若用HAL库该怎么写

如果你使用了HAL库，那么程序会更加简化。以下是使用HAL库的示例程序。

首先，在初始化程序中初始化IO口和LED灯，代码如下：

/* GPIO Ports Clock Enable */
__HAL_RCC_GPIOA_CLK_ENABLE();
__HAL_RCC_GPIOD_CLK_ENABLE();

/*Configure GPIO pin : PA0 */
GPIO_InitStruct.Pin = GPIO_PIN_0;
GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

/*Configure GPIO pin : PD12 */
GPIO_InitStruct.Pin = GPIO_PIN_12;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(GPIOD, &GPIO_InitStruct);

/*Initial status for LED*/
HAL_GPIO_WritePin(GPIOD, GPIO_PIN_12, GPIO_PIN_RESET);

接下来，在主函数中，你可以读取IO口电平并控制LED灯亮灭，代码如下：

while (1)
{
    /* Read input IO value */
    uint32_t io_value = HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_0);

    /* Control LED based on IO value */
    if (io_value == GPIO_PIN_SET)
    {
        /* IO is high, turn on LED */
        HAL_GPIO_WritePin(GPIOD, GPIO_PIN_12, GPIO_PIN_SET);
    }
    else
    {
        /* IO is low, turn off LED */
        HAL_GPIO_WritePin(GPIOD, GPIO_PIN_12, GPIO_PIN_RESET);
    }
}

这里假设你要读取的IO口为GPIOA的第0个引脚，控制的LED灯接在GPIOD的第12个引脚上。

需要注意的是，使用HAL库时，你需要在main函数之前调用`HAL_Init()`函数来初始化HAL库。同时，你还需要在main函数中调用`HAL_GPIO_Init()`函数来初始化GPIO口。完整代码如下：

#include "main.h"

/* Private variables ---------------------------------------------------------*/
GPIO_InitTypeDef GPIO_InitStruct;

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);

/* Main function -------------------------------------------------------------*/
int main(void)
{
    /* MCU Configuration--------------------------------------------------------*/
    /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
    HAL_Init();

    /* Configure the system clock */
    SystemClock_Config();

    /* Initialize all configured peripherals */
    /* GPIO Ports Clock Enable */
    __HAL_RCC_GPIOA_CLK_ENABLE();
    __HAL_RCC_GPIOD_CLK_ENABLE();

    /*Configure GPIO pin : PA0 */
    GPIO_InitStruct.Pin = GPIO_PIN_0;
    GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

    /*Configure GPIO pin : PD12 */
    GPIO_InitStruct.Pin = GPIO_PIN_12;
    GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
    HAL_GPIO_Init(GPIOD, &GPIO_InitStruct);

    /*Initial status for LED*/
    HAL_GPIO_WritePin(GPIOD, GPIO_PIN_12, GPIO_PIN_RESET);

    /* Infinite loop */
    while (1)
    {
        /* Read input IO value */
        uint32_t io_value = HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_0);

        /* Control LED based on IO value */
        if (io_value == GPIO_PIN_SET)
        {
            /* IO is high, turn on LED */
            HAL_GPIO_WritePin(GPIOD, GPIO_PIN_12, GPIO_PIN_SET);
        }
        else
        {
            /* IO is low, turn off LED */
            HAL_GPIO_WritePin(GPIOD, GPIO_PIN_12, GPIO_PIN_RESET);
        }
    }
}

/* System Clock Configuration */
void SystemClock_Config(void)
{
    RCC_OscInitTypeDef RCC_OscInitStruct = {0};
    RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

    /** Initializes the RCC Oscillators according to the specified parameters
  * in the RCC_OscInitTypeDef structure.
  */
    RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
    RCC_OscInitStruct.HSIState = RCC_HSI_ON;
    RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
    RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
    if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
    {
        Error_Handler();
    }
    /** Initializes the CPU, AHB and APB buses clocks
  */
    RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_SYSCLK
                                  | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2;
    RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
    RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
    RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
    RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

    if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
    {
        Error_Handler();
    }
}

这样，你就完成了使用HAL库读取IO口电平并控制LED灯亮灭的程序。