[嵌入式]蓝桥杯STM32G431——测量PWM输出频率

PWM信号发生原理图

由上图可知两路PWM信号分别由PA15和PB4输入，其复用引脚图如下所示
参考STM32G431RB数据手册第61页

PB4引脚输入一路PWM的CubeMX配置(PA15配置同理仅将引脚改变）

打开中断，配置中断服务优先级

编写测量两路PWM输出频率值的代码

示波器测得pwm输出的频率范围

PWM1 output = 720hz-22.4khz
PWM2 output = 700hz-24.0khz

pwm_tim23.c文件

#include "pwm_tim23.h"

TIM_HandleTypeDef htim2;
TIM_HandleTypeDef htim3;	//句柄结构体

void PWM_TIM2_Init(void)	//定时器2初始化
{
  TIM_ClockConfigTypeDef sClockSourceConfig = {0};
  TIM_SlaveConfigTypeDef sSlaveConfig = {0};
  TIM_MasterConfigTypeDef sMasterConfig = {0};
  TIM_IC_InitTypeDef sConfigIC = {0};

  htim2.Instance = TIM2;
  htim2.Init.Prescaler = 79;
  htim2.Init.CounterMode = TIM_COUNTERMODE_UP;
  htim2.Init.Period = 65535;
  htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
  htim2.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
  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();
  }
  if (HAL_TIM_IC_Init(&htim2) != HAL_OK)
  {
    Error_Handler();
  }
  sSlaveConfig.SlaveMode = TIM_SLAVEMODE_RESET;
  sSlaveConfig.InputTrigger = TIM_TS_TI1FP1;
  sSlaveConfig.TriggerPolarity = TIM_INPUTCHANNELPOLARITY_RISING;
  sSlaveConfig.TriggerFilter = 0;
  if (HAL_TIM_SlaveConfigSynchro(&htim2, &sSlaveConfig) != HAL_OK)
  {
    Error_Handler();
  }
  sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
  sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
  if (HAL_TIMEx_MasterConfigSynchronization(&htim2, &sMasterConfig) != HAL_OK)
  {
    Error_Handler();
  }
  sConfigIC.ICPolarity = TIM_INPUTCHANNