Published January 3, 2026 © MIT

Blinking LED Magic with STM32 - Bare-Metal

This project blinks an LED on an STM32 microcontroller using pure bare-metal programming by directly configuring registers.

ExpertFull instructions provided1 hour107

Blinking LED Magic with STM32 - Bare-Metal

Things used in this project

Hardware components

STMicroelectronics STM32F7 Series

Software apps and online services

STMicroelectronics STM32CubIDE

Hand tools and fabrication machines

STMicroelectronics STLink

Story

IntroductionIn this bare-metal STM32 project, we blink an LED connected in current-sinking configuration on a custom board — no libraries, just direct register access!The LED anode is connected to VCC (3.3V) through a current-limiting resistor, and the cathode is tied to PF2. This common setup lets the GPIO pin control the LED by sinking current when pulled low.Perfect for learning low-level GPIO control on custom hardware.

Parts Needed

Custom STM32 board (your own design with GPIOF access)
One LED
220–330 Ω resistor (connected between VCC and LED anode)
Programmer (ST-Link or similar)
Bare-metal development environment

Circuit Connection

LED anode → resistor → VCC (3.3V)
LED cathode → PF2
No pull-up needed

Code

LED blanking Bare-Metal library

#include "stm32g474xx.h"

void delay(volatile uint32_t t)
{
    while(t--);
}

int main(void)
{
    /* Enable GPIOF clock */
    RCC->AHB2ENR |= RCC_AHB2ENR_GPIOFEN;

    /* PF2 output */
    GPIOF->MODER &= ~(3U << (2 * 2));
    GPIOF->MODER |=  (1U << (2 * 2));

    /* Push-pull */
    GPIOF->OTYPER &= ~(1U << 2);

    /* LED OFF initially (PF2 = 1) */
    GPIOF->BSRR = ~(1U << 2);

    while (1)
    {
        /* LED ON (PF2 = 0) */
        GPIOF->BSRR = (1U << (2 + 16));
        delay(800000);

        /* LED OFF (PF2 = 1) */
        GPIOF->BSRR = (1U << 2);
        delay(800000);
    }
}

Credits

Mohammad Nabidoust

9 projects • 4 followers

STM32xx projects Design, Circuit PCB Design, Medical, Industrial, Power supply

Blinking LED Magic with STM32 - Bare-Metal

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Schematics

Schematic

Code

LED blanking Bare-Metal library

Credits

Mohammad Nabidoust

Comments

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Blinking LED Magic with STM32 - Bare-Metal

Blinking LED Magic with STM32 - Bare-Metal

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Schematics

Schematic

Code

LED blanking Bare-Metal library

Credits

Mohammad Nabidoust

Comments

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