25.1.3 UART串口通信

1.FSMP1A开发板进行串口通信实验：

功能：电脑输入LED_ON点亮扩展版LED灯，输入LED_OFF熄灭扩展版LED灯

代码实现：

uart4.c

#include "uart4.h"
//串口初始化
void uart4_init(){//使能UART4外设时钟RCC->MP_APB1ENSETR |=(0X1<<16);//使能GPIOB/GPIOG外设时钟RCC->MP_AHB4ENSETR |=(0X1<<1);RCC->MP_AHB4ENSETR |=(0X1<<6);//设置PB2/PG11复用为UART4功能//PB2GPIOB->MODER &=(~(0X3<<4));//先清零GPIOB->MODER |=(0X2<<4);//设置成复用模式GPIOB->AFRL &=(~(0XF<<8));//先清零GPIOB->AFRL |=(0X8<<8);//设置成UART4-RX模式//PG11GPIOG->MODER &=(~(0X3<<22));//先清零GPIOG->MODER |=(0X2<<22);//设置成复用模式GPIOG->AFRH &=(~(0xF<<12));//先清零GPIOG->AFRH |=(0X6<<12);//设置成UART4-TX模式//禁用串口UE=0，因为其他相关设置是在UE=0情况下设置的USART4->CR1 &=(~(0X1<<0));//设置8bit数据位USART4->CR1 &=(~(0X1<<12));USART4->CR1 &=(~(0X1<<28));//设置没有校验位USART4->CR1 &=(~(0X1<<10));//设置不分频USART4->PRESC &=(~(0XF<<0));//设置16倍过采样USART4->CR1 &=(~(0X1<<15));//设置1bit停止位USART4->CR2 &=(~(0X3<<12));//设置115200波特率USART4->BRR=0X22B;//使能发送器USART4->CR1 |=(0X1<<3);//使能接收器USART4->CR1 |=(0X1<<2);//使能串口USART4->CR1 |=0X1;
}//封装单个字符发送函数
void putchar(char ch){//判断发送数据寄存器是否为空，不为空则等待while(!(USART4->ISR&(0X1<<7)));//为空，向发送数据寄存器写入数据USART4->TDR=ch;//等待发送完成while(!(USART4->ISR&(0x1<<6)));
}//单个字符的接收
char getchar(){//判断接收数据寄存器是否有数据//没有数据则等待while(!(USART4->ISR&(0X1<<5)));//有数据就将数据读取返回放置内存中变量return USART4->RDR;
}//封装字符串的输入
void gets(char *s)
{//循环调用单个字符接收//等待读取到回车键\r，字符串接收while(1){*s=getchar();if((*s)=='\r'){break;}putchar(*s);//让输入的字符串回显到电脑串口工具s++;}*s='\0';putchar('\n');putchar('\r');
}//字符串输出
void puts(char *s)
{//循环调用单个字符的发送//直到遇到\0结束while(*s){putchar(*s);s++;}putchar('\0');//最后末尾发送一个换行一个回车putchar('\n');putchar('\r');
}//自定义strcmp函数
int my_strcmp(const char *des,const char *src){while(*des==*src){if(*des=='\0'||*src=='\0'){break;}des++;src++;}return *des-*src;
}

uart.h

#ifndef __UART4__H__
#define __UART4_H__
#include "stm32mp1xx_gpio.h"
#include "stm32mp1xx_rcc.h"
#include "stm32mp1xx_uart.h"
void uart4_init();
void putchar(char ch);
char getchar();
void gets(char *s);
void puts(char *s);
int my_strcmp(const char *des,const char *src);#endif

