[STM32] 1. 串口

CubeMX配置

1. 串口全局中断
2. DMA 普通配置(Normal Mode/TX RX DMA Request/全字节)

单字接收与buff 接收

注意事项：

1. 单字接收每接收一个字节触发一次回调。
2. buff接收是等到空闲才触发回调。
3. 理论上中断也能做buff接收。
4. freeRTOS的优先级只能管理 5 - 16级(这里假设freeRTOS和HAL库优先级一样)，因此串口中断的优先级只能填 5 以后的。

#include <string.h>
#include "default_task.h"
#include "main.h"
#include "syscfg.h"
#include "FreeRTOS.h"
#include "task.h"
#include "usart.h"
#include "semphr.h"

uint8_t recv_buff[255];
uint8_t recv_data = 0;
extern DMA_HandleTypeDef hdma_usart2_rx;
extern DMA_HandleTypeDef hdma_usart2_tx;
extern SemaphoreHandle_t xBinarySemaphore;

void recv_task(void *pt){
    HAL_UARTEx_ReceiveToIdle_DMA(&huart2, recv_buff, sizeof(recv_buff));
    //HAL_UART_Receive_IT(&huart2, &recv_data, 1);
    for(;;){
        if(xSemaphoreTake(xBinarySemaphore, portMAX_DELAY)) {
            LOGI("%s\r\n",recv_buff);
            memset(recv_buff,0,sizeof(recv_buff));
        }
    }
}

BaseType_t xHigherPriorityTaskWoken = pdFALSE;
void HAL_UARTEx_RxEventCallback(UART_HandleTypeDef *huart, uint16_t Size) {
    if (huart->Instance == USART2) {
        uint8_t size = sizeof(recv_buff) - __HAL_DMA_GET_COUNTER(&hdma_usart2_rx);
        //HAL_UART_Transmit_DMA(&huart2, recv_buff, size);

        xSemaphoreGiveFromISR(xBinarySemaphore, &xHigherPriorityTaskWoken);
        if (xHigherPriorityTaskWoken == pdTRUE) {
            portYIELD_FROM_ISR(xHigherPriorityTaskWoken);
        }

        HAL_UARTEx_ReceiveToIdle_DMA(&huart2, recv_buff, sizeof(recv_buff));
    }
}

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart){
    if(huart == &huart2){
        HAL_UART_Transmit(&huart2, &recv_data, 1,999);
        HAL_UART_Receive_IT(&huart2, &recv_data, 1);
    }
}