It demonstrate how to work with 20x4 backlighted LCD and how to write on it, custom chars generation, too. Buzzer on PWM, LED on digital out, potentiometer as analog input, and switch as digital input, with debouncing via interrupt.

My first work with Arduino. With this i learned to use many components. I use an LCD 20x4 16 pin with parallel input (not the serial one). Be aware, some LCD board have the backlight pins inverted, so check your datasheet or silk plane to know how to connect, or you can damage LCD board. Begin soldering the pin strip on back of LCD in order to place in the breadboard. Continue with components and wires as described. Connect USB to the computer and load the sketch (2 files, same sketch). You will hear 3 beep. A 5 secs timer will start, you have time to move potenziometer to a random position, that will be considered as 100%. After the setup a 3 beep sound will occur again and you will see: - a counter with the number of clic on the switch, the state of buzzer (swapped by the switch), - a percent indicates how the potentiometer is rotated, - a proportional bar at potentiometer angle and - a on fourth line with the hour, minutes, seconds and milliseconds from reset time.

Sorry for my english and have good time with my project. Angelo__