Arduino dc motor in sync with servo motor

Projects Programming
1

I have this simple arduino code that drives two Dc motor using L298N which is a motor driver together with two servo motors. The code is working fine for the motor driver but not for the servo motor:

#include <Servo.h>

Servo myservo;
Servo myservo2;
int num=1;
int IN1=8;
int IN2=9;
int ENA=3;

int IN3=10;
int IN4=11;
int ENA2=4;

void setup()
{
  myservo.attach(40);
  myservo2.attach(42);

 pinMode(IN1,OUTPUT);
 pinMode(IN2,OUTPUT);

 pinMode(IN3,OUTPUT);
 pinMode(IN4,OUTPUT); 
}
void loop()
{
   intialPos();    

 while(motor_run())
  {
        turnOne();
       delay(3000);
       intialPos();
       delay(10000);
       turnSecond();
       delay(3000);
  } 

}
int motor_run()
{

  analogWrite(ENA, 1500);// motor speed  
  digitalWrite(IN1,LOW);// rotate forward
  digitalWrite(IN2,HIGH);

  analogWrite(ENA2, 1500);// motor speed  
  digitalWrite(IN3,HIGH);// rotate forward
  digitalWrite(IN4,LOW);

  delay(3000);
  return (1);
}
void intialPos()
{
  myservo.write(70);
   myservo2.write(135);
  delay(2000);
}
void turnOne()
{
  myservo2.write(170);
  myservo.write(135);
  delay(2000);
}
void turnSecond()
{
  myservo2.write(70);
  myservo.write(30);
  delay(2000);
}

My problem is to make the dc motor code continues to execute while the servo motor do its thing which is turning. But all it does was to make the dc motor work and the servo motors are unmoving. I'm using the servo motor as a rudder in a boat so I need to make the dc motor continuously working while the servo motor turns to a direction. I've heard multi threading but it is not supported on arduino. I found another way to make them in sync with each other which is using cycle or timing, but the sample code was confusing so can someone give me a code snippet and some detailed explanation for it. And please don't give me the blinking lights sample of cycle timing.

2

delay(any number) - just say NO !

The delay() function does what it says and delays everything for the period specified. You need to use a different timing strategy to make several thing appear to happen at once.

Read and understand Several things at the same time

The principle is simple. Record the start time of an event then check each time through loop() whether the relevant period has elapsed. If no, check again next time round. If yes, act on it.

3

even without delay the servo motor won't do its task while the dc motor is executing its work.

4

kmonterde:
even without delay the servo motor won't do its task while the dc motor is executing its work.

Please post the code without delays that shows the problem.

5 
int motor_run()
{
  return (1);
}

Why? What is the point of returning the same value EVERY time the function is called?

 while(motor_run())

How is this EVER supposed to end? Get rid of the while statement!