求各路大神帮忙调下STM32F4的uart5

[凌云志轩]

#include "usart.h"
#include "stm32f4xx.h"

#define RS485tX GPIO_SetBits(GPIOE,GPIO_Pin_1);//1
#define RS485rX GPIO_ResetBits(GPIOE, GPIO_Pin_1);//0


void uart_init(void)
{
USART_InitTypeDef USART_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;

RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE);
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE);
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOE, ENABLE);

RCC_APB1PeriphClockCmd(RCC_APB1Periph_UART5, ENABLE);


GPIO_PinAFConfig(GPIOC, GPIO_PinSource12, GPIO_AF_UART5); //UART5_RX
GPIO_PinAFConfig(GPIOD, GPIO_PinSource2, GPIO_AF_UART5); //UART5_TX
GPIO_PinAFConfig(GPIOE, GPIO_PinSource1, GPIO_AF_UART5); //uart5_DE

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12;
GPIO_Init(GPIOC, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;
GPIO_Init(GPIOD, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1;
GPIO_Init(GPIOE, &GPIO_InitStructure);

USART_InitStructure.USART_BaudRate = 115200;
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_Rx | USART_Mode_Tx;
USART_Init(UART5, &USART_InitStructure);

NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
NVIC_InitStructure.NVIC_IRQChannel = UART5_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

USART_Cmd(UART5, ENABLE);
USART_ITConfig(UART5, USART_IT_RXNE, ENABLE);
}

static void delay(unsigned int dl)
{
unsigned int i,y;
for(i = 0; i < 500; i++)
{
for(y = 0; y < dl; y++);
}
}

void UART5_IRQHandler(void)
{
uint8_t x,y,z;
uint16_t checksum1,checksum2;

if(USART_GetITStatus(UART5, USART_IT_RXNE) != RESET)
{

x=USART_ReceiveData(UART5);

USART_SendData(UART5,x);

}
}

void uartsend(int ch)
{
RS_485tX;
delay(100);
while(RESET == USART_GetFlagStatus(UART5,USART_FLAG_TXE));
USART_SendData(UART5, (uint8_t) ch);
RS485rX;
delay(100);
}
用的是STM32F407的片子，现在接受和发送数据都没有，这是为什么呢？

[ycs361858643]

哥们，这个问题我刚刚解决，我的所有代码是按照你来的，出现一样问题，后来在其他论坛里面有个dma配置，然后在单独串口例程里面 做了相应修改 RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE); RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOE, ENABLE); 改成：RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC | RCC_AHB1Periph_GPIOD, ENABLE); 即可，通过mdk里面的外设可以观察前后变化，通过这样修改就搞定了

[ycs361858643]

参考的这里 https://my.st.com/public/STe2ecommunities/mcu/Lists/cortex_mx_stm32/Flat.aspx?RootFolder=/public/STe2ecommunities/mcu/Lists/cortex_mx_stm32/DMA%20Memory%20To%20UART5&FolderCTID=0x01200200770978C69A1141439FE559EB459D7580009C4E14902C3CDE46A77F0FFD06506F5B¤tviews=760