#include <Stepper.h>
#include <LiquidCrystal_I2C.h>

#define ENCODER_CLK 2
#define ENCODER_DT 3
#define ENCODER_SW  4
#define BUTTON_PIN 5

LiquidCrystal_I2C lcd(0x27, 20, 4);
const int stepsPerRevolution = 200;
Stepper stepperMotor(stepsPerRevolution, 8, 9, 10, 11);

int lastClk = HIGH;
int counter = 0;
int steps = 0;
int RPM = 0;
int maxRPM  = 4800; // ??????????????
/*
int potpin = 0;  // analog pin used to connect the potentiometer
int val;    // variable to read the value from the analog pin
 int newPosition;
 int lastPosition = analogRead(potpin);

 int throttleChange = false;

void readRPM(){
  val = analogRead(potpin);            // reads the value of the potentiometer (value between 0 and 1023)
  val = map(val, 0, 1023, 0, 50);
  stepperMotor.step(val);
}
*/

void readEncoder() {
  int dtValue = digitalRead(ENCODER_DT);
  if (dtValue == HIGH) {
    counter++; // Clockwise
    stepperMotor.step(1);
  }
  if (dtValue == LOW) {
    counter--; // Counterclockwise
    stepperMotor.step(-1);
  }
}

// Get the counter value, disabling interrupts.
// This make sure readEncoder() doesn't change the value
// while we're reading it.
int getCounter() {
  int result;
  noInterrupts();
  result = counter;
  interrupts();
  return result;
}

int getPosition() {
  int result;
  noInterrupts();
  result = counter;
  interrupts();
  return result;
}

void resetCounter() {
  if (counter!=0)
    stepperMotor.step(-counter);
  noInterrupts();
  counter = 0;
  interrupts();
}

void lcdUpdate(int steps, int counter){
  lcd.setCursor(0, 0);
  lcd.print("RPM:");
  lcd.setCursor(9, 0);
  //lcd.print(getCounter());
  lcd.print(steps,10);
  lcd.setCursor(0, 1);
  lcd.print("Position:");
  lcd.setCursor(9, 1);
  lcd.print(counter,10);
  //lcd.print("        ");
}

void setup() {
  // set the speed at 60 RPM:
  stepperMotor.setSpeed(500);
  // initialize the serial port:
  //Serial.begin(9600);
  // encoder part
  Serial.begin(115200);
  // Initialize LCD
  lcd.init();
  lcd.backlight();

  pinMode(ENCODER_CLK, INPUT);
  pinMode(ENCODER_DT, INPUT);
  pinMode(ENCODER_SW, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(ENCODER_CLK), readEncoder, FALLING);

  //readRPM();

  pinMode(BUTTON_PIN, INPUT_PULLUP);
  int value = HIGH;
  while (value==HIGH){
    stepperMotor.step(-1);
    value = digitalRead((BUTTON_PIN));
}
}

void loop() {
  if (digitalRead(ENCODER_SW) == LOW) {
    resetCounter();
  }
  /*
  newPosition = analogRead(potpin);
  newPosition = map(newPosition, 0, 1023, 0, 50);
  RPM = map(newPosition, 0, 50 , 0, 5600);
  lcdUpdate(RPM,newPosition);
  //if (newPosition != lastPosition) {
    // There was a change on the CLK pin
    if (newPosition > lastPosition) {
      //newPosition = map(val, 0, 1023, 0, 50);
      //steps = newPosition;
      stepperMotor.step(newPosition-lastPosition);
    }
    if (newPosition < lastPosition) {
      //newPosition = map(val, 0, 1023, 0, 50);
      //steps = newPosition;
      stepperMotor.step(-(lastPosition-newPosition));
    }
    lastPosition = newPosition;
    throttleChange = true;
    */
  //}
  //Serial.println(analogRead(potpin),DEC);
  //Serial.println(lastPosition,DEC);
  //Serial.println(RPM,DEC);
  //delay(100);
  /*
  if (digitalRead(ENCODER_SW) == LOW) {
    resetCounter();
  }
*/
  /*
  val = analogRead(potpin);            // reads the value of the potentiometer (value between 0 and 1023)
  val = map(val, 0, 1023, 0, 50);
  stepperMotor.step(val);
  val = 0;
  Serial.println(analogRead(potpin));
  */
  // step one revolution  in one direction:
  //Serial.println("clockwise");
  //stepperMotor.step(1);
  //delay(500);
/*
  // step one revolution in the other direction:
  Serial.println("counterclockwise");
  stepperMotor.step(-stepsPerRevolution);
  delay(500);*/
  /*
  int dtValue = digitalRead(ENCODER_DT);
  if (dtValue == HIGH) {
    counter++; // Clockwise
    stepperMotor.step(1);
  }
  if (dtValue == LOW) {
    counter--; // Counterclockwise
    stepperMotor.step(-1);
  }*/
/*
  // encoder part
  int newClk = digitalRead(ENCODER_CLK);
  if (newClk != lastClk) {
    // There was a change on the CLK pin
    lastClk = newClk;
    int dtValue = digitalRead(ENCODER_DT);
    if (newClk == LOW && dtValue == HIGH) {
      stepperMotor.step(10);
      //counter++; // Clockwise
      Serial.println("Rotated clockwise ⏩");
    }
    if (newClk == LOW && dtValue == LOW) {
      stepperMotor.step(20);
      //counter--; // Clockwise
      Serial.println("Rotated counterclockwise ⏪");
    }
  }*/
}