ARM按键控制灯光

uartt.c

#include "uartt.h"
char buf[51];
//初始化串口数据
void uart4_init()
{
  //1.UART4和GPIOB、GPIOG的时钟使能
  RCC->MP_AHB4ENSETR |= (0x1 << 2);  //GPIOB时钟
  RCC->MP_AHB4ENSETR |= (0x1 << 6);  //GPIOG时钟
  RCC->MP_APB1ENSETR |= (0x1 << 16); //UART4时钟
  RCC->MP_APB1ENSETR |= (0x3 << 4);
  //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 << 28));
  USART4->CR1 &= (~(0x1 << 12));
  //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) << 0);
  //9.设置波特率为115208bps
  USART4->BRR = 0x22B;
  //10.发送器、接收器使能
  USART4->CR1 |= (0x1 << 3); //发送
  USART4->CR1 |= (0x1 << 2); //接收
  //11.串口使能
  USART4->CR1 |= (0x1 << 0);
  // 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));
}
//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)))
    ;
  USART4->TDR = i;
  //2.阻塞等待数据传输完成，函数返回
  while (!(USART4->ISR & (0x1 << 6)))
    ;
}
//
char mygetchar()
{
  char a;
  //判断RDR寄存器是否有就绪的数据，如果有就读取,否则等待
  while (!(USART4->ISR & (0x1 << 5)))
    ;
  a = USART4->RDR;
  return a;
}

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));
}

main.c

#include "uartt.h"

void delay(int ms)

{

	int i, j;

	for (i = 0; i < ms; i++)

	{

		for (j = 0; j < 2000; j++)

			;

	}

}

int main()

{

	//1.串口的初始化

	uart4_init();

	char a;

	//char *str;

	//现象是发送一个a串口工具打印一个b

	while (1)

	{

		myputchar('\n');

		myputchar('\r');

		//2.从串口读取一个字符

		a = mygetchar();

		switch (a)

		{

		case 'a':

			led1_on();

			break;

		case 'b':

			led2_on();

			break;

		case 'c':

			led3_on();

			break;

		case 'e':

			led1_off();

			break;

		case 'f':

			led2_off();

			break;

		case 'g':

			led3_off();

			break;

		}

		//3.将读取到的字符发送回去

		myputchar(a);

	}



	return 0;

}

uartt.h

#ifndef __UARTTT_H__
#define __UARTTT_H__
#include "stm32mp1xx_gpio.h"
#include "stm32mp1xx_rcc.h"
#include "stm32mp1xx_uart.h"

//初始化串口数据
void uart4_init();
void myputchar(char i);
char mygetchar();
void led1_on();
void led2_on();
void led3_on();
void led1_off();
void led2_off();
void led3_off();

#endif