2.串口发送指令控制硬件工作
结果：
uart.h
#ifndef __UART_H__
#define __UART_H__
#include "stm32mp1xx_gpio.h"
#include "stm32mp1xx_rcc.h"
#include "stm32mp1xx_uart.h"void myuart4_init();
void myputchar(char i);
char mygetchar();
char *mygets();
void myputs(char *s);
void all_led_init();
void led1_on();
void led2_on();
void led3_on();
void led1_off();
void led2_off();
void led3_off();int mystrcmp(char *ptr,char *str);
#endifuart.c
#include "myuart.h"
char buf[100]={0};//串口数据初始化
void myuart4_init()
{//1.UART4和GPIOB\GPIOG的时钟使能RCC->MP_AHB4ENSETR |= (0x1<<1);//使能GPIOB时钟RCC->MP_AHB4ENSETR |= (0x1<<6);//使能GPIOG时钟RCC->MP_APB1ENSETR |= (0X1<<16);//使能UART4时钟//2.设置PB2和PG11的管脚复用GPIOB->MODER&= (~(0x3<<4));GPIOB->MODER|= (0x2<<4); //设置复用GPIOB->AFRL &= (~(0XF<<8));GPIOB->AFRL |= (0X8<<8);//设置uart4功能复用GPIOG->MODER&= (~(0x3<<22));GPIOG->MODER|= (0x2<<22); //设置复用GPIOG->AFRH &= (~(0XF<<12));GPIOG->AFRH |= (0X6<<12);//设置uart4功能复用//3.先去设置串口禁用，方便设置数据格式USART4->CR1 &= (~0X1);//4.设置8位数据位USART4->CR1 &=(~(0x1<<12));USART4->CR1 &=(~(0x1<<28));//5.设置没有奇偶校验USART4->CR1 &=(~(0x1<<10));//6.设置16倍采样 USART4->CR1 &=(~(0x1<<15));//7.设置1位停止位USART4->CR2 &=(~(0x3<<12));//8.设置1分频USART4->PRESC&=(~0xf);//9.设置波特率为115200bpsUSART4->BRR=0x22B;//10.发送器、接收器使能USART4->CR1|=(0X1<<3);USART4->CR1|=(0X1<<2);//11.串口使能USART4->CR1|=(0X1);}
//封装函数发送一个字符数据void myputchar(char i)
{//1.判断TDR寄存器是否为空，如果为空，向TDR寄存器写入数据while(((USART4->ISR)&(0x1<<7))==0);USART4->TDR=i;//2.阻塞等待数据传输完成，函数返回while(((USART4->ISR)&(0x1<<6))==0);}char mygetchar()
{//判断RDR寄存器是否有就绪的数据，如果有就读取，否则等待char a;while(((USART4->ISR)&(0x1<<5))==0);a=USART4->RDR;return a;
}void myputs(char *s)
{while(*s){myputchar(*s);s++;}myputchar('\n');//切换到下一行myputchar('\r');//切换到一行的开头
}char *mygets()
{unsigned int i=0;for(i=0;i<100;i++){buf[i]=mygetchar();myputchar(buf[i]);if(buf[i]=='\r')break;}buf[i]='\0';myputchar('\n');return buf;
}void all_led_init()
{//1.使能外设时钟
RCC->MP_AHB4ENSETR |= (0x3<<4);//2.设置PF10 PE10 PE8为输出输出GPIOE->MODER&= (~(0x3<<20));GPIOE->MODER|= (0x1<<20);GPIOF->MODER&= (~(0x3<<20));GPIOF->MODER|= (0x1<<20);
GPIOE->MODER &= (~(0x3<<16));
GPIOE->MODER|= (0x1<<16);//3.设置推挽输出
GPIOE->OTYPER &= (~(0x1<<10));
GPIOF->OTYPER &= (~(0x1<<10));GPIOE->OTYPER &= (~(0x1<<8));//4.设置输出速度为低速
GPIOE->OSPEEDR &= (~(0x3<<20));
GPIOF->OSPEEDR &= (~(0x3<<20));GPIOE->OSPEEDR &= (~(0x3<<16));
//5.设置无上拉下拉
GPIOE->PUPDR &= (~(0x3<<20));
GPIOF->PUPDR &= (~(0x3<<20));
GPIOE->PUPDR &= (~(0x3<<16));
}void led1_on()
{GPIOE->ODR |= (0x1<<10);}
void led2_on()
{
GPIOF->ODR |= (0x1<<10);}
void led3_on()
{GPIOE->ODR |= (0x1<<8);}void led1_off()
{
GPIOE->ODR&= (~(0x1<<10));}
void led2_off()
{GPIOF->ODR &= (~(0x1<<10));}
void led3_off()
{GPIOE->ODR &= (~(0x1<<8));}int mystrcmp(char *ptr,char *str)
{while(*ptr){if(*ptr!=*str)return -1;ptr++;str++;}return 0;
}
main.c
#include "myuart.h"int main(){myuart4_init();all_led_init();char *buf;while(1){ myputchar('\n');myputchar('\r');buf=mygets();if(mystrcmp(buf,"led1_on")==0)led1_on();else if(mystrcmp(buf,"led1_off")==0)led1_off();else if(!mystrcmp(buf,"led2_on"))led2_on(); else if(!mystrcmp(buf,"led2_off"))led2_off();else if(mystrcmp(buf,"led3_on")==0)led3_on();else if(mystrcmp(buf,"led3_off")==0)led3_off();}return 0;}
