/*
  Rotary Encoder volume control example

  Usage: rotate the knob to control the value,
  click the knob to change between volume/bass/treble.

  https://wokwi.com/arduino/projects/304919215794553409

  Released under the MIT license.
  Copyright (C) 2021, Uri Shaked.
*/


#include <LiquidCrystal_I2C.h>


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

uint8_t volume = 50; 
uint8_t bass = 25;
uint8_t treble = 66;
uint8_t repeat = 5;

typedef enum {
  SET_VOLUME,
  SET_BASS,
  SET_TREBLE,
  SET_REPEATE,
} Mode;

Mode mode = SET_VOLUME;
LiquidCrystal_I2C lcd(0x27, 20, 4); // set the LCD address to 0x27 for a 16 chars and 2 line display



void nextMode() {
  switch (mode) {
    case SET_VOLUME:
      mode = SET_BASS;
      break;

    case SET_BASS:
      mode = SET_TREBLE;
      break;

    case SET_TREBLE:
      mode = SET_REPEATE;
      break;

    case SET_REPEATE:
      mode = SET_VOLUME;
      break;
  }
}

void updateValue(int delta) {
  switch (mode) {
    case SET_VOLUME:
      volume = constrain(volume + delta, 0, 100);
      break;

    case SET_BASS:
      bass = constrain(bass + delta, 0, 100);
      break;

    case SET_TREBLE:
      treble = constrain(treble + delta, 0, 100);
      break;

    case SET_REPEATE:
      repeat = constrain(repeat + delta, 0, 100);
      break;
  }
}



void updateDisplay() {
  lcd.clear();

  lcd.setCursor(1, 0);
  lcd.print("Move : ");

  lcd.setCursor(7, 0);
  lcd.print(volume);

  if (mode == SET_VOLUME) {
    lcd.setCursor(0, 0);
    lcd.print(">");
  }


  lcd.setCursor(1, 1);
  lcd.print("Down : ");

  lcd.setCursor(7, 1);
  lcd.print(bass);
  if (mode == SET_BASS) {
    lcd.setCursor(0, 1);
    lcd.print(">");
  }



  lcd.setCursor(1, 2);
  lcd.print("Speed: ");

  lcd.setCursor(7, 2);
  lcd.print(treble);
  if (mode == SET_TREBLE) {
    lcd.setCursor(0, 2);
    lcd.print(">");
  }


  lcd.setCursor(1, 3);
  lcd.print("Count: ");

  lcd.setCursor(7, 3);
  lcd.print(repeat);
  if (mode == SET_REPEATE) {
    lcd.setCursor(0, 3);
    lcd.print(">");
  }


}

void setup() {
  pinMode(ENCODER_CLK, INPUT);
  pinMode(ENCODER_DT, INPUT);
  pinMode(ENCODER_SW, INPUT_PULLUP);
  updateDisplay();


  lcd.init();                      // initialize the lcd
  // Print a message to the LCD.
  lcd.backlight();

  lcd.clear();

  lcd.setCursor(1, 0);
  lcd.print("Move : ");

  lcd.setCursor(7, 0);
  lcd.print(volume);

  if (mode == SET_VOLUME) {
    lcd.setCursor(0, 0);
    lcd.print(">");
  }


  lcd.setCursor(1, 1);
  lcd.print("Down : ");

  lcd.setCursor(7, 1);
  lcd.print(bass);
  if (mode == SET_BASS) {
    lcd.setCursor(0, 1);
    lcd.print(">");
  }



  lcd.setCursor(1, 2);
  lcd.print("Speed: ");

  lcd.setCursor(7, 2);
  lcd.print(treble);
  if (mode == SET_TREBLE) {
    lcd.setCursor(0, 2);
    lcd.print(">");
  }

  lcd.setCursor(1, 3);
  lcd.print("Count: ");

  lcd.setCursor(7, 3);
  lcd.print(repeat);
  if (mode == SET_REPEATE) {
    lcd.setCursor(0, 3);
    lcd.print(">");
  }

}

long int modeLastChanged = 0;
int prevClk = HIGH;
void loop() {
  if (digitalRead(ENCODER_SW) == LOW && millis() - modeLastChanged > 300) {
    modeLastChanged = millis();
    nextMode();
    updateDisplay();
  }

  int clk = digitalRead(ENCODER_CLK);
  if (clk != prevClk && clk == LOW) {
    int dt = digitalRead(ENCODER_DT);
    int delta = dt == HIGH ? 1 : -1; // increment count by 1 or decrement by -1
    updateValue(delta);
    updateDisplay();
  }
  prevClk = clk;
}