Tutorial: STM32F746 (STM32F7 Discovery) – how to turn on LED (controlling GPIO)

The first article from Tutorial: STM32F746 (STM32F7 Discovery) serie. I would like to describe how to turn on LED simply controlling GPIO. Why I began to write this tutorial and why I don’t want to use HAL or Standard Peripheral library.

Other tutorials with STM32F7:
Tutorial: STM32F746 (STM32F7 Discovery) – how to turn on/off LED by button
Tutorial: STM32F746 (STM32F7 Discovery) – how to turn on LED (controlling GPIO)
STM32F746 discovery and AC6 (System Workbench for STM32)
How to begin with STM32 and why – tutorial

These example codes can be used for another STM32F (STM32F407, STM32F103, STM32F427, STM32F746…) and STM32L (STM32L100, STM32L152, STM32L476…) with easy changes – typically atypic peripherals and change of clock source for peripherals – AHB, APB…

These codes will be written for STM32F746 with AC6 System Workbench for STM32 IDE by http://openstm32.org. But you can use these codes in another IDE e.g. Keil.

At first: Why I don’t want to use HAL or Standard Peripheral Library.

Codes write people and people do mistakes (sometimes errors). If you want to use HAL and in the code will be mistake, you have to check their codes and that’s not easy.

On the other side, If you will write own code, you know the code and structure of ARM and STM32. Yes, HAL or Standard Peripheral Library are very good functions and if you want to use it, do it. But this tutorial isn’t for you.

The tutorial will be written with finished example code which will be commented. If some code will be complicated, I will explain it on this tutorial.

Be careful, my codes can’t be always right (under all conditions). I hope that you will read datasheet and reference manual of specifically STM32 product.

main.h
</p> <p>/*</p> <p> * main.c</p> <p> *</p> <p> * Created on: 14. 8. 2015</p> <p> * Author: petus</p> <p> * Website: https://chiptron.cz</p> <p> */</p> <p>#ifndef MAIN_H_</p> <p>#define MAIN_H_</p> <p>#include “stm32f7xx.h”</p> <p>#include “stm32f746xx.h”</p> <p>#include “system_stm32f7xx.h”</p> <p>#include <stddef.h></p> <p>#include <stdio.h></p> <p>#endif /* MAIN_H_ */</p> <p></stdio.h></stddef.h>

main.c
</p> <p>/*</p> <p> * main.c</p> <p> *</p> <p> * Created on: 14. 8. 2015</p> <p> * Author: petus</p> <p> * Website: https://chiptron.cz</p> <p> */</p> <p>#include “main.h”</p> <p>int main(void)</p> <p>{</p> <p> //—-LED—-//</p> <p> RCC->AHB1ENR |= RCC_AHB1ENR_GPIOIEN; //Enable clock for PORT I</p> <p> RCC->AHB1RSTR |= RCC_AHB1RSTR_GPIOIRST; //Reset PORT I</p> <p> RCC->AHB1RSTR &= ~RCC_AHB1RSTR_GPIOIRST;</p> <p> GPIOI->MODER |= GPIO_MODER_MODER1_0; //Set mode register PIN 1, PORT I</p> <p> GPIOI->OSPEEDR |= GPIO_OSPEEDER_OSPEEDR1; //Set speed register PIN 1, PORT I</p> <p> GPIOI->ODR |= GPIO_ODR_ODR_1; //Set output data register PIN 1, PORT I</p> <p> while(1)</p> <p> {</p> <p> }</p> <p>}</p> <p>

MODERy[1:0] setting of PIN

00: PIN as input

01: PIN as output

10: Alternative function of PIN

11: Analog input

OSPEEDRy[1:0] These bits are written by software to configure the I/O output speed

00: Low speed

01: Medium speed

10: Fast speed

11: High speed

You can download project.
Other tutorials with STM32F7:
Tutorial: STM32F746 (STM32F7 Discovery) – how to turn on/off LED by button
Tutorial: STM32F746 (STM32F7 Discovery) – how to turn on LED (controlling GPIO)
STM32F746 discovery and AC6 (System Workbench for STM32)
How to begin with STM32 and why – tutorial