Problems with STM32F4 serial port 4 standard library program

chenbingjy

Problems with STM32F4 serial port 4 standard library program [Copy link]

There is a board, STM32F407VET6, serial port 4 is connected to PC10 and PC11.

I wrote a program using the standard library, but it can't communicate.

The initialization code is as follows:

//IO 4

//bound:¨

void uart_init(u32 bound){

//GPIOè

GPIO_InitTypeDef GPIO_InitStructure;

USART_InitTypeDef USART_InitStructure;

NVIC_InitTypeDef NVIC_InitStructure;

RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC,ENABLE); //GPIOC±

RCC_APB2PeriphClockCmd(RCC_APB1Periph_UART4,ENABLE);//UART4±

//1

GPIO_PinAFConfig(GPIOC,GPIO_PinSource10,GPIO_AF_UART4); //GPIOC10UART4

GPIO_PinAFConfig(GPIOC,GPIO_PinSource11,GPIO_AF_UART4); //GPIOC11UART4

//USART1

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11 | GPIO_Pin_10; //GPIOC11GPIOC10

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;//

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //50MHz

GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; //ì

GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP; //-

GPIO_Init(GPIOC,&GPIO_InitStructure); //PC11PC10

//USART1 è

USART_InitStructure.USART_BaudRate = bound;//¨è

USART_InitStructure.USART_WordLength = USART_WordLength_8b;//פ8

USART_InitStructure.USART_StopBits = USART_StopBits_1;//

USART_InitStructure.USART_Parity = USART_Parity_No;//é

USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//÷

USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx; //·

USART_Init(UART4, &USART_InitStructure); //1

USART_Cmd(UART4, ENABLE); //1

USART_ClearFlag(UART4, USART_FLAG_TC);

//#if EN_USART1_RX

// USART_ITConfig(UART4, USART_IT_RXNE, ENABLE);//à

// //Usart1 NVIC

// NVIC_InitStructure.NVIC_IRQChannel = UART4_IRQn;//1¨

// NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3;//3

// NVIC_InitStructure.NVIC_IRQChannelSubPriority =3; //×3

// NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ¨

// NVIC_Init(&NVIC_InitStructure); //ù¨VIC÷

//#endif

}

At first I tried interruption, but it didn't work, then I tried querying, but it still didn't work.

Interrupt procedure:

void UART4_IRQHandler(void) //1·ò

{

u8 Res;

#if SYSTEM_SUPPORT_OS //SYSTEM_SUPPORT_OSòè§OS.

OSIntEnter();

#endif

if(USART_GetITStatus(UART4, USART_IT_RXNE) != RESET) //(±0x0d 0x0aá)

{

Res =USART_ReceiveData(UART4);//(UART4->DR); //

if((USART_RX_STA&0x8000)==0)//ê

{

if(USART_RX_STA&0x4000)//0x0d

{

if(Res!=0x0a)USART_RX_STA=0;//íó,

else USART_RX_STA|=0x8000; //ê

}

else //0X0D

{

if(Res==0x0d)USART_RX_STA|=0x4000;

else

{

USART_RX_BUF[USART_RX_STA&0X3FFF]=Nothing ;

USART_RX_STA++;

if(USART_RX_STA>(USART_REC_LEN-1))USART_RX_STA=0;//íó,

}

}

}

}

#if SYSTEM_SUPPORT_OS //SYSTEM_SUPPORT_OSòè§OS.

OSIntExit();

#endif

}

Query code:

while (USART_GetFlagStatus(UART4, USART_FLAG_RXNE) == RESET);

data=USART_ReceiveData(UART4);

Could you please tell me how to modify the code? Thanks!

chenbingjy

Someone said to use the GPIO_PinRemapConfig() function, but I don't know how to use it.
I searched on Baidu and found GPIO_PinRemapConfig(GPIO_Remap_SWJ_JTAGDisable, ENABLE);
but I still don't know how to use it. It says that PA0, PA1 are mapped to PC10, PC11.

曹伟1993

chenbingjy posted on 2019-12-7 16:29 Someone said to use the GPIO_PinRemapConfig() function, but I don't quite know how to use it. Baidu searched and found GPIO_PinRemapConfig(GPIO_ ...

The function you selected is correct, but the parameters are wrong. Your function (GPIO_PinRemapConfig(GPIO_Remap_SWJ_JTAGDisable,ENABLE); ) means "change the mapping of the specified pin GPIO_Remap_SWJ_Disable SWJ completely disable (JTAG+SW-DP)" because "After the STM32F10x series MCU is reset, PA13/14/15 & PB3/4 are configured as JTAG function by default. Sometimes in order to make full use of the resources of the MCU I/O port, we will
set these ports as normal I/O ports." The function you should use is this " GPIO_PinRemapConfig(GPIO_PartialRemap_USART4, ENABLE); "This function maps PC10 and PC11 to serial port 4 (Note: it should be added after GPIO_Init(GPIOC,&GPIO_InitStructure); )

chenbingjy

Thank you! You are right

huo_hu

/* Peripheral clock enable */
LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_UART4);

LL_AHB1_GRP1_EnableClock(LL_AHB1_GRP1_PERIPH_GPIOC);
/**UART4 GPIO Configuration
PC10 ------> UART4_TX
PC11 ------> UART4_RX
*/
GPIO_InitStruct.Pin = LL_GPIO_PIN_10|LL_GPIO_PIN_11;
GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE;
GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_VERY_HIGH;
GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
GPIO_InitStruct.Pull = LL_GPIO_PULL_UP;
GPIO_InitStruct.Alternate = LL_GPIO_AF_8;
LL_GPIO_Init(GPIOC, &GPIO_InitStruct);

USART_InitStruct.BaudRate = 115200;
USART_InitStruct.DataWidth = LL_USART_DATAWIDTH_8B;
USART_InitStruct.StopBits = LL_USART_STOPBITS_1;
USART_InitStruct.Parity = LL_USART_PARITY_NONE;
USART_InitStruct.TransferDirection = LL_USART_DIRECTION_TX_RX;
USART_InitStruct.HardwareFlowControl = LL_USART_HWCONTROL_NONE;
USART_InitStruct.OverSampling = LL_USART_OVERSAMPLING_16;
LL_USART_Init(UART4, &USART_InitStruct);
LL_USART_ConfigAsyncMode(UART4);
LL_USART_Enable(UART4);

I cut a section for you.

chenbingjy

Thanks!

huo_hu

RCC_APB2PeriphClockCmd(RCC_APB1Periph_UART4,ENABLE);//

You must have made a mistake here.

chenbingjy

Yes, just change this.