// Program written by Dan Hostler, October 2020.
// Feel free to use as you need to.
// PayPal donations appreciated at danhostler1985@yahoo.com


// LIBRARIES
#include <Wire.h>               // deals with I2C connections
#include <LiquidCrystal_I2C.h>  // activates the LCD I2C library

// MENU ARRAYS
String menuOption[] = {{"OverVoltage"}, {"CutOffVoltage"}, {"Setting 3"}, {"Setting 4"}, {"Setting 5"}}; // Text on the top line
String measurementType[] = {{"[Volt]"}, {"[VOLT]"}, {"[POUNDS]"}, {"[INCHES]"}, {"[MPH]"}};  // Text on the bottom line

// PINS ON THE ARDUINO.
// MAKE THESE "CONST INT" VARIABLES AS THESE DO NOT CHANGE IN THE PROGRAM.
const int leftButtonPin = 5;       // Pin 5 for "Left" command
const int rightButtonPin = 6;      // Pin 6 for "Right" command
const int upButtonPin = 7;         // Pin 7 for "Up" command
const int downButtonPin = 8;       // Pin 8 for "Down" command
const int enterButtonPin = 9;      // Pin 9 for "Enter" command
const int clearButtonPin = 10;     // Pin 10 for "Clear" command

// NUMBER COUNT OF BUTTON PRESSES AND COUNTER UNITS.
// MAKE THESE A "INT" VARIABLES TO ALLOW FOR NEGATIVE INTEGERS.
int setting1Counter = 0;    // Counters for settings 1 - 5
int setting2Counter = 0;
int setting3Counter = 0;
int setting4Counter = 0;
int setting5Counter = 0;
int directionPush = 0;      // This counter changes the menu option with each "left" or "right" button push.
int upPressCount = 0;       // This counter measures the amount of times the user pushes the "up" button.
int downPressCount = 0;     // This counter measures the amount of times the user pushes the "down" button.

// BUTTON PRESS STATES FOR EACH FUNCTION, ALL SET TO "LOW".
// MAKE THESE "BOOLEAN" VARIABLES AS THESE ONLY WILL BE "HIGH" OR "LOW".
boolean buttonStateLeft = LOW;            // Button states for the "Left" command
boolean lastButtonStateLeft = LOW;                
boolean currentButtonStateLeft = LOW;
boolean buttonStateRight = LOW;           // Button states for the "Right" command
boolean lastButtonStateRight = LOW;                
boolean currentButtonStateRight = LOW;
boolean buttonStateUp = LOW;              // Button states for the "Up" command
boolean lastButtonStateUp = LOW;                
boolean currentButtonStateUp = LOW;
boolean buttonStateDown = LOW;            // Button states for the "Down" command
boolean lastButtonStateDown = LOW;                
boolean currentButtonStateDown = LOW; 
boolean buttonStateEnter = LOW;           // Button states for the "Enter" command
boolean lastButtonStateEnter = LOW;                
boolean currentButtonStateEnter = LOW;
boolean buttonStateClear = LOW;           // Button states for the "Clear" command
boolean lastButtonStateClear = LOW;                
boolean currentButtonStateClear = LOW;

// DEBOUNCE VARIABLES TO MEASURE THE DEBOUNCING TIME OF A BUTTON PUSH.
// MAKE THESE "UNSIGNED LONG" VARIABLES AS THE NUMERICAL VALUE WILL HAVE AN EXTENDED SIZE.
unsigned long lastDebounceTime = 0;       // This variable takes a "snapshot" of time when any button is pushed.
unsigned long debounceDelay = 50;         // Delay time in milliseconds; the amount of time the button is pressed must be higher than the delay to register a push.


// OBJECT DECLARATION
LiquidCrystal_I2C lcd(0x27, 16, 2);   // Activates the LCD "object"



// SETUP
void setup() {

  lcd.backlight();                  // THESE COMMANDS TURN ON AND CLEAR THE LCD SCREEN
  lcd.init();
  lcd.clear();

  pinMode(leftButtonPin, INPUT);    // SETS THE leftButtonPin AS AN INPUT
  pinMode(rightButtonPin, INPUT);   // SETS THE rightButtonPin AS AN INPUT
  pinMode(upButtonPin, INPUT);      // SETS THE upButtonPin AS AN INPUT
  pinMode(downButtonPin, INPUT);    // SETS THE downButtonPin AS AN INPUT
  pinMode(enterButtonPin, INPUT);   // SETS THE enterButtonPin AS AN INPUT
  pinMode(clearButtonPin, INPUT);   // SETS THE clearButtonPin AS AN INPUT
  
  delay(1000);

