File content as of revision 0:61f4586742be:

#include "mbed.h"

Motor motor1(D6, D7, D13, D12);             // Defining motor pins (PWM, direction, encoder)
Motor motor2(D5, D4, D10, D11);             // Defining motor pins (PWM, direction, encoder)

const double Kp = 10.0;
const double Ki = 0.1;
const double Kd = 0.5;

Ticker motor_cali;

void Motor_Calibration()
{
    float motor_angle1 = motor1.get_current_angle;
    motor_angle1--;
    motor1.set_target_angle(motor_angle1);   
    
    float motor_angle2 = motor2.get_current_angle;
    motor_angle2--;
    motor2.set_target_angle(motor_angle2);
}

int main()
{
    motor1.set_pid_k_values(Kp, Ki, Kd);    // Attach PID-controller
    motor2.set_pid_k_values(Kp, Ki, Kd);
    motor1.start(pid_period)                // Attach PID time
    motor2.start(pid_period);
    motor.attach(Motor_Calibration,0.5);    // Ticker for motor calibration fucntion
    while (true) {}                         // Empty while loop to keep function from stopping
}