automatic wire cutter

//------ librarys

#include <LiquidCrystal_I2C.h>
#include <Wire.h>
#include <Servo.h>

//------ lcd

LiquidCrystal_I2C lcd(0x27,16,2);

//------ stepper

#define stepPin 7
#define dirPin 8

//------ servo

Servo snippers;
#define servo 10
#define openAngle 180
#define closedAngle 0

//------ input

#define dellButton 5
#define leftButton 6
#define rightButton 7
#define upButton 8
#define downButton 9

//------ user settings

unsigned int wireLength = 0;
unsigned int wireQuantity = 0;

//------ system settings

int state = 0;
int incrementSpeed = 1;
int previousWireLength = 25;
int previousWireQuantity = 3;
float mmPerStep = 0.18096;

void setup() {
  Serial.begin(9600);
  lcd.init();
  lcd.backlight();

  pinMode(upButton, INPUT_PULLUP);
  pinMode(downButton, INPUT_PULLUP);
  pinMode(leftButton, INPUT_PULLUP);
  pinMode(rightButton, INPUT_PULLUP);

  pinMode(stepPin, OUTPUT);
  pinMode(dirPin, OUTPUT);

  snippers.attach(servo);

  snippers.write(openAngle);

  delay(1000);
}

void loop() {
  //Pokud je stisknute tlacitko „right“
  if(!digitalRead(rightButton)) {
    //a hodnota proměnné state = 5
    if(state == 5) {
      //uměníme hodnotu tate na 0 -> home screen
      state = 0;
    }
    else {
      //poku není zvýšíme hodnotu proměnné state o 1
      state += 1;
    }
    delay(200);
    lcd.clear();
  }
  //pokud je stisknuté tlačítko „left“ a hodnota proměnné state je mezi 0 a 4
  if(!digitalRead(leftButton) && state > 0 && state < 4) {
    //snizime hodnotu state o 1
    state -= 1;
    delay(200);
    lcd.clear();
  }

  //------ Menu
  switch(state) {
    case 0:
      homeScreen();
      break;
    case 1:
      chooseWireLength();
      break;
    case 2:
      chooseWireQuantity();
      break;
    case 3:
      confirm();
      break;
    case 4:
      currentlyCutting();
      break;
    case 5:
      finishedCutting();
      break;
  }
}

void homeScreen() {
  lcd.setCursor(0, 0);
  lcd.print("WIRE CUTTER");
  lcd.setCursor(0, 1);
  lcd.print("v1.1.0");
  lcd.setCursor(11, 1);
  lcd.print("NEXT>");
  delay(100);
}

void chooseWireLength() {
  wireLength = changeValue(wireLength);

  lcd.setCursor(0, 0);
  lcd.print("Length:" + (String)previousWireLength + "mm");

  //nejprve zobrazíme poslední nastavení
  if(previousWireLength >Ř 0) {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("LENGTH:" + (String)previousWireLength + "mm");
    if(!digitalRead(rightButton)) {
      wireLength = previousWireLength;
    }
  }
  if(!digitalRead(upButton)) {
    if(previousWireLength != wireLength) {
      lcd.clear();
      previousWireLength = wireLength;

      lcd.setCursor(0, 0);
      lcd.print("LENGTH:" + (String)wireLength + "mm");
    }
  }
  displayNavigation();
}

void chooseWireQuantity () {
  wireQuantity = changeValue(wireQuantity);

  lcd.setCursor(0, 0);
  lcd.print("Quantity:" + (String)previousWireQuantity + "pcs");

  //nejprve poslední nastavení
  if(previousWireQuantity > 0) {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Quantity:" + (String)previousWireQuantity + "pcs");
    if(!digitalRead(rightButton)) {
      wireQuantity = previousWireQuantity;
    }
  }
  if(!digitalRead(upButton)) {
    if(previousWireQuantity != wireQuantity) {
      lcd.clear();
      previousWireQuantity = wireQuantity;

      lcd.setCursor(0, 0);
      lcd.print("Quantity:" + (String)wireQuantity + "pcs");
    }
  }
  displayNavigation();
}

void confirm() {
  lcd.setCursor(0, 0);
  lcd.print((String)wireLength + "mm x " + (String)wireQuantity + "pcs");
  lcd.setCursor(0, 1);
  lcd.print("<BACK");
  lcd.setCursor(10, 1);
  lcd.print("START>");
  delay(100);
}

void currentlyCutting() {
  lcd.setCursor(0, 0);
  lcd.print((String)0 + "/" + (String)wireQuantity);
  lcd.setCursor(0, 1);
  lcd.print("???s");
  int stepsToTake = (int)wireLength/mmPerStep;
  for(int i = 0; i < wireQuantity; i++) {
    unsigned long timeForOneCycle = millis();
    digitalWrite(dirPin, HIGH);
    for(int x = 0; x < stepsToTake; x++) {
      digitalWrite(stepPin, HIGH);
      delayMicroseconds(500);
      digitalWrite(stepPin, LOW);
      delayMicroseconds(500);
    }

    lcd.setCursor(0, 0);
    lcd.print((String)(i+1) + "/" + (String)wireQuantity);

    snippers.write(closedAngle);
    delay(600);
    snippers.write(openAngle);
    delay(600);

    lcd.setCursor(0, 1);

    unsigned long timeRemaining = ((millis() - timeForOneCycle) * (wireQuantity - (i+1)))/1000;
    lcd.print((String) timeRemaining + "s    ");
  }
  previousWireLength = wireLength;
  previousWireQuantity = wireQuantity;
  state = 5;
}

void finishedCutting() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("CUTTING COMPLETE");
  lcd.setCursor(11, 1);
  lcd.print("NEXT>");
  delay(500);
  lcd.clear();
}

int changeValue(int currentValue) {
  if(!digitalRead(upButton)) {
    delay(100);
    currentValue += incrementSpeed;
  }
  if(!digitalRead(downButton)) {
    if(currentValue - incrementSpeed >= 0) {
      delay(100);
      currentValue -= incrementSpeed;
    }
    else {
      currentValue = 0;
    }
  }
  if(!digitalRead(downButton) && !digitalRead(upButton)) {
    incrementSpeed = 1;
  }
  return currentValue;
}

void displayNavigation() {
  lcd.setCursor(0, 1);
  lcd.print("<BACK");
  if(state ==1 || state ==2) {
    lcd.setCursor(7, 1);
    lcd.print("X");
  }
  lcd.setCursor(11, 1);
  lcd.print("NEXT>");
  delay(100);
}