Just a simple project using an LCD to I2C board with PCF8574 and a Grayhill 3x4 Keypad 96AB2-102-F.
If user enters correct password (12345) on keypad the LCD shows message "Good Password" and the Green Led is illuminated.
Otherwise, the message "Bad Password" is displayed on the LCD and the Red LED is illuminated.
Good for someone trying to learn keypad and LCD routines in AVR assembler.
Works on an Atmega328p with stock 1MHz clock. Tested on an Arduino UNO R3.
Can also be compiled in Atmel Studio 7.