基于STM32F407VET6芯片搭载FreeRTOS物联网操作系统消息队列，实现串口发送命令：openled \ closeled ，打开或者关闭板载的led实验结果

首先，需要在STM32F407VET6上搭载FreeRTOS操作系统，并且实现串口通信功能。接下来，我们可以通过消息队列来实现控制板载LED的开关。

在主函数中，我们创建一个消息队列，然后创建一个任务来接收串口命令并将命令发送到消息队列中。另外，我们还需要创建一个任务来读取消息队列中的数据，并根据命令来控制LED的开关。

下面是一个简单的示例代码：

#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"
#include "stm32f4xx.h"
#include "stm32f4xx_hal.h"

#define LED_PIN GPIO_PIN_13
#define LED_PORT GPIOC

TaskHandle_t xTask1Handle;
TaskHandle_t xTask2Handle;

QueueHandle_t xQueue;

void LED_Init(void)
{
    GPIO_InitTypeDef GPIO_InitStruct = {0};
    __HAL_RCC_GPIOC_CLK_ENABLE();

    GPIO_InitStruct.Pin = LED_PIN;
    GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
    GPIO_InitStruct.Pull = GPIO_PULLUP;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;

    HAL_GPIO_Init(LED_PORT, &GPIO_InitStruct);
}

void USART1_Init(void)
{
    GPIO_InitTypeDef GPIO_InitStruct = {0};
    USART_InitTypeDef USART_InitStruct = {0};
    NVIC_InitTypeDef NVIC_InitStruct = {0};

    __HAL_RCC_GPIOA_CLK_ENABLE();
    __HAL_RCC_USART1_CLK_ENABLE();

    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);

    USART_InitStruct.BaudRate = 115200;
    USART_InitStruct.WordLength = USART_WORDLENGTH_8B;
    USART_InitStruct.StopBits = USART_STOPBITS_1;
    USART_InitStruct.Parity = USART_PARITY_NONE;
    USART_InitStruct.Mode = USART_MODE_TX_RX;
    USART_InitStruct.CLKPolarity = USART_POLARITY_LOW;
    USART_InitStruct.CLKPhase = USART_PHASE_1EDGE;
    USART_InitStruct.CLKLastBit = USART_LASTBIT_DISABLE;

    HAL_USART_Init(&USART_InitStruct);

    NVIC_InitStruct.NVIC_IRQChannel = USART1_IRQn;
    NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority = 0;
    NVIC_InitStruct.NVIC_IRQChannelSubPriority = 0;
    NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE;

    HAL_NVIC_Init(&NVIC_InitStruct);

    HAL_NVIC_EnableIRQ(USART1_IRQn);
}

void USART1_IRQHandler(void)
{
    BaseType_t xHigherPriorityTaskWoken = pdFALSE;
    char cReceivedChar = 0;

    if (__HAL_USART_GET_FLAG(&huart1, USART_FLAG_RXNE) != RESET)
    {
        __HAL_USART_CLEAR_FLAG(&huart1, USART_FLAG_RXNE);

        cReceivedChar = (char)(huart1.Instance->DR & 0xFF);

        xQueueSendFromISR(xQueue, &cReceivedChar, &xHigherPriorityTaskWoken);
    }

    portYIELD_FROM_ISR(xHigherPriorityTaskWoken);
}

void vTask1(void *pvParameters)
{
    char cCommand = 0;

    while (1)
    {
        if (HAL_USART_Receive(&huart1, (uint8_t *)&cCommand, 1, 1000) == HAL_OK)
        {
            xQueueSend(xQueue, &cCommand, 0);
        }
    }
}

void vTask2(void *pvParameters)
{
    char cReceivedChar = 0;

    while (1)
    {
        if (xQueueReceive(xQueue, &cReceivedChar, portMAX_DELAY) == pdTRUE)
        {
            switch (cReceivedChar)
            {
            case 'o':
                HAL_GPIO_WritePin(LED_PORT, LED_PIN, GPIO_PIN_SET);
                break;

            case 'c':
                HAL_GPIO_WritePin(LED_PORT, LED_PIN, GPIO_PIN_RESET);
                break;

            default:
                break;
            }
        }
    }
}

int main(void)
{
    HAL_Init();
    LED_Init();
    USART1_Init();

    xQueue = xQueueCreate(10, sizeof(char));
    xTaskCreate(vTask1, "Task 1", configMINIMAL_STACK_SIZE, NULL, tskIDLE_PRIORITY + 1, &xTask1Handle);
    xTaskCreate(vTask2, "Task 2", configMINIMAL_STACK_SIZE, NULL, tskIDLE_PRIORITY + 1, &xTask2Handle);

    vTaskStartScheduler();

    while (1)
    {
    }
}

在该示例中，我们使用消息队列来实现串口命令的传递和控制LED的开关。当接收到字符'o'时，我们将板载LED打开，当接收到字符'c'时，我们将板载LED关闭。通过这种方式，我们可以通过串口来控制板载LED的开关。