我遇到一个奇怪的问题。我有一块带有2个UART接口（STM32F217）的板，并且我正在使用DMA接收两个UART（USART1和USART2）上的数据。
USART2完美运行。我可以通过它发送和接收数据，没有问题，但是USART1出现了问题。它仅在第一次传输时正常工作。如果它只工作了一次然后停止了，那我就没事了，因为这可能意味着我只需要添加USART1中断函数并调用其IRQHandler即可。但是我的问题是下次接收数据时，它会掉落前几个字节（随机...有时会掉2个，有时会掉到6个字节，这不像它是一种快速协议，它的超时时间为1s）。
这是我的工作流程： -初始化UART；
致电Receive_DMA;
协议的大小可变，取决于前几个字节，因此我配置了固定的256个循环接收传输（报头+数据的最大大小），并检查到目前为止已接收了多少个字节（如果数量与第一个字节就可以了。
出现错误（未收到完整的数据包，错误的CRC或超时）或成功后，请致电
HAL_UART_DMAStop（＆huart1）;
然后
if(HAL_UART_Receive_DMA(&huart1, rx232buffer, 256) != HAL_OK) {
while(1);
}
这对于两个UART都可以完成，一个可以完美地工作，另一个可以很好地工作，然后开始丢弃字节。
有什么问题的想法吗？
编辑
这是我的代码的一个版本。我刚刚编写了该功能（在主循环内……不完全是，但它的工作原理与此相似……我的代码有点大，并且有很多与通讯无关的东西，所以我只是这样重写了它……如前所述huart1只能正常工作一次，然后丢弃字节... huart2可以正常工作.. huart1是RS232 ... huart2 i RS485）
static void rxbuffer[256] = {0};
static void rx232buffer[256] = {0};
struct header {
int startWord;
int command;
int size;
};
UART_HandleTypeDef huart1;
UART_HandleTypeDef huart2;
DMA_HandleTypeDef hdma_usart1_rx;
DMA_HandleTypeDef hdma_usart1_tx;
DMA_HandleTypeDef hdma_usart2_rx;
DMA_HandleTypeDef hdma_usart2_tx;
static void MX_DMA_Init(void)
{
/* DMA controller clock enable */
__HAL_RCC_DMA2_CLK_ENABLE();
__HAL_RCC_DMA1_CLK_ENABLE();
/* DMA interrupt init */
/* DMA1_Stream5_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMA1_Stream5_IRQn, 5, 0);
HAL_NVIC_EnableIRQ(DMA1_Stream5_IRQn);
/* DMA1_Stream6_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMA1_Stream6_IRQn, 5, 0);
HAL_NVIC_EnableIRQ(DMA1_Stream6_IRQn);
/* DMA2_Stream2_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMA2_Stream2_IRQn, 5, 0);
HAL_NVIC_EnableIRQ(DMA2_Stream2_IRQn);
/* DMA2_Stream7_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMA2_Stream7_IRQn, 5, 0);
HAL_NVIC_EnableIRQ(DMA2_Stream7_IRQn);
}
static void MX_USART1_UART_Init(void)
{
huart1.Instance = USART1;
huart1.Init.BaudRate = 57600;
huart1.Init.WordLength = UART_WORDLENGTH_8B;
huart1.Init.StopBits = UART_STOPBITS_1;
huart1.Init.Parity = UART_PARITY_NONE;
huart1.Init.Mode = UART_MODE_TX_RX;
huart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;
huart1.Init.OverSampling = UART_OVERSAMPLING_16;
if (HAL_UART_Init(&huart1) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
}
static void MX_USART2_UART_Init(void)
{
huart2.Instance = USART2;
huart2.Init.BaudRate = 57600;
huart2.Init.WordLength = UART_WORDLENGTH_8B;
huart2.Init.StopBits = UART_STOPBITS_1;
huart2.Init.Parity = UART_PARITY_NONE;
huart2.Init.Mode = UART_MODE_TX_RX;
huart2.Init.HwFlowCtl = UART_HWCONTROL_NONE;
huart2.Init.OverSampling = UART_OVERSAMPLING_16;
if (HAL_UART_Init(&huart2) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
}
int main(void)
{
int bytecount;
int bytecount232;
int rxlen485;
int rxlen232;
HAL_Init();
SystemClock_Config();
MX_GPIO_Init();
MX_DMA_Init();
MX_USART1_UART_Init();
MX_USART2_UART_Init();
if(HAL_UART_Receive_DMA(&huart2, rxbuffer, 256) != HAL_OK) {
while(1);
}
if(HAL_UART_Receive_DMA(&huart1, rx232buffer, 256) != HAL_OK) {
while(1);
}
