How to Use Interrupts in STM32F103C8

This smart pill dispenser project utilizes an STM32F103C8T6 microcontroller, commonly known as the STM32 Blue Pill, to manage event-driven tasks using external interrupts. In a typical embedded application like an assistive medical device, the system must remain ready to respond instantly to user inputs without getting bogged down in repetitive polling loops. Here, a push button connected with a 10K pull-down resistor serves as the external trigger. When the button is pressed, it applies a high logic level to the designated interrupt pin on the STM32F103C8, instantly halting the main program execution to jump directly to an Interrupt Service Routine (ISR). Inside this ISR, the system registers the button press event and toggles the state of an LED. Simultaneously, status updates and user feedback are continuously managed and rendered onto a 16x2 LCD display driven via the Arduino IDE and the LiquidCrystal library. Because the STM32 operates on 3.3V logic, the external circuit components must be carefully wired to prevent any overvoltage conditions on the microcontroller pins. By leveraging hardware interrupts rather than continuous software polling, the microcontroller efficiently allocates its processing cycles, ensuring that critical user interface interactions and real-time events are handled instantly and reliably.