led.c

#include "led.h"
//初始化LED1-3所对应的GPIO引脚以及使能
void led_init(){//GPIO初始化//将RCC_MP_AHB4ENSETR寄存器第[5:4]位设置为1，使能GPIOE和F外设时钟RCC->MP_AHB4ENSETR |=(0X3<<4);//1.GPIOE_MODER[21:20]设置为01，PE10管教为输出模式GPIOE->MODER &=(~(0x3<<20));//先清零GPIOE->MODER |=(0x1<<20); //再置位//1.GPIOF_MODER[21:20]设置为01，PF10管教为输出模式GPIOF->MODER &=(~(0x3<<20));//先清零GPIOF->MODER |=(0x1<<20); //再置位//1.GPIOE_MODER[17:16]设置为01，PE8管教为输出模式GPIOE->MODER &=(~(0x3<<16));//先清零GPIOE->MODER |=(0x1<<16); //再置位//2.GPIOE_OTYPER[10]设置为0，PE10管脚推挽输出GPIOE->OTYPER &=(~(0x1<<10));//先清零//2.GPIOF_OTYPER[10]设置为0，PF10管脚推挽输出GPIOF->OTYPER &=(~(0x1<<10));//先清零//2.GPIOE_OTYPER[8]设置为0，PE8管脚推挽输出GPIOE->OTYPER &=(~(0x1<<8));//先清零//3.GPIOE_OSPEEDR[21:20]设置为00，PE10管脚为低速输出GPIOE->OSPEEDR &=(~(0x3<<20));//先清零//3.GPIOF_OSPEEDR[21:20]设置为00，PF10管脚为低速输出GPIOF->OSPEEDR &=(~(0x3<<20));//先清零//3.GPIOE_OSPEEDR[17:16]设置为00，PE8管脚为低速输出GPIOE->OSPEEDR &=(~(0x3<<16));//先清零//4.GPIOE_PUPDR[21:20]设置为00，PE10管脚无上拉下拉电阻GPIOE->PUPDR &=(~(0x3<<20));//先清零//4.GPIOF_PUPDR[21:20]设置为00，PF10管脚无上拉下拉电阻GPIOF->PUPDR &=(~(0x3<<20));//先清零//4.GPIOE_PUPDR[17:16]设置为00，PE8管脚无上拉下拉电阻GPIOE->PUPDR &=(~(0x3<<16));//先清零}
//对引脚和哪盏灯控制，参数1：确定哪盏灯，参数2：确定开灯为1，关灯为0
void led_ctl(int which,int cmd){switch(which){case 1:if(cmd==0)//关灯GPIOE->ODR &=(~(0x1<<10));else if(cmd==1)//开灯GPIOE->ODR |=(0x1<<10); break;case 2:if(cmd==0)//关灯GPIOF->ODR &=(~(0x1<<10));else if(cmd==1)//开灯GPIOF->ODR |=(0x1<<10); break;case 3:if(cmd==0)//关灯GPIOE->ODR &=(~(0x1<<8));else if(cmd==1)//开灯GPIOE->ODR |=(0x1<<8); break;}
}

led.h

#ifndef __LED__
#define __LED__
#include "stm32mp1xx_gpio.h"
#include "stm32mp1xx_rcc.h"
#include "stm32mp1xx_uart.h"
/* typedef struct{ */
/*     unsigned int MODER; */
/*     unsigned int OTYPER; */
/*     unsigned int OSPEEDR; */
/*     unsigned int PUPDR; */
/*     unsigned int IDR; */
/*     unsigned int ODR; */
/*     unsigned int BSRR; */
/* }gpio_t; */
/*  */
/* #define GPIOE (*(gpio_t*)0x50006000) */
/* #define GPIOF (*(gpio_t*)0x50007000) */
/* #define RCC (*(unsigned int*)0x50000A28) */void led_init();void led_ctl(int which,int cmd);#endif

main.c

#include "uart4.h"
#include "led.h"int main()
{uart4_init();//uart4串口初始化led_init();//led1-3初始化/* char ch; *//* //电脑端发送数据，接收数据 *//* while(1){ *//* 	//读取电脑发送的字符 *//* 	ch=getchar(); *//* 	//将字符+1后返回给电脑 *//* 	putchar(ch+1); *//* 	putchar('\n');//换行 *//* 	putchar('\r');//回车 *//* 	 *//* } */char buf[128];//定义一个字符数组while(1){gets(buf);puts(buf);if(my_strcmp(buf,"LED1_ON")==0){led_ctl(1,1);}if(my_strcmp(buf,"LED1_OFF")==0){led_ctl(1,0);	}if(my_strcmp(buf,"LED2_ON")==0){led_ctl(2,1);}if(my_strcmp(buf,"LED2_OFF")==0){led_ctl(2,0);	}if(my_strcmp(buf,"LED3_ON")==0){led_ctl(3,1);}if(my_strcmp(buf,"LED3_OFF")==0){led_ctl(3,0);	}}return 0;
}