}



// MAIN LOOP
void loop() {

  int unitSetting[] = {setting1Counter, setting2Counter, setting3Counter, setting4Counter, setting5Counter};    // This variable holds the individual counters in one array
  
  lcd.setCursor(0,0);                           // Menu displayed on the LCD.
  lcd.print(menuOption[directionPush]);         // The menuOption that is displayed is determined by the left or right push.
  lcd.setCursor(0,1);    
  lcd.print(unitSetting[directionPush]);        // The setting counter that is displayed is determined by the left or right push.
  lcd.setCursor(5,1);                           // This cursor setting fixes the measurementType in one place, preventing offset
  lcd.print(measurementType[directionPush]);    // by the unitSetting.

  // The program at this point is waiting for a button press.
  currentButtonStateLeft = digitalRead(leftButtonPin);          
  currentButtonStateRight = digitalRead(rightButtonPin); 
  currentButtonStateUp = digitalRead(upButtonPin);          
  currentButtonStateDown = digitalRead(downButtonPin);    
  currentButtonStateEnter = digitalRead(enterButtonPin);
  currentButtonStateClear = digitalRead(clearButtonPin);    
  
  if (currentButtonStateLeft != lastButtonStateLeft || currentButtonStateRight != lastButtonStateRight || 
  currentButtonStateUp != lastButtonStateUp || currentButtonStateDown != lastButtonStateDown || currentButtonStateEnter != lastButtonStateEnter)        
  // If there is a button push on any of the buttons, the following routine runs to check if it was a valid press:
  {
  lastDebounceTime = millis();      // lastDebounceTime is set equal to the running millis() function.
  }  

  if ((millis() - lastDebounceTime) > debounceDelay)   
  // If the lastDebounceTime (aka. the "snapshot" time) minus the running millis() function is higher than the set debounce delay, the following routine
  // below runs and checks which button was pushed: 
  {                                             

    // The current state for each button is set not equal to the pressed state and when it changes, the pressed state becomes equal to the current state.
    
    // LEFT BUTTON PRESS
    if (currentButtonStateLeft != buttonStateLeft)       // Left button scrolls the menu options to the left.  
    { 
    buttonStateLeft = currentButtonStateLeft;  
                 
      if (buttonStateLeft == LOW)                        // Once the button is released, the push is registered and the code below runs.
      {                                                 
      directionPush--;                                   // Both the up and down press counts will be reset to zero when the left button is pushed.
      upPressCount = 0;
      downPressCount = 0;
      }
          
        if (directionPush < 0)                           // If the user tries to scroll below the first menu option,
        {                                                // the program will loop back to the last menu option.
        directionPush = 4;
        }
    lcd.clear();    
    }

    // RIGHT BUTTON PRESS
    if (currentButtonStateRight != buttonStateRight)     // Right button scrolls the menu options to the right.    
    { 
    buttonStateRight = currentButtonStateRight;  
                 
      if (buttonStateRight == LOW)                         
      {                                                 
      directionPush++;            // Both the up and down press counts will be reset to zero when the right button is pushed.
      upPressCount = 0;
      downPressCount = 0;
      }
  
        if (directionPush > 4)     // If the user tries to scroll above the last menu option,
        {                          // the program will loop back to the first menu option.
        directionPush = 0;
        }
    lcd.clear();
    }

    // UP BUTTON PRESS
    if (currentButtonStateUp != buttonStateUp)      // Up button scrolls the setting upward. 
    { 
    buttonStateUp = currentButtonStateUp;  
                 
      if (buttonStateUp == LOW && directionPush == 0) //The first 5 times in which the "up" button is pushed, each push will add 1 increment to the setting.                       
      {                
      upPressCount+=1/10;     
      downPressCount = 0;                   // The downPressCount is reset to zero.    
      setting1Counter+= 1/10;

        if (upPressCount > 5)    // If the "up" button is pushed more than 5 times consecutively, the setting increment increases by 5
        {                       // with every "up" button push and resets back when the down, left or right button is pushed.
        setting1Counter = setting1Counter + 4;
        }

        if (setting1Counter > 999) // Sets the setting counter limit to 999. The user cannot increase the counter beyond 999.
        {
        setting1Counter = 999;
        }
      }  
      
      if (buttonStateUp == LOW && directionPush == 1)                         
      {            
      upPressCount++;     
      downPressCount = 0;                                             
      setting2Counter++;

        if (upPressCount > 5)
        {
        setting2Counter = setting2Counter + 4;
        }