while(1) {
bytecount = __HAL_DMA_GET_COUNTER(&hdma_usart2_rx);
rxlen485 = 256 - bytecount;
bytecount232 = __HAL_DMA_GET_COUNTER(&hdma_usart1_rx);
rxlen232 = 256 - bytecount232;
if(rxlen485 >= sizeof(struct header)) {
//start timer
struct header *pHeader = rxbuffer;
if(pHeader->size == rxlen485 - sizeof(struct header)) {
//do something
HAL_UART_DMAStop(&huart2);
if(HAL_UART_Receive_DMA(&huart2, rxbuffer, 256) != HAL_OK) {
while(1);
}
if(timeout) { // purely demonstrative ... the timeout part
//do something
HAL_UART_DMAStop(&huart2);
if(HAL_UART_Receive_DMA(&huart2, rxbuffer, 256) != HAL_OK) {
while(1);
}
}
}
if(rxlen232 >= sizeof(struct header)) {
struct header *pHeader = rxbuffer;
if(pHeader->size == rxlen232 - sizeof(struct header)) {
//do something
HAL_UART_DMAStop(&huart1);
if(HAL_UART_Receive_DMA(&huart1, rx232buffer, 256) != HAL_OK) {
while(1);
}
if(timeout) { // purely demonstrative ... the timeout part
//do something
HAL_UART_DMAStop(&huart1);
if(HAL_UART_Receive_DMA(&huart1, rx232buffer, 256) != HAL_OK) {
while(1);
}
}
}
}
}
}
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart) {
__NOP();
}
void HAL_UART_TxCpltCallback(UART_HandleTypeDef *huart) {
__NOP();
}
void USART2_IRQHandler(void)
{
/* USER CODE BEGIN USART2_IRQn 0 */
/* USER CODE END USART2_IRQn 0 */
HAL_UART_IRQHandler(&huart2);
/* USER CODE BEGIN USART2_IRQn 1 */
/* USER CODE END USART2_IRQn 1 */
}
void USART1_IRQHandler(void)
{
/* USER CODE BEGIN USART2_IRQn 0 */
/* USER CODE END USART2_IRQn 0 */
HAL_UART_IRQHandler(&huart1);
/* USER CODE BEGIN USART2_IRQn 1 */
/* USER CODE END USART2_IRQn 1 */
}
//----- in another file--------
void HAL_UART_MspInit(UART_HandleTypeDef* huart)
{
GPIO_InitTypeDef GPIO_InitStruct;
if(huart->Instance==USART1)
{
/* USER CODE BEGIN USART1_MspInit 0 */
/* USER CODE END USART1_MspInit 0 */
/* Peripheral clock enable */
__HAL_RCC_USART1_CLK_ENABLE();
/**USART1 GPIO Configuration
PA9 ------> USART1_TX
PA10 ------> USART1_RX
PA11 ------> USART1_CTS
PA12 ------> USART1_RTS
*/
GPIO_InitStruct.Pin = GPIO_PIN_9|GPIO_PIN_10;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_PULLUP;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
GPIO_InitStruct.Alternate = GPIO_AF7_USART1;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
GPIO_InitStruct.Pin = GPIO_PIN_11|GPIO_PIN_12;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
GPIO_InitStruct.Alternate = GPIO_AF7_USART1;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
/* USART1 DMA Init */
/* USART1_RX Init */
hdma_usart1_rx.Instance = DMA2_Stream2;
hdma_usart1_rx.Init.Channel = DMA_CHANNEL_4;
hdma_usart1_rx.Init.Direction = DMA_PERIPH_TO_MEMORY;
hdma_usart1_rx.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_usart1_rx.Init.MemInc = DMA_MINC_ENABLE;
hdma_usart1_rx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
hdma_usart1_rx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_usart1_rx.Init.Mode = DMA_CIRCULAR;
hdma_usart1_rx.Init.Priority = DMA_PRIORITY_LOW;
