This project is a summary of some laboratories on AVR microcontrollers made during my studies. The schematics file was created with KiCad. This project should have 6 or 7 different functional parts. On the laboratories we were learning how to use ports, counters, LCD display and all of the tasks should work. I would like to implement some more functionality to switch between the tasks with the keyboard and display the task number and description on the LCD. Description of each lab: lab1: sequential LED turn on/off - 3 different types of implementation: a) moving a bit in the registry. b) multiplication of a bit (or division). c) bit rotation in the registry. lab2: sequential LED turn on/off - using table. lab3: sequential LED turn on/off and changing direction after key press - using external interrupt. lab4: using 8-bit timer/counter to count time between turning on/off the LEDs. lab5: using PWM mode of the timer/counter and show it on the LED or LCD display backlight. lab6: usage of the LCD display (HD44780 compatibile). Almost each task for the lab is based on the previous one. Difference between the implemented solution and on the lab is that there is a core program that manages all the tasks and handles the keyboard and display. The 6 tasks differ only in certain parts of the code, where some tasks are already handled by the main program.