How to control stepper motors with hc-rs04?

Question

Arduino

I wanted to make it so that when the ultrasonic sensor receives a signal at a distance of 20 cm, the code for the stop stepper motor works. hc-rs04 .

I tried like this:

#include <CustomStepper.h>        
#include <Ultrasonic.h>
CustomStepper stepper1(4,5,6,7); 
CustomStepper stepper2(8,9,10,11);
int example1 = 1; 
int example2 = 1;

Ultrasonic ultrasonic(12, 13);
int distance;
void setup()
{ 
   Serial.begin(9600);
 stepper1.setRPM(16);   //Для первого двигателя это stepper1              
  stepper1.setSPR(4075.7728395);  
   stepper2.setRPM(16);          //И для второго это stepper2      
  stepper2.setSPR(4075.7728395);

}

void loop()
{
 if (stepper1.isDone() and example1 == 1)  
  {
    stepper1.setDirection(CCW);        
    stepper1.rotate(1);                
  }
  stepper1.run(); 

       
 if (stepper2.isDone() and example2 == 1)  
  {
    stepper2.setDirection(CW);        
    stepper2.rotate(1);                
  }
  
  stepper2.run();      
  distance = ultrasonic.read();
  
  Serial.print("Distance in CM: ");
  Serial.println(distance);
  delay(1000);
if(Distance == 20){
stepper=0;
}else if(Distance!==20){
stepper.run();
}
}

Answer 1

Learn the controller language "State Graph", draw a program (there are parallel structures).
An example of Stateflow on MatLab (in Matlab there are examples of porting code to Arduino).