#include <AccelStepper.h>
#include <MultiStepper.h>
#define stepsPerRevolution 800
#define motorCount 4
#define maxSpeed 1000
bool target = false;
int line = 0;
AccelStepper motors[]={
  {1,2,3},
  {1,5,6},
  {1,8,9},
  {1,11,12},
};

MultiStepper steppers;
long revs[motorCount];

void setup() {
  //initialise serial coms.
  Serial.begin(9600);
  Serial.println("rev1,rev2,rev3,rev4 +ve for cw, -ve for ccw");
  Serial.println("eg: 2,2,-0.5,-0.5 is two revolutions clockwise on motors 1&2 and half a revolution ccw on motors 3&4.");
  for (int i=0; i<motorCount; i++){
    motors[i].setMaxSpeed(maxSpeed);    
    steppers.addStepper(motors[i]);
  }  
}

void loop() {
  // does not block, allows user to modify position before target is reached
  steppers.run();
  // does block, allows user to modify position only after target is reached
  //steppers.runSpeedToPosition();
  for(int i=0; i<motorCount; i++){
    if (motors[i].distanceToGo() == 0 && target == true){
      Serial.println("next");
      target = false;
      delay(2500);
    }
  }
}
void serialEvent() {
  
  for (int i=0; i<motorCount; i++){
    revs[i] = round(stepsPerRevolution*(Serial.readStringUntil(',').toFloat()));  
  }
  
  steppers.moveTo(revs);
  target = true;
  //for (int i=0; i<motorCount-1; i++){
  //  Serial.print(revs[i]/800);  
  //  Serial.print(",");  
  //}  
  //Serial.println(revs[motorCount-1]/800);
}