#include <Stepper.h>

//ULN2003
const int speedPBInc  = 18; //define input pin
const int stopPB = 5; //define input pin for Stop push button
const int speedPBDec = 4; //define input pin
const int motorPin[] = {19, 21, 22, 23};
const int direction = 0; //0 for CW, 1 for CCW;
const int stepsPerRevolution = 200;  // change this to fit the number of steps per revolution
int speedStep = 1;
int stepMinimum = 40;
int stepMaximum = 178;
int stopType = 0; //0=fully stopped , 1=hold (consumes energy)
int currentSpeed = 115;
int currentSPR = stepsPerRevolution;
#define START 1 //
#define STOP 0
#define CW 1
#define CCW -1
#define MotorInterfaceType 8
int motorStopState = START; //change if you need to
// initialize the stepper library on pins 8 through 11:
Stepper myStepper(stepsPerRevolution, motorPin[0], motorPin[1], motorPin[2], motorPin[3]);
//----------------------------------------------------------------------
void setup() {
  myStepper.setSpeed(115);
  // initialize the serial port:
  Serial.begin(9600);
  pinMode(speedPBInc, INPUT_PULLUP);
  pinMode(stopPB, INPUT_PULLUP);
  pinMode(speedPBDec, INPUT_PULLUP);
  //attachInterrupt(digitalPinToInterrupt(stopPB), stopMotor, FALLING);
}
//----------------------------------------------------------------------
void loop() {
  updateState();
  if (!motorStopState) {
    currentSPR = 0;
  }
  else {
    currentSPR = stepsPerRevolution;
  }
  myStepper.setSpeed(currentSpeed);
  if (direction == 1)  {
    myStepper.step(-currentSPR);
  }
  else {
    myStepper.step(currentSPR);
  }
}
//----------------------------------------------------------------------
void updateState() {
  if (digitalRead(stopPB) == LOW)  {
    motorStopState = 1 - motorStopState; // stop the motor
    if (motorStopState  == STOP)    {
      stopMotor();
    }
    delay(500);
  }
  if (digitalRead(speedPBInc) == LOW)  {
    motorStopState = START;
    currentSpeed += speedStep;
    Serial.println(currentSpeed);
    if ( currentSpeed >= stepMaximum )
      currentSpeed = stepMaximum ;
  }
  if (digitalRead(speedPBDec) == LOW)  {
    motorStopState = START;
    currentSpeed -= speedStep;
    Serial.println(currentSpeed);
    if ( currentSpeed < stepMinimum )  currentSpeed = stepMinimum ;
  }
}
//----------------------------------------------------------------------
void stopMotor(){
  if (stopType == 0)  {
    for (int i = 0; i < 4; i++)    {
      digitalWrite(motorPin[i], LOW);
    }
  }
}