// Include the AccelStepper library:
#include <AccelStepper.h>
//Motor interface type must be set to 1 when using a driver:
#define motorInterfaceType 1
// Create a new instance of the AccelStepper class:
AccelStepper stepper = AccelStepper(motorInterfaceType, 3, 2);
AccelStepper stepper1 = AccelStepper(motorInterfaceType, 5, 4);
AccelStepper stepper2 = AccelStepper(motorInterfaceType, 7, 6);

void setup() {
  // Set the maximum speed in steps per second:
  stepper.setMaxSpeed(1000);
  stepper1.setMaxSpeed(1000);
  stepper2.setMaxSpeed(1000);
  pinMode(A0, INPUT);
  pinMode(A1, INPUT);
  pinMode(A2, INPUT);
}
void loop() { 
  int pos = analogRead(A0);
  pos = map(pos, 0, 1022, 0, 90);

  int pos1 = analogRead(A1);
  pos1 = map(pos1, 0, 1022, 0, 90);

  int pos2 = analogRead(A2);
  pos2 = map(pos2, 0, 1022, 0, 90);

  while(stepper.currentPosition() >= pos){
    stepper.setSpeed(-400);
    stepper.runSpeed();
  }  
  while(stepper.currentPosition() != pos){
    stepper.setSpeed(450);
    stepper.runSpeed();
  }
  while(stepper1.currentPosition() >= pos1){
    stepper1.setSpeed(-400);
    stepper1.runSpeed();
  }  
  while(stepper1.currentPosition() != pos1){
    stepper1.setSpeed(450);
    stepper1.runSpeed();
  }
  while(stepper2.currentPosition() >= pos2){
    stepper2.setSpeed(-400);
    stepper2.runSpeed();
  }  
  while(stepper2.currentPosition() != pos2){
    stepper2.setSpeed(450);
    stepper2.runSpeed();
  }
}