hdma_usart1_rx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
if (HAL_DMA_Init(&hdma_usart1_rx) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
__HAL_LINKDMA(huart,hdmarx,hdma_usart1_rx);
/* USART1_TX Init */
hdma_usart1_tx.Instance = DMA2_Stream7;
hdma_usart1_tx.Init.Channel = DMA_CHANNEL_4;
hdma_usart1_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
hdma_usart1_tx.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_usart1_tx.Init.MemInc = DMA_MINC_ENABLE;
hdma_usart1_tx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
hdma_usart1_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_usart1_tx.Init.Mode = DMA_NORMAL;
hdma_usart1_tx.Init.Priority = DMA_PRIORITY_LOW;
hdma_usart1_tx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
if (HAL_DMA_Init(&hdma_usart1_tx) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
__HAL_LINKDMA(huart,hdmatx,hdma_usart1_tx);
/* USER CODE BEGIN USART1_MspInit 1 */
/* USER CODE END USART1_MspInit 1 */
}
else if(huart->Instance==USART2)
{
/* USER CODE BEGIN USART2_MspInit 0 */
/* USER CODE END USART2_MspInit 0 */
/* Peripheral clock enable */
__HAL_RCC_USART2_CLK_ENABLE();
/**USART2 GPIO Configuration
PD5 ------> USART2_TX
PD6 ------> USART2_RX
*/
GPIO_InitStruct.Pin = GPIO_PIN_5|GPIO_PIN_6;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_PULLUP;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
GPIO_InitStruct.Alternate = GPIO_AF7_USART2;
HAL_GPIO_Init(GPIOD, &GPIO_InitStruct);
/* USART2 DMA Init */
/* USART2_RX Init */
hdma_usart2_rx.Instance = DMA1_Stream5;
hdma_usart2_rx.Init.Channel = DMA_CHANNEL_4;
hdma_usart2_rx.Init.Direction = DMA_PERIPH_TO_MEMORY;
hdma_usart2_rx.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_usart2_rx.Init.MemInc = DMA_MINC_ENABLE;
hdma_usart2_rx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
hdma_usart2_rx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_usart2_rx.Init.Mode = DMA_CIRCULAR;
hdma_usart2_rx.Init.Priority = DMA_PRIORITY_LOW;
hdma_usart2_rx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
if (HAL_DMA_Init(&hdma_usart2_rx) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
__HAL_LINKDMA(huart,hdmarx,hdma_usart2_rx);
/* USART2_TX Init */
hdma_usart2_tx.Instance = DMA1_Stream6;
hdma_usart2_tx.Init.Channel = DMA_CHANNEL_4;
hdma_usart2_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
hdma_usart2_tx.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_usart2_tx.Init.MemInc = DMA_MINC_ENABLE;
hdma_usart2_tx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
hdma_usart2_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_usart2_tx.Init.Mode = DMA_NORMAL;
hdma_usart2_tx.Init.Priority = DMA_PRIORITY_LOW;
hdma_usart2_tx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
if (HAL_DMA_Init(&hdma_usart2_tx) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
__HAL_LINKDMA(huart,hdmatx,hdma_usart2_tx);
HAL_NVIC_SetPriority(USART2_IRQn, 5, 0);
HAL_NVIC_EnableIRQ(USART2_IRQn);
}
}