This project is just the barebones. It's an 3X4 Matrix Numpad with an 4 rows x 20 characters display and a servo (optional).

• Enable Changing the passcode while the pragram is running
• Enable the servo (only usefull for testing purposes )
• Enable the serial debug (only for test purposes or nerds :-) )

The code is pretty difficult when you don't split it into some parts:

• The variable declarations
• The initialisation of libraries
• The functions that are used by other functions
• The functions that are used in the main loop

• First we create all our variables (A lot at first but we use them all)
• Seccond we initialise all our libraries
  • The keypad library requires us to give the Keymap (Where every key is positioned), how many rows and colloms there are and where the pins are connected to
  • The LCD library requires us to give some stuff too
  • The servo library requires us to create an attribute for our new servo
• Functions:
  • The initialisation of the LCD Now to start the program we want to test if the lcd is fully functional by:
    • Enabeling, disabeling and reanabeling the backlight
    • Showing the start message on the screen
  • The ability to disable backlight afther 30 secconds
  • Getting the pressed key
  • Getting the code from user input
  • Check the code if it's correct or not
  • Open or close the lock
  • Read and write the stored code to eeprom memory
  • Getting a new code while the program is running
  • Comparing the to given codes and see if they match
• Setup:
  • Getting the eeprom code
  • When enabled initialize the servo library to attach to the servo
  • Initialize the lcd
  • When enabled initialize the Serial communication
• Main Loop:
  • Getting the keypress
  • When you are in the unlocked state and you press * the lock is going to close
  • When you are in the unlocked state and you press # the lock will enter "Change Passcode" state
  • Open the lock when the LockState in true same as Opened (Pretty straigth foreward isn't it)
  • Or getting user input to get the code.