目录
一、轮询模式
1.1 配置USART2为异步模式
1.2 500ms发送一次消息
1.3 通信结果
1.4 串口控制LED
二、中断收发
2.1 开启中断
2.2 中断发送接收
2.2.1 中断发送只需要调用接口
2.2.2 中断接收
2.3 实验结果
三、DMA模式与收发不定长数据
3.1 DMA通道配置
3.2 DMA发送接收函数
3.3 使用空闲中断接收不定长数据
uint8_t reciveDate[2];
while (1)
{
HAL_UART_Receive(&huart1, reciveDate, 2, HAL_MAX_DELAY);
HAL_UART_Transmit(&huart1, reciveDate, 2, 100);
GPIO_PinState state=GPIO_PIN_SET;
if(reciveDate[1]=='1')
{
state=GPIO_PIN_RESET;
}
if(reciveDate[0]=='R')
{
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_8, state);
}
else if(reciveDate[0]=='G')
{
HAL_GPIO_WritePin(GPIOD, GPIO_PIN_2, state);
}
}
}
HAL_UART_Transmit_IT(&huart1, reciveDate, 2);
①在程序起始开启中断
②重新定义stm32f1xx_hal_uart.c中的函数
__weak void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
/* Prevent unused argument(s) compilation warning */
UNUSED(huart);
/* NOTE: This function should not be modified, when the callback is needed,
the HAL_UART_RxCpltCallback could be implemented in the user file
*/
}
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
HAL_UART_Transmit_IT(&huart1, reciveDate, 2);
GPIO_PinState state = GPIO_PIN_SET;
if (reciveDate[1] == '1')
{
state = GPIO_PIN_RESET;
}
if (reciveDate[0] == 'G')
{
HAL_GPIO_WritePin(GPIOD, GPIO_PIN_2, state);
}
HAL_UART_Receive_IT(&huart1, reciveDate, 2);//再次启动中断接收
}
只需要将_IT修改为_DMA即可,DMA模式还是有中断参与其中
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
HAL_UART_Transmit_DMA(&huart1, reciveDate, 2);//dma发送
GPIO_PinState state = GPIO_PIN_SET;
if (reciveDate[1] == '1')
{
state = GPIO_PIN_RESET;
}
if (reciveDate[0] == 'G')
{
HAL_GPIO_WritePin(GPIOD, GPIO_PIN_2, state);
}
HAL_UART_Receive_DMA(&huart1, reciveDate, 2);//DMA接收
}
只有当接收端不再有数据输入时才会触发空闲中断,重新定义
__weak void HAL_UARTEx_RxEventCallback(UART_HandleTypeDef *huart, uint16_t Size)
{
/* Prevent unused argument(s) compilation warning */
UNUSED(huart);
UNUSED(Size);
/* NOTE : This function should not be modified, when the callback is needed,
the HAL_UARTEx_RxEventCallback can be implemented in the user file.
*/
}
void HAL_UARTEx_RxEventCallback(UART_HandleTypeDef *huart, uint16_t Size)
{
if(huart==&huart1)
{
HAL_UART_Transmit_DMA(&huart1, reciveDate, Size);//发�?�与接收相同的Size长度的字节数
HAL_UARTEx_ReceiveToIdle_DMA(&huart1, reciveDate, sizeof(reciveDate));//接收不定长数�?
}
}