2.2.5 Using of a rotary pulse encoderFor easier control of the menu function for the ATmega328 you can expand the circuit by a rotarypulse encoder with a push button. The circuit 2.6 shows a standard expansion for a normal characterLCD. All signals for the connection of the rotary pulse encoder are available at the plug connectorfor the LCD. For this reason the expansion can also be easy upgraded for many existing testers. Inmany cases the graphical LCD is assembled on a adapter board with some connection pins of thecharacter LCD. Also in this cases the upgrade with a rotary encoder is not very difficult to do.