/* ----------------------------------------------------------
*  Encoder_KY-040_Upgraded_V2.ino
*  without using interrupt for Encoder SW pin
*
*  How to use Rotary Encoder KY-040 in Arduino 
*  to set a counter value. The incremental value 
*  can be changed by pressing the encoder button
*  with the change value in units, tens, hundreds and thousands
*
*  By : Rilles Eko Prianto
*  ----------------------------------------------------------
*/
#include <LiquidCrystal_I2C.h>

// unchanged variables
int pinA = 2;
int pinB = 4;
int pinBtn = 5;
int bzr(8);
const String mul[4]={"UNITS", "TENS", "HUNDREDS", "THOUSANDS" };
const int MIN_COUNTER = 1;
const int MAX_COUNTER = 3000;
LiquidCrystal_I2C lcd(0x27, 16,2);

byte tanda[4][8] = {
{
	0b00000,
	0b00000,
	0b00000,
	0b00000,
	0b00000,
	0b00000,
	0b00000,
	0b01110
},
{
	0b00000,
	0b00000,
	0b00000,
	0b00000,
	0b00000,
	0b01110,
	0b00000,
	0b01110
},
{
	0b00000,
	0b00000,
	0b00000,
	0b01110,
	0b00000,
	0b01110,
	0b00000,
	0b01110
},
{
	0b00000,
	0b01110,
	0b00000,
	0b01110,
	0b00000,
	0b01110,
	0b00000,
	0b01110
}};

// variables that changed
float counter = 1;
volatile byte fired = 0;
volatile byte sA = 0;
int dir = 1;  //-1 = turn left 1 = turn right
byte tekan = 0;
byte step = 0;

void setup() {
  pinMode(pinA, INPUT_PULLUP);
  pinMode(pinB, INPUT_PULLUP);
  pinMode(pinBtn, INPUT_PULLUP);
  pinMode(bzr, OUTPUT);
  digitalWrite(bzr,0);

 
  lcd.init();
  // turn on the backlight
  lcd.backlight();
  for (int i=0;i<=3;i++) lcd.createChar(i, tanda[i]);

  lcd.setCursor(0,0);
  lcd.print(" HELLO, WELCOME");
  lcd.setCursor(0,1);
  lcd.print("   TO ARDUINO"); 
  delay(1000);
  lcd.clear();
  //         0123456789012345
  lcd.print("CNT: ");
  lcd.print(counter,0);
  lcd.setCursor(15,0);
  lcd.write(0);

  Serial.begin(115200);

  // set interrupt for encoder CLK pin
  attachInterrupt(digitalPinToInterrupt(pinA), isr, CHANGE);
  
  sA = digitalRead(pinA);
  // Serial.println("Arduino ready....");
  delay(1000);
}

void loop() {
  if (fired) {
    // if (dir==1) Serial.print("-->>"); else Serial.print("<<--");
    
    fired = 0;
    
    counter += dir * (pow(10,step));  // using pow()--> return var type must be float
    
    // the value of counter is limitted within range 0-3000
    counter = constrain(counter, MIN_COUNTER, MAX_COUNTER);
    lcd.setCursor(5,0);
    lcd.print("      ");
    
    lcd.setCursor(5,0);
    lcd.print(counter,0);
    
    // Serial.println(counter); 
  }
  
  if (digitalRead(pinBtn)==LOW){tekan=1; delay(15);}
  if (tekan){
    step++;
    bell();
    if (step>3) step = 0;
    // Serial.println(mul[step]);
    lcd.setCursor(15,0);
    lcd.write(step);
    delay(100);
    tekan = 0;
  }

}

void isr(){
  byte stateA = digitalRead(pinA);
  byte stateB = digitalRead(pinB);

  
//  if (stateA != sA){                   // use this if running on physical Arduino
  if (stateA != sA && stateA==LOW){     // use this if running on simulator
    if (stateA != stateB) dir = 1; else dir = -1;
    fired = 1;
  }
 sA = stateA ;
}

void bell(){
  tone(bzr, 4000);
  delay(40);
  noTone(bzr);
}