        if (setting2Counter > 999)                       // Sets the setting counter limit to 999. The user cannot increase the counter beyond 999.
        {
        setting2Counter = 999;
        }
      }  

      if (buttonStateUp == LOW && directionPush == 2)                         
      {     
      upPressCount++;     
      downPressCount = 0;                                                     
      setting3Counter++;

        if (upPressCount > 5)
        {
        setting3Counter = setting3Counter + 4;
        }

        if (setting3Counter > 999)                       // Sets the setting counter limit to 999. The user cannot increase the counter beyond 999.
        {
        setting3Counter = 999;
        }
      }  

      if (buttonStateUp == LOW && directionPush == 3)                         
      { 
      upPressCount++;     
      downPressCount = 0;                                                         
      setting4Counter++;

        if (upPressCount > 5)
        {
        setting4Counter = setting4Counter + 4;
        }

        if (setting4Counter > 999)                       // Sets the setting counter limit to 999. The user cannot increase the counter beyond 999.
        {
        setting4Counter = 999;
        }
      }  

      if (buttonStateUp == LOW && directionPush == 4)                         
      {    
      upPressCount++;     
      downPressCount = 0;                                                      
      setting5Counter++;

        if (upPressCount > 5)
        {
        setting5Counter = setting5Counter + 4;
        }

        if (setting5Counter > 999)                       // Sets the setting counter limit to 999. The user cannot increase the counter beyond 999.
        {
        setting5Counter = 999;
        }
      }  
    lcd.clear();  
    }


    // DOWN BUTTON PRESS
    if (currentButtonStateDown != buttonStateDown)        // Down button scrolls the setting downward.
    { 
    buttonStateDown = currentButtonStateDown;  
                 
      if (buttonStateDown == LOW && directionPush == 0)   // The first 5 times in which the "down" button is pushed, each push will subtract 1 increment to the setting.                      
      {                      
      downPressCount++;
      upPressCount = 0;                                   // The upPressCount is reset to zero.
      setting1Counter--;

        if (downPressCount > 5)                           // If the "down" button is pushed more than 5 times consecutively, the setting increment decreases by 5
        {                                                 // with every "down" button push and resets back when the up, left or right button is pushed.
        setting1Counter = setting1Counter - 4;
        }

        if (setting1Counter < -999)                       // Sets the setting counter limit to -999. The user cannot increase the counter beyond -999.
        {
        setting1Counter = -999;
        }
      }  

      if (buttonStateDown == LOW && directionPush == 1)                         
      {              
      downPressCount++;
      upPressCount = 0;                                         
      setting2Counter--;

        if (downPressCount > 5)
        {
        setting2Counter = setting2Counter - 4;
        }

        if (setting2Counter < -999)                       // Sets the setting counter limit to -999. The user cannot decrease the counter beyond -999.
        {
        setting2Counter = -999;
        }
      }  

      if (buttonStateDown == LOW && directionPush == 2)                         
      {     
      downPressCount++;
      upPressCount = 0;                                                     
      setting3Counter--;

        if (downPressCount > 5)
        {
        setting3Counter = setting3Counter - 4;
        }
      
        if (setting3Counter < 0)    // This code prevents the user from entering
        {                           // a number below "0".
        setting3Counter = 0;        // Remove this code if you want to allow in
        }                           // negative numbers on a setting.    
      }  

      if (buttonStateDown == LOW && directionPush == 3)                         
      {                          
      downPressCount++;
      upPressCount = 0;                                
      setting4Counter--;

        if (downPressCount > 5)
        {
        setting4Counter = setting4Counter - 4;
        }
      
        if (setting4Counter < 0)    // This code prevents the user from entering
        {                           // a number below "0".
        setting4Counter = 0;        // Remove this code if you want to allow in
        }                           // negative numbers on a setting.
      }  

      if (buttonStateDown == LOW && directionPush == 4)                         
      {                        
      downPressCount++;
      upPressCount = 0;                                  
      setting5Counter--;

        if (downPressCount > 5)
        {
        setting5Counter = setting5Counter - 4;
        }
      
        if (setting5Counter < 0)    // This code prevents the user from entering
        {                           // a number below "0".
        setting5Counter = 0;        // Remove this code if you want to allow in
        }                           // negative numbers on a setting.
      }  
      
    lcd.clear();
    }
     
  }  


    // ENTER BUTTON PRESS
    if (currentButtonStateEnter != buttonStateEnter)        
    { 
    buttonStateEnter = currentButtonStateEnter;  
                 
