File content as of revision 4:f36406c9e42f:

#include "mbed.h"
#include "math.h"
#include "MODSERIAL.h"

DigitalIn button(SW2);
DigitalOut directionpin1(D7);
DigitalOut directionpin2(D8);
MODSERIAL pc(USBTX, USBRX);

Ticker ticker;

volatile bool emg0Bool = false;
volatile bool emg1Bool = false;
volatile bool emg2Bool = false;
volatile bool y_direction = true;
volatile bool a;

volatile float x_position = 0.0;
volatile float y_position = 0.0;
volatile float old_y;
volatile float old_x;
volatile int motor1_angle = 0;
volatile int motor2_angle = 0;
volatile int direction;
volatile char c;

const float length = 0.300; //length in m (placeholder)
const int C1 = 3; //motor 1 gear ratio (placeholder)
const int C2 = 3; //motor 2 gear ratio
      
void xDirection() {
    //direction of the motion
    if (emg0Bool && !emg1Bool) { //if a is pressed and not d, move to the left
        directionpin1 = true;
        directionpin2 = true;
        direction = -1;
    }
    else if (!emg0Bool && emg1Bool) { //if d is pressed and not a, move to the right
        directionpin1 = false;
        directionpin2 = false;
        direction = 1;
    }

    if (emg0Bool || emg1Bool){
        //calculating the motion
        old_x = x_position;
        x_position = old_x + direction;
        motor1_angle = asin( x_position ) / length;     //theta = arcsin(x) / L
        
        old_y = y_position;
        y_position = old_y + direction;
        motor2_angle = acos( x_position ) / length;     //theta = arcsin(x) / L
    }
    
    //reset the booleans
    emg0Bool = false;
    emg1Bool = false;
}

void yDirection () {      
    if (emg2Bool) { //if w is pressed, move up/down
        //direction of the motion
        if (y_direction) { 
            directionpin2 = true;
            direction = 1;
        }
        else if (!y_direction) {
            directionpin2 = false;
            direction = -1;
        }
        
        //calculating the motion
        old_y = y_position;
        y_position = old_y + direction;
        motor2_angle = C2 * y_position;
        
        //reset the boolean
        emg2Bool = false; 
    }
}

int main() {
    pc.baud(115200);
    pc.printf(" ** program reset **\n\r");
    
    while (true) {
        //if the button is pressed, reverse the y direction
        if (!button) {
            y_direction = !y_direction;
            wait(0.5);
        }
        
        //testing the code from keyboard imputs: a-d: left to right, w: forward/backwards
        a = pc.readable();
        if (a) {
            c = pc.getc();
            switch (c){
                case 'a': //move to the left
                    emg0Bool = true; 
                    break;           
                case 'd': //move to the right
                    emg1Bool = true;
                    break;            
                case 'w': //move up/down
                    emg2Bool = true;
                    break;
            }
        }
        xDirection(); //call the function to move in the x direction
        yDirection(); //call the function to move in the y direction
        
        // print the motor angles
        pc.printf("motor1 angle: %i\n\r", motor1_angle);
        pc.printf("motor2 angle: %i\n\r\n", motor2_angle);

        wait(0.25f); //can also be done with ticker, to be sure that it happens exactly every 0.5 seconds
    }
}