流水灯

功能

　　4盏灯循环点亮

分析

• 查找原理图4盏灯依次为PF6、PF9、PF10、PC0　　
• 管脚外设时钟的配置
• 管脚输出状态的配置

1. 1. 模式配置
   2. 输出类型配置
   3. 输出速率配置

• 循环打开、等待、关闭、等待操作

代码

 1 //led.h
 2 #ifndef _LED_H_
 3 #define _LED_H_
 4
 5 #define LED1_ON (GPIOF->ODR &= ~(1<<6))
 6 #define LED2_ON (GPIOF->ODR &= ~(1<<9))
 7 #define LED3_ON (GPIOF->ODR &= ~(1<<10))
 8 #define LED4_ON (GPIOC->ODR &= ~(1<<0))
 9
10 #define LED1_OFF (GPIOF->ODR |= (1<<6))
11 #define LED2_OFF (GPIOF->ODR |= (1<<9))
12 #define LED3_OFF (GPIOF->ODR |= (1<<10))
13 #define LED4_OFF (GPIOC->ODR |= (1<<0))
14
15 void led_init(int n);
16 void delay(int n);
17
18 #endif

 1 //led.c
 2 #include "stm32f4xx.h"
 3 #include "led.h"
 4
 5 void delay(int n)
 6 {
 7     while(n--);
 8 }
 9
10 void led_init(int n)
11 {
12     //管脚的外设时钟配置
13     RCC->AHB1ENR |=(1<<2);  //GPIOC外设时钟使能
14     RCC->AHB1ENR |=(1<<5);  //GPIOF外设时钟使能
15
16     //管脚输出状态配置
17     if(!n)
18     {
19         //模式配置
20         GPIOC->MODER &= ~(0X3<<(2 * n));  //清零
21         GPIOC->MODER |= (0X1<<(2 * n));   //通用输出模式
22         //输出类型配置
23         GPIOC->OTYPER &= ~(1<<n);   //推挽输出
24         //输出速率配置
25         GPIOC->OSPEEDR &= ~(0X3<<(2 * n)); //清零
26         GPIOC->OSPEEDR |= (0X2<<(2 * n));  //输出速率50M
27     }
28     else
29     {
30         //模式配置
31         GPIOF->MODER &= ~(0X3<<(2 * n));  //清零
32         GPIOF->MODER |= (0X1<<(2 * n));   //通用输出模式
33         //输出类型配置
34         GPIOF->OTYPER &= ~(1<<n);   //推挽输出
35         //输出速率配置
36         GPIOF->OSPEEDR &= ~(0X3<<(2 * n)); //清零
37         GPIOF->OSPEEDR |= (0X2<<(2 * n));  //输出速率50M
38     }
39 }

//main.c
#include "stm32f4xx.h"
#include "led.h"

int main()
{
    //PF6 PF9 PF10 PC0 状态初始化
    led_init(6);
    led_init(9);
    led_init(10);
    led_init(0);

    while(1)
    {
        LED1_ON;
        delay(1000000);
        LED1_OFF;
        delay(1000000);

        LED2_ON;
        delay(1000000);
        LED2_OFF;
        delay(1000000);

        LED3_ON;
        delay(1000000);
        LED3_OFF;
        delay(1000000);

        LED4_ON;
        delay(1000000);
        LED4_OFF;
        delay(1000000);
    }
}