STM32 lighting procedure

STM32- Lighting procedure

Recently learned to use STM32, Make a note .
Rigid contact , Let's start with the lighting procedure . MCU lighting program , It's equivalent to learning language hello world Procedure .

First, let's briefly introduce the development environment , The chip type is STM32F030C8, The integrated development environment uses Keil5 MDK-ARM, Simulator use JLINK.

Light the light , First determine the pin connecting the lamp . On my board is PA0 The next one led The lamp .
In the program , Namely GPIO_Pin_0 了 . For scalability , Or say , For the convenience of modifying pins , I used a function to encapsulate . as follows ：

int get_gpios(){    
    return GPIO_Pin_0 ;// Connected to the lamp gpio Pin , There can be multiple         
}

Light the light , That is, set this pin to output , And control its high and low levels . Let's set the initialization first ：

void LED_Init(void)
{

  GPIO_InitTypeDef  GPIO_InitStructure;
  
  /* Can make GPIOA The clock */  
  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);

  /* To configure LED Corresponding pins PA1*/
  GPIO_InitStructure.GPIO_Pin = get_gpios();
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init(GPIOA, &GPIO_InitStructure);
    
  GPIOA->BSRR = get_gpios() ;// Lights up         
}

The specific realization of flashing , I also wrote a function , Convenient to call later ：

int flag_led_on=0;

void LED_toggle(){    
    flag_led_on = 1 - flag_led_on;    
    if(flag_led_on!=0){
        GPIOA->BRR = get_gpios() ;     //reset
    } else {
        GPIOA->BSRR = get_gpios() ;    //set
    }        
}

 

such , The main function is completed , The rest is to call in the main loop .
The main function is very simple ：

int main(void)
{

    LED_Init();// Lamp initialization
        
    while(1){
        Delay(1600000);// Time delay 1s
        LED_toggle(); //LED Flip
    }

}

Here is a new function ：Delay(), Is a delay function . To simplify the code , So the delay function does not use a timer , It's a simple cycle of waiting . as follows ：

void Delay(uint32_t nCount) 
{
     for(; nCount != 0; nCount--);
}

thus , This lighting procedure is completed , Is it simple .

in addition , Briefly explain why the delay function is used 1600000 Is the parameter .
I passed the experiment , It is found that the time set to this value is basically 1s.
however , On different boards , The program is optimized differently , Or the writing method of delay code is different , Will lead to the difference of delay time . The specific value can be adjusted according to the actual operation .

in the future , I will carefully analyze the reason of this value .

This demo Project code for , You can get it from the following address ：

https://download.csdn.net/download/lintax/10734630