STM32F103 的RS485串口问题

2019-08-14 06:23发布

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13条回答

jiutianshenjian

1楼-- · 2019-08-14 11:02

你确定usart1不是9和10，而是10和11？

xx3360765

2楼-- · 2019-08-14 15:27

/////////////usart.c
#include "stm32f10x.h"
#include "stm32f10x_gpio.h"
#include "stm32f10x_rcc.h"
#include "stm32f10x_usart.h"
#include "misc.h"
#include "usart.h"
#define RS485_DIR_TX GPIO_WriteBit(GPIOA,GPIO_Pin_9,1);
#define RS485_DIR_RX GPIO_WriteBit(GPIOA,GPIO_Pin_9,0);

void USART1_Initial(void)
{
GPIO_InitTypeDef GPIO_InitStructure2;
USART_InitTypeDef USART_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA|RCC_APB2Periph_AFIO,ENABLE);
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1,ENABLE);  //????PA,USART1?????±??

GPIO_InitStructure2.GPIO_Pin = GPIO_Pin_9 ;
  GPIO_InitStructure2.GPIO_Speed = GPIO_Speed_50MHz; //50M?±??????
  GPIO_InitStructure2.GPIO_Mode = GPIO_Mode_Out_PP; //???ì????
  GPIO_Init(GPIOA, &GPIO_InitStructure2);


  GPIO_InitStructure2.GPIO_Pin = GPIO_Pin_10;       //485_TXD
  GPIO_InitStructure2.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure2.GPIO_Mode = GPIO_Mode_AF_PP;  //???????ì????
  GPIO_Init(GPIOA, &GPIO_InitStructure2);

  GPIO_InitStructure2.GPIO_Pin = GPIO_Pin_11;          //485_RXD
  GPIO_InitStructure2.GPIO_Mode = GPIO_Mode_IN_FLOATING; //????????
  GPIO_Init(GPIOA, &GPIO_InitStructure2);

  NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;//??????????3
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3; //×???????3
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ?¨??????
NVIC_Init(&NVIC_InitStructure); //?ù?????¨????????????VIC?????÷

USART_InitStructure.USART_BaudRate = 9600;
  USART_InitStructure.USART_WordLength = USART_WordLength_8b;
  USART_InitStructure.USART_StopBits = USART_StopBits_1;
  USART_InitStructure.USART_Parity = USART_Parity_No;
  USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
  USART_InitStructure.USART_Mode = USART_Mode_Tx | USART_Mode_Rx;
  USART_Init(USART1, &USART_InitStructure);
  USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);//????????????????
USART_Cmd(USART1, ENABLE);

RS485_DIR_RX;
}

/////////////main.c
#include "gpio.h"
#include "usart.h"
#include "stm32f10x.h"
#include "stm32f10x_gpio.h"
#include "stm32f10x_rcc.h"
#include "stm32f10x_usart.h"

int main(void)
{

SystemInit();
GPIO_Initial();
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
USART1_Initial();
RS485_DIR_TX;
while(1)
{

USART_SendData(USART1, 55);

}
}