In fact, it's only slightly larger than Arduino's smallest board, the Nano ... from basic LEDs and buzzers to more sophisticated LCD and Wi-Fi modules. [Featured image by Raspberry Pi Foundation ...

The system triggers an alert via a buzzer and LED and displays the reminder on an LCD screen. The schedule is controlled via a mobile app using Blynk.

Arduino is an I2C communication application. In this application, I2C communication takes place between the Arduino and the MCP23017 integrated circuit.