//https://docs.arduino.cc/built-in-examples/digital/Debounce/
#include <Wire.h> 
#include <LiquidCrystal_I2C.h>

#define I2C_ADDR    0x27
#define LCD_COLUMNS 16
#define LCD_LINES   2

LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);


int led=4;
int b = 2;
int val=0,led_num=0;
int ledstate=LOW; //initial value ledState
int buttonState;            // the current reading from the input pin
int lastButtonState = LOW;
unsigned long lastDebounceTime = 0;  // the last time the output pin was toggled
unsigned long debounceDelay = 70; 
void setup() 
{
pinMode(led,OUTPUT);
pinMode(b, INPUT);
lcd.begin(16,2);
lcd.backlight();
}
void loop(){
  //read the value of the button when pressed
   int reading = digitalRead(b);

  // check to see if you just pressed the button
  // (i.e. the input went from LOW to HIGH), and you've waited long enough
  // since the last press to ignore any noise:

  // If the switch changed, due to noise or pressing:
  if (reading != lastButtonState) {
    // reset the debouncing timer
    lastDebounceTime = millis();
  }

  if ((millis() - lastDebounceTime) > debounceDelay) {
    // whatever the reading is at, it's been there for longer than the debounce
    // delay, so take it as the actual current state:

    // if the button state has changed:
    if (reading != buttonState) {
      buttonState = reading;

      // only toggle the LED if the new button state is HIGH
      if (buttonState == HIGH) {
        ledstate = !ledstate;

       if(buttonState){ //button is pressed
    led_num=led_num+1; //add 1 to the led_num variable
                      }
  
  if (led_num==1){
    lcd.clear();
    lcd.setCursor(0,0); 
    lcd.print(" Mode 1 "); 
                       }
  else if (led_num==2){
    lcd.clear();
    lcd.setCursor(0,0); 
    lcd.print(" Mode 2 ");
                     }
  else if (led_num==3){
    lcd.clear();
    lcd.setCursor(0,0); 
    lcd.print(" Mode 3 ");

    //reset the led_num variable to 0
    led_num=0;         }

      }
    }
  }

  // set the LED:
  digitalWrite(led, ledstate);
lastButtonState = reading;
  // save the reading. Next time through the loop, it'll be the lastButtonState:

 
  }

/*
void loop(){
  //read the value of the button when pressed
  val=digitalRead(b);

  //in this example, the value of the button when pressed is 1
  if(val==1){
    //reverse the current state of the ledstate variable
    ledstate=!ledstate;
    //the ledstate variable controls the HIGH or LOW state
    digitalWrite(led,ledstate); 
    if (ledstate==HIGH){
      lcd.clear(); //erase all text on the lcd
      lcd.setCursor(0,0);
      lcd.print("LED is ON");}
    else{
      lcd.clear();
      lcd.setCursor(0,0);
      lcd.print("LED is OFF");
      }
    //wait .5 second before the next reading
    delay(500);
  }
}*/