// This one has the easiest logic of all 
#include <AccelStepper.h>
#define HALFSTEP 8
#define rightButton 8         //the adjust pin
// Change the pin defination if you want to
#define motorPin1  9     // IN1 on the ULN2003 driver 1
#define motorPin2  10     // IN2 on the ULN2003 driver 1
#define motorPin3  11    // IN3 on the ULN2003 driver 1
#define motorPin4  12    // IN4 on the ULN2003 driver 1
// Initialize construtor with pin sequence IN1-IN3-IN2-IN4 for using the AccelStepper with 28BYJ-48
AccelStepper stepper1(HALFSTEP, motorPin1, motorPin3, motorPin2, motorPin4);

void setup()
{
  Serial.begin(4800);   //Remember from the Serial communication tutorial
  stepper1.setMaxSpeed(1000);
  stepper1.setAcceleration(1000);
  stepper1.setSpeed(1000);
  stepper1.moveTo(4096); // 4096*10 steps for 10 rotations in 28BYJ-48 – 5V Stepper Motor
  //I hope you all to adjut the direction again within 10 rotations.....if no plzz feel free to disconect and connect again the microcontroller
}//--(end setup )---

void loop()
{
  while(Serial.available() == 0);    //Loops in this line until the funtion gets any data from the Serial buffer
  char data = Serial.read();
  if(data == 'g')     // 'g' means GO ......to switch on the Stepper after data is recieved from Atmega 3 to Atmega 2
   trigger_go_go_go();
  if(data == 's')  // 's' will be sent which signifies STOP .......this lets you syncronize the stepper
  {
   stepper1.stop();      // First stop the motor plzz
   adjust();    // lets you syncronize the stepper
  }
}

void trigger_go_go_go()  // Check out adjust() first, then you can easily understand
{
  stepper1.move(4096);
  while(Serial.available()==0)
  {
    if(stepper1.distanceToGo() == 0)
      trigger_go_go_go();    // recursion to call itself until something is caught in the Serial Monitor
    go_go_go();           // Runs the stepper step by step
  }
  loop();                // loop() is called when some thing is sent through Serial communication
}
  
void go_go_go()           // just required to move the stepper 
{
  stepper1.run();          // Moves 1 step per call
}

void adjust()                 // Executes if and only iff there is no Serial data coming in
{
  stepper1.move(4096);
  while(Serial.available() == 0)
  {
    if(stepper1.distanceToGo() == 0) // when the stepper reaches step 4096 calls adjust() [recursion]
       adjust();
    if(digitalRead(rightButton) == HIGH)  //when the right switch is pressed the stepper moves when unpressed stops automatically
       go_go_go();
  }
  loop();                    // this actually means a if statement.....i.e. if(Serial.available!=0)
}
  
  
/////////// thats it for the 1st Atmega /////////////