#include <AccelStepper.h>
/*
 * stepper control through big easy driver
 * positions are expressed in centimeters
 * originPos is near the motor, where switchLow gets LOW
 * maxPos is the maximum position, where switchHigh gets LOW
 * idlePos is the idle position
 * lowOffset 
 * highOffset are offsets from originPos/maxPos respectively to define the running zone
 * 
 * Stepper driven through big easy driver
 * configured for 1/4 microstepping (mover micro-steps gives low speed)
 * 800 steps is one rotation
 * one rotation is 1.6cm translation
 * cm to steps ratio is 500 
 */

 // Define a stepper and the pins it will use
AccelStepper stepper(1, 8, 7);

// microswitch pins
int switchLow = A5;

int speedLimit[2] = { 50 , 1000 } ;// sets an absolute minimum/maximum speed limit
int accLimit[2] = { 100, 2000} ;

long int moveTo_Stepper(long int stepto ) {
  stepper.moveTo( constrain( stepto , originPos * stepToCm, maxPos * stepToCm ) );
  return stepper.distanceToGo();
}
float moveToCm_Stepper(float cmto ) {
  stepper.moveTo(constrain( cmto * stepToCm , originPos, maxPos ));
  return stepper.distanceToGo()/stepToCm;
}

long int move_Stepper(long int stepRelative ) {
  stepper.move(stepRelative);
  return stepper.distanceToGo();
}
float moveCm_Stepper(float cmRelative ) {
  stepper.move(cmRelative * stepToCm );
  return stepper.distanceToGo()/stepToCm;
}

long int maxSpeed_Stepper(long int maxspeed){
  stepper.setMaxSpeed( constrain (maxspeed, speedLimit[0], speedLimit[1] ) );
  return stepper.maxSpeed();
}

long int acceleration_Stepper( long int acc ){
  stepper.setAcceleration(acc + 1); // prevent 0 step/s²
  return acc;
}

//////////////// CALIBRATION ////////////////////////

float init_Stepper(){
  //run at constant speed until hitting switchLow
  stepper.setSpeed(-1*speedLimit[1]); 
  while(digitalRead(switchLow)) {
    stepper.runSpeed();
  }
  stepper.stop();
  //this is the new 0 step
  stepper.setCurrentPosition(0);



  delay(1000); //take a breath

  //run at constant speed until hitting switchHigh
  stepper.setSpeed(speedLimit[1]);
  while(digitalRead(switchHigh)) {
    stepper.runSpeed(); 
  }
  stepper.stop();
  maxPos = stepper.currentPosition() / stepToCm ;

  delay(1000);

  stepper.runToNewPosition(maxPos * stepToCm / 2) ; 
  return maxPos ;
}

///////////////////// SETUP ///////////////////////////
void setup_Stepper(){
  pinMode (switchLow, INPUT_PULLUP);
  pinMode (switchHigh, INPUT_PULLUP);
  stepper.setMaxSpeed(speedLimit[1]);
  //stepper.setSpeed(10000);
  stepper.setAcceleration(accLimit[1]);
}

///////////////////// LOOP ///////////////////////////

bool update_Stepper() {
  
  bool updated = 1 ;
  stepper.run();
  
  if (!digitalRead(switchLow)) {
    stepper.setCurrentPosition(0);
    updated=0;
  }
  if (!digitalRead(switchHigh)) {
    stepper.setCurrentPosition(maxPos * stepToCm);
    updated=0;
  }
  return updated ;
}