STM32H750使用keil生成工程用来测量正弦波的频率和峰峰值，并输出到串口屏中

以下是基于Keil的STM32H750工程代码示例，实现测量正弦波的频率和峰峰值，并输出到串口屏中：

首先需要配置MCU的时钟，这里使用HSI时钟，时钟频率为64MHz：

RCC_OscInitTypeDef RCC_OscInitStruct = {0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
RCC_PeriphCLKInitTypeDef PeriphClkInitStruct = {0};

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;
RCC_OscInitStruct.PLL.PLLM = 1;
RCC_OscInitStruct.PLL.PLLN = 64;
RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV7;
RCC_OscInitStruct.PLL.PLLQ = RCC_PLLQ_DIV2;
RCC_OscInitStruct.PLL.PLLR = RCC_PLLR_DIV2;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
    Error_Handler();
}

PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_USART1;
PeriphClkInitStruct.Usart1ClockSelection = RCC_USART1CLKSOURCE_PCLK2;
if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct) != 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_DIV1;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_4) != HAL_OK)
{
    Error_Handler();
}

然后需要配置串口，这里使用USART1，波特率为115200：

UART_HandleTypeDef huart1;

huart1.Instance = USART1;
huart1.Init.BaudRate = 115200;
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();
}

接下来是测量正弦波的部分，这里使用TIM2和ADC1：

#define ADC_BUFFER_SIZE 2048
#define PWM_FREQUENCY   1000

uint32_t adc_buffer[ADC_BUFFER_SIZE];
volatile uint32_t adc_buffer_index = 0;
volatile uint32_t adc_buffer_half_full = 0;
float frequency = 0;
float peak_to_peak = 0;

void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
{
    if (htim->Instance == TIM2)
    {
        HAL_ADC_Start_IT(&hadc1);
    }
}

void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef *hadc)
{
    if (hadc->Instance == ADC1)
    {
        adc_buffer[adc_buffer_index++] = HAL_ADC_GetValue(hadc);

        if (adc_buffer_index == ADC_BUFFER_SIZE)
        {
            adc_buffer_index = 0;
            adc_buffer_half_full = 1;
        }
    }
}

void measure_frequency_and_peak_to_peak()
{
    uint32_t i = 0;
    float sum = 0;
    float max = 0;
    float min = 4096;

    HAL_TIM_Base_Start_IT(&htim2);
    HAL_ADC_Start_IT(&hadc1);

    while (adc_buffer_half_full == 0);

    HAL_TIM_Base_Stop_IT(&htim2);

    for (i = 0; i < ADC_BUFFER_SIZE; i++)
    {
        sum += adc_buffer[i];

        if (adc_buffer[i] > max)
        {
            max = adc_buffer[i];
        }

        if (adc_buffer[i] < min)
        {
            min = adc_buffer[i];
        }
    }

    frequency = ((float)HAL_RCC_GetHCLKFreq() / (PWM_FREQUENCY * ADC_BUFFER_SIZE)) * 2;
    peak_to_peak = ((float)(max - min) / 4096) * 3.3;
}

最后是输出到串口屏的部分，这里使用HAL库提供的UART发送函数，发送频率和峰峰值的值：

char message[64];

sprintf(message, "Frequency: %.2fHz\r\n", frequency);
HAL_UART_Transmit(&huart1, message, strlen(message), HAL_MAX_DELAY);

sprintf(message, "Peak-to-peak: %.2fV\r\n", peak_to_peak);
HAL_UART_Transmit(&huart1, message, strlen(message), HAL_MAX_DELAY);

完整的代码示例可以参考以下链接：https://github.com/Keenster/stm32h750-measure-sine-wave-frequency-and-peak-to-peak-value