在keil中怎么用ASSCI码码显示时间

在Keil中使用ASCII码显示时间需要使用STM32的定时器和串口功能。具体步骤如下：

1. 初始化串口：在Keil中打开STM32CubeMX向导，选择对应的MCU型号，在“Connectivity”中打开USART，并将波特率设置为9600。生成代码并添加到Keil工程中。

2. 初始化定时器：在Keil工程中添加定时器初始化函数，设置定时器的预分频器和计数器值，以达到想要的中断时间。

3. 编写中断服务程序：在定时器中断服务程序中，获取当前时间并转换成ASCII码，将其通过串口发送给PC端。

代码示例：

#include "stm32f1xx_hal.h"
#include <stdio.h>

UART_HandleTypeDef huart1;

TIM_HandleTypeDef htim2;

void SystemClock_Config(void);

static void MX_GPIO_Init(void);
static void MX_TIM2_Init(void);
static void MX_USART1_UART_Init(void);

void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
{
    if (htim->Instance == TIM2)
    {
        // 获取当前时间
        uint32_t time = HAL_GetTick();
        uint8_t buffer[64];

        // 将时间转换为ASCII码
        sprintf(buffer, "Time: %02d:%02d:%02d\r\n", (int)(time/(60*60*1000)), (int)(time/(60*1000)%60), (int)(time/(1000)%60));

        // 发送ASCII码
        HAL_UART_Transmit(&huart1, buffer, strlen((const char*)buffer), HAL_MAX_DELAY);
    }
}

int main(void)
{
    HAL_Init();
    SystemClock_Config();
    MX_GPIO_Init();
    MX_TIM2_Init();
    MX_USART1_UART_Init();
    HAL_TIM_Base_Start_IT(&htim2); // 启动定时器

    while (1)
    {
    }
}

static void MX_TIM2_Init(void)
{
    TIM_ClockConfigTypeDef sClockSourceConfig = {0};
    TIM_MasterConfigTypeDef sMasterConfig = {0};

    htim2.Instance = TIM2;
    htim2.Init.Prescaler = 7200 - 1; // 时钟频率72MHz，预分频器7200，计数器值为10000，即定时器中断时间为1秒
    htim2.Init.CounterMode = TIM_COUNTERMODE_UP;
    htim2.Init.Period = 10000 - 1;
    htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
    if (HAL_TIM_Base_Init(&htim2) != HAL_OK)
    {
        Error_Handler();
    }

    sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
    if (HAL_TIM_ConfigClockSource(&htim2, &sClockSourceConfig) != HAL_OK)
    {
        Error_Handler();
    }

    sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
    sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
    if (HAL_TIMEx_MasterConfigSynchronization(&htim2, &sMasterConfig) != HAL_OK)
    {
        Error_Handler();
    }
}

static void MX_USART1_UART_Init(void)
{
    huart1.Instance = USART1;
    huart1.Init.BaudRate = 9600;
    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();
    }
}

void Error_Handler(void)
{
    __disable_irq();
    while (1)
    {
    }
}

void SystemClock_Config(void)
{
    RCC_OscInitTypeDef RCC_OscInitStruct = {0};
    RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

    __HAL_RCC_PWR_CLK_ENABLE();
    __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
    RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
    RCC_OscInitStruct.HSIState = RCC_HSI_ON;
    RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
    RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
    RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI_DIV2;
    RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL16;
    if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
    {
        Error_Handler();
    }
    RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                                |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
    RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
    RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
    RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
    RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

    if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
    {
        Error_Handler();
    }
}

请注意：此示例仅供参考，具体实现方式可能因不同的MCU型号和代码环境而异。