What is the difference between UART?

[Carter Lee]

Posted on September 21, 2017 at 16:09

Dear all ST,

Now I'm trying to implement UART but I can't get receive all data at the time. this case need delay() to get all data..

So I've another difference way used in the same project, then it's works.

BTW, I can find the differences.

#example which is needed delay()  case .

int main(void){

////////////////////////////////////////////////////////////

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;//GPIO_PuPd_UP;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOD, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;

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

GPIO_PinAFConfig(GPIOD, GPIO_PinSource5, GPIO_AF_USART2); // USART1_TX

GPIO_PinAFConfig(GPIOC, GPIO_PinSource11, GPIO_AF_USART3); // USART1_RX

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_Init(USART3, &USART_InitStructure);USART_Cmd(USART3, ENABLE);

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_Tx;USART_Init(USART2, &USART_InitStructure);USART_Cmd(USART2, ENABLE);/////////////////////////////////////////////////////////////////////////////////NVIC_InitStructure.NVIC_IRQChannel = USART3_IRQn; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x00; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure);

USART_ITConfig(USART3, USART_IT_RXNE, ENABLE);

VS

Working good example.

int main(void)

{

RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOG, ENABLE);

RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE); RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE); //RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE); RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE); //RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3, ENABLE); RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE); RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE); GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_6;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_Init(GPIOD, &GPIO_InitStructure);GPIO_PinAFConfig(GPIOD, GPIO_PinSource5, GPIO_AF_USART2); // USART1_TXGPIO_PinAFConfig(GPIOD, GPIO_PinSource6, GPIO_AF_USART2); // USART1_RX

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_Tx | USART_Mode_Rx;USART_Init(USART2, &USART_InitStructure);USART_Cmd(USART2, ENABLE);

NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn;

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x00; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure); /* Enable USART1 Receive and Transmit interrupts */ USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);

Can you see the difference ?

What am I supposed to do to get the all data without delay at the first case?