2.stm32U5开发板进行串口通信实验：

功能：电脑输入LED_ON点亮扩展版LED灯，输入LED_OFF熄灭扩展版LED灯

 main.c

int main(void)
{/* USER CODE BEGIN 1 *//* USER CODE END 1 *//* MCU Configuration--------------------------------------------------------*//* Reset of all peripherals, Initializes the Flash interface and the Systick. */HAL_Init();/* USER CODE BEGIN Init *//* USER CODE END Init *//* Configure the system clock */SystemClock_Config();/* Configure the System Power */SystemPower_Config();/* USER CODE BEGIN SysInit *//* USER CODE END SysInit *//* Initialize all configured peripherals */MX_GPIO_Init();MX_ICACHE_Init();MX_USART1_UART_Init();/* USER CODE BEGIN 2 *//* USER CODE END 2 *//* Infinite loop *//* USER CODE BEGIN WHILE */char buf[32];//保存串口数据收发的容器while (1){memset(buf,0,sizeof(buf));//进行数组清空HAL_UART_Receive(&huart1,(uint8_t *)buf,30,10000); //阻塞接收 if(strcmp(buf,"LED1_ON")==0){//打开led1HAL_GPIO_WritePin(GPIOC,GPIO_PIN_4,GPIO_PIN_SET);}if(strcmp(buf,"LED3_ON")==0){//打开led3HAL_GPIO_WritePin(GPIOC,GPIO_PIN_13,GPIO_PIN_SET);}if(strcmp(buf,"LED_CYTLE_ON")==0){//循环打开HAL_GPIO_WritePin(GPIOC,GPIO_PIN_4,GPIO_PIN_SET);HAL_GPIO_WritePin(GPIOC,GPIO_PIN_13,GPIO_PIN_RESET);HAL_Delay(1000);HAL_GPIO_WritePin(GPIOC,GPIO_PIN_4,GPIO_PIN_RESET);HAL_GPIO_WritePin(GPIOC,GPIO_PIN_13,GPIO_PIN_SET);HAL_Delay(1000);}if(strcmp(buf,"LED1_OFF")==0){//关闭led1HAL_GPIO_WritePin(GPIOC,GPIO_PIN_4,GPIO_PIN_RESET);}if(strcmp(buf,"LED3_OFF")==0){//关闭led3HAL_GPIO_WritePin(GPIOC,GPIO_PIN_13,GPIO_PIN_RESET);}if(strcmp(buf,"LED_CYTLE_OFF")==0){//关闭循环HAL_GPIO_WritePin(GPIOC,GPIO_PIN_4,GPIO_PIN_RESET);HAL_GPIO_WritePin(GPIOC,GPIO_PIN_13,GPIO_PIN_RESET);}if(strcmp(buf,"FAN_ON")==0){//打开风扇HAL_GPIO_WritePin(GPIOC,GPIO_PIN_6,GPIO_PIN_SET);}if(strcmp(buf,"FAN_OFF")==0){//关闭风扇HAL_GPIO_WritePin(GPIOC,GPIO_PIN_6,GPIO_PIN_RESET);}if(strcmp(buf,"FENGMING_ON")==0){//打开蜂鸣器HAL_GPIO_WritePin(GPIOC,GPIO_PIN_7,GPIO_PIN_SET);}if(strcmp(buf,"FENGMING_OFF")==0){//关闭蜂鸣器HAL_GPIO_WritePin(GPIOC,GPIO_PIN_7,GPIO_PIN_RESET);}HAL_UART_Transmit(&huart1,(uint8_t *)buf,sizeof(buf),5);/* USER CODE END WHILE *//* USER CODE BEGIN 3 */}/* USER CODE END 3 */
}