File content as of revision 15:1d440beb24d3:

#include "mbed.h"

#include "autocar.h"

DigitalOut led1(LED1); // LED indicating the car is running
DigitalIn pb(PC_13); // triggter button
int lastButtonState = 0;
bool ledState = false;

// output used for controlling motors
DigitalOut M1_enable(D6);
DigitalOut M2_enable(D5);
DigitalOut M1_in1(D3); // connected to left wheel
DigitalOut M1_in2(D2); // connected to left wheel
DigitalOut M2_in3(D1); // connected to right wheel
DigitalOut M2_in4(D0); // connected to right wheel

// input used for IR sensors
extern AnalogIn leftIR(A1); // left sensor
extern AnalogIn middleIR(A3); // middle sensor
extern AnalogIn rightIR(A5); // right sensor

// PID control params
int values = 0;
float Kp = 0.2, Ki = 0.0001, Kd = 1;

// main() runs in its own thread in the OS
int main()
{
    bool left = false;
    bool middle = false;
    bool right = false;

    // here I use 500 as threshold
    int threshold = 500;

    // set two motors to stop
    init();

    while (true) {
        int reading1 = pb.read();

        if(reading1 != lastButtonState) {
            wait_ms(20);

            int reading2 = pb.read();

            if(reading2 == reading1) {
                lastButtonState = reading2;
            }

            if(lastButtonState == 1) {
                ledState = !ledState;
            }
        }

        led1.write(ledState);

        if(ledState) {
            // not on track: > 500
            // on track (black): < 500
            readIR(&left, &middle, &right, threshold);
            //values = readIRValues(); // read IR values

            driveMotor(left, middle, right);
            //driveMotorPID(values, Kp, Ki, Kd);
        }
    }
}