      if (buttonStateEnter == LOW && directionPush == 0)      // The Enter button simply enters the setting and flashes a brief message.                         
      {                                                       // Please feel free to expand on this code to add more functions.
      lcd.clear();
      lcd.setCursor(0,0); 
      lcd.print("DEGREES FAHREN.");
      lcd.setCursor(0,1);
      lcd.print("IS ENTERED");
      delay(2000); 
      }  

      if (buttonStateEnter == LOW && directionPush == 1)                         
      {                                                       
      lcd.clear();
      lcd.setCursor(0,0); 
      lcd.print("DEGREES CELSIUS");
      lcd.setCursor(0,1);
      lcd.print("IS ENTERED");
      delay(2000);
      }  

      if (buttonStateEnter == LOW && directionPush == 2)                         
      {                                                       
      lcd.clear();
      lcd.setCursor(0,0); 
      lcd.print("WEIGHT IN LBS.");
      lcd.setCursor(0,1);
      lcd.print("IS ENTERED");
      delay(2000);
      }  

      if (buttonStateEnter == LOW && directionPush == 3)                         
      {                                                       
      lcd.clear();
      lcd.setCursor(0,0); 
      lcd.print("INCHES");
      lcd.setCursor(0,1);
      lcd.print("IS ENTERED");
      delay(2000);
      }  

      if (buttonStateEnter == LOW && directionPush == 4)                         
      {                                                       
      lcd.clear();
      lcd.setCursor(0,0); 
      lcd.print("MILES PER HOUR");
      lcd.setCursor(0,1);
      lcd.print("IS ENTERED");
      delay(2000);
      }  
    lcd.clear();
    }


    // CLEAR BUTTON PRESS
    if (currentButtonStateClear != buttonStateClear)        
    { 
    buttonStateClear = currentButtonStateClear;  
                 
      if (buttonStateClear == LOW && directionPush == 0)    // The Clear button clears all setting data depending on what menu option you are viewing.                      
      {                                                     // It flahses a brief message stating that the data has been cleared.
      lcd.clear();                                          // The press counts for both the up and down variables are also reset to zero.
      lcd.setCursor(0,0); 
      lcd.print("DEGREES FAHREN.");
      lcd.setCursor(0,1);
      lcd.print("IS CLEARED");
      setting1Counter = 0;
      downPressCount = 0;
      upPressCount = 0;
      delay(2000); 
      }  

      if (buttonStateClear == LOW && directionPush == 1)                         
      {                                                       
      lcd.clear();
      lcd.setCursor(0,0); 
      lcd.print("DEGREES CELSIUS");
      lcd.setCursor(0,1);
      lcd.print("IS CLEARED");
      setting2Counter = 0;
      downPressCount = 0;
      upPressCount = 0;
      delay(2000);
      }  

      if (buttonStateClear == LOW && directionPush == 2)                         
      {                                                       
      lcd.clear();
      lcd.setCursor(0,0); 
      lcd.print("WEIGHT IN LBS.");
      lcd.setCursor(0,1);
      lcd.print("IS CLEARED");
      setting3Counter = 0;
      downPressCount = 0;
      upPressCount = 0;
      delay(2000);
      }  

      if (buttonStateClear == LOW && directionPush == 3)                         
      {                                                       
      lcd.clear();
      lcd.setCursor(0,0); 
      lcd.print("INCHES");
      lcd.setCursor(0,1);
      lcd.print("IS CLEARED");
      setting4Counter = 0;
      downPressCount = 0;
      upPressCount = 0;
      delay(2000);
      }  

      if (buttonStateClear == LOW && directionPush == 4)                         
      {                                                       
      lcd.clear();
      lcd.setCursor(0,0); 
      lcd.print("MILES PER HOUR");
      lcd.setCursor(0,1);
      lcd.print("IS CLEARED");
      setting5Counter = 0;
      downPressCount = 0;
      upPressCount = 0;
      delay(2000);
      }  
    lcd.clear();
    }
    
  

  // After a button is pushed and the count recorded, all the states reset back to LOW for the data to be processed correctly.
  lastButtonStateLeft = currentButtonStateLeft;       // resets the left button state to LOW
  lastButtonStateRight = currentButtonStateRight;     // resets the right button state to LOW
  lastButtonStateUp = currentButtonStateUp;           // resets the up button state to LOW
  lastButtonStateDown = currentButtonStateDown;       // resets the down button state to LOW
  lastButtonStateEnter = currentButtonStateEnter;     // resets the enter button state to LOW
  lastButtonStateClear = currentButtonStateClear;     // resets the clear button state to LOW
  
}