8);
            } else if (position == 0) {
                m3pi.forward(1);
            } else if (position > 0) {
                m3pi.left_motor(0.8);
                m3pi.right_motor(1);
            }
 
            break;
    }

    //previousLine = isLine;
}

void clearLiner() {             // Gets called a bit after a line is detected
    lineCatch = 0;
}