By Emanuele Signoretta on January 18, 2021
This is an user friendly tiny digital table clock where user can access all basic functions of clocks including setting alarms, viewing temperature, viewing date, setting date and time, etc. It has a buzzer for alarm and four push buttons (Menu, Left, Right, Cancel) for user interaction. It can be powered by a standard micro USB cable.
Its user interface is very simple. User can enter menu and then change the clock parameters (time, date, month, year, alarm, etc). The alarm parameters are stored in EEPROM of ATmega 328p so it dosen’t forget alarm even if the power cuts. Each and every part of clock is detachable as shown in figure. It also comes with serial UART interface headers for any future firmware upgrade.
ATmega328p provides 20 GPIOs (14 digital and 6 analog) but as we are using seven segment displays we will be requiring 28 (7*4) pins only for seven segment display alone. To avoid this issue we will be taking advantage of persistence of vision of human eye which I will discuss in later section.