File content as of revision 6:dd0a91c2994f:

#include "mbed.h"

Serial blue(PTC4,PTC3);

//motor select pins
DigitalOut motor_lf(PTE2);
DigitalOut motor_lb(PTE3);
DigitalOut motor_rf(PTE4);
DigitalOut motor_rb(PTE5);


DigitalIn input(PTC1);  //input from sensor array
DigitalOut Line_right(LED_GREEN);//no line detected
//DigitalOut blue(LED_BLUE);

BusOut sensor(PTD7,PTE1,PTE0);//multiplex sensors
AnalogOut level(PTE30);//set comparator level needs to be tuned for each sensor (could create program)


//Frequency of Pulse Width Modulated signal in Hz
#define PWM_FREQ          1000

//PWM pin (Enable 1 and 2)
PwmOut motor_l (PTC2);
PwmOut motor_r (PTE29);

//LED to test
DigitalOut led(LED_RED);

void sensor_select(int x)//converts int to hex for display
{
    switch(x) {
        case 0:
            sensor = 0x2;
            break;
        case 1:
            sensor = 0x1;
            break;
        case 2:
            sensor = 0x0;
            break;
        case 3:
            sensor = 0x3;
            break;
        case 4:
            sensor = 0x5;
            break;
        case 5:
            sensor = 0x7;
            break;
        case 6:
            sensor = 0x6;
            break;
        case 7:
            sensor = 0x4;
            break;
    }

}
int sensor_read()
{
    int val=0;
    level = 0.3;
    int x = 0;

    //static int values[8];
    while( x <= 3 ) { //why 3? Don't you want to select through 8 sensors therefore x<=7? 
        sensor_select(x);
        //blue = !blue;
        wait(0.1);
        
        if (input == 1) {
            val=val+2^x; //could you comment on what this is for? 
        } else {
            val=val;//+2^x;
        }
        x=x+1;
        
    }
    blue.printf("%i\n",val);
    return val;
}


void set_direction( int direction, float speed, float angle)
{
   

    float r_result = (speed + angle); //where angle can be postive and negative and will TURN the robot
    float l_result = (speed - angle); //if turning left, you'd make the angle postive (right motor goes faster left motor goes slwoer)
    switch( direction ) {
        case 0x11: { //forward
            motor_r.write(  r_result  < 0 ? 0    :     r_result > 1 ? 1    :       r_result);
            //Look up ternary statements -- {condition ? value_if_true : value_if_false} This makes 0<result<1
            motor_l.write(  l_result < 0 ? 0     :     l_result > 1 ? 1    :       l_result);

            motor_rf=1;
            motor_rb=0;
            motor_lf=1;
            motor_lb=0;
        }
        case 0x00: { //backward
            motor_r.write( r_result  < 0 ? 0    :     r_result > 1 ? 1    :       r_result);
            motor_l.write( l_result  < 0 ? 0    :     l_result > 1 ? 1    :       l_result);

            motor_rf=0;
            motor_rb=1;
            motor_lf=0;
            motor_lb=1;
        }
        case 0x01: {  //spin left  --     Right forward, left backward
            motor_r.write( r_result  < 0 ? 0    :     r_result > 1 ? 1    :       r_result);
            motor_l.write( l_result  < 0 ? 0    :     l_result > 1 ? 1    :       l_result);

            motor_rf=1;
            motor_rb=0;
            motor_lf=0;
            motor_lb=1;
        }
        case 0x10: {    //spin right
            motor_r.write( r_result  < 0 ? 0    :     r_result > 1 ? 1    :       r_result);
            motor_l.write( l_result  < 0 ? 0    :     l_result > 1 ? 1    :       l_result);

            motor_rf=0;
            motor_rb=1;
            motor_lf=1;
            motor_lb=0;
        }
    }
}

void change_direction( int sensor_values) //right hand sensors only
{
    //Line_right = !Line_right;
    switch( sensor_values ) {
        case 0x00: { //no lines robot is lost!!!!
            set_direction(0x11, 0.0, 0.0);
            wait(1);
            break;
        }
        case 0x01: { //to far left turn right 0001
            set_direction(0x11, 0.5, 0.0); //this doesn't turn right; this goes straight at half speed
            wait(1);
            Line_right = !Line_right;
            break;
        }
        case 0x02: {  //left turn right       0010
            set_direction(0x11, 0.0, 0.0);
            wait(1);
            break;
        }
        case 0x03: {  //far left turn right   0011
            set_direction(0x11, 0.0, 0.0);
            wait(1);
            break;
        }
        case 0x4: {    //right turn left      0100
            set_direction(0x11, 0.0, 0.0);
            wait(1);
            break;
        }
        case 0x5: {    //unknown **           0101
            set_direction(0x11, 0.0, 0.0);
            break;
        }
        case 0x6: {    //perfect              0110
            set_direction(0x11, 0.0, 0.0);
            wait(1);
            break;
        }
        case 0x7: {//corner junction or plate 0111
            set_direction(0x00, 0.0, 0.0);
            wait(1);
            break;
        }
        case 0x8: {//to far right turn left   1000
            set_direction(0x11, 0.0, 0.0);
            wait(1);
            break;
        }
        case 0x9: {    //unknown              1001
            set_direction(0x11, 0.0, 0.0);
            wait(1);
            break;
        }
        case 0xA: {    //unknown              1010
            set_direction(0x11, 0.0, 0.0);
            break;
        }
        case 0xB: {    //unknown              1011
            set_direction(0x11, 0.0, 0.0);
            wait(1);
            break;
        }
        case 0xC: { //far right turn left     1100
            set_direction(0x11, 0.0, 0.0);
            wait(1);
            break;
        }
        case 0xD: {    //unknown              1101
            set_direction(0x11, 0.0, 0.0);
            break;
        }
        case 0xE: {    //corner or plate      1110
            set_direction(0x00, 0.0, 0.0);
            wait(1);
            break;
        }
        case 0xF: {    //corner               1111
            set_direction(0x11, 0.0, 0.0);
            wait(1);
            break;
        }
    }
}
int main()
{
//Set PWM frequency to 1000Hz
    motor_l.period( 1.0f / (float) PWM_FREQ);
    motor_r.period( 1.0f / (float) PWM_FREQ);
//Initialise direction to nothing.
    motor_rf=0;
    motor_rb=0;
    motor_lf=0;
    motor_lb=0;
    

    while(1) {
        led = !led;
        int values;
        
        values = sensor_read();
        
        change_direction(values);
        
    }
}