STM32 External Interrupt (Button - LED Toggle)

This project demonstrates how to use an External Interrupt (EXTI) to control an LED using a push button on the STM32F446RE Nucleo board.

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⚙️ Description

• When the user button (PC13) is pressed, it triggers an EXTI interrupt.
• Inside the interrupt handler, the LED (PA5) toggles its state.
• The LED remains in its toggled state until the next button press.
• The project is developed using STM32CubeIDE and HAL libraries.

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🧰 Hardware Setup

Pin	Function	Description
PC13	Input	User button (EXTI)
PA5	Output	LED (active HIGH)

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🧩 Key Files

File	Description
main.c	Initializes GPIO and configures EXTI
stm32f4xx_it.c	Handles the interrupt (toggles LED)
main.h	Header file for main source
stm32f4xx_it.h	Interrupt declarations
STM32_Button_LED_Interrupt.ioc	Pin & clock configuration file

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🚀 How to Build and Run

1. Open the project in STM32CubeIDE.
2. Connect your Nucleo STM32F446RE board.
3. Build → Debug → Run.
4. Press the blue USER button → observe LED toggle (PA5).

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🧾 License

This project follows the STMicroelectronics software license included in the LICENSE file.

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🧠 Bonus Tip

You can add software debounce by adding a small delay inside the interrupt handler, or better — use a timer-based debounce to make it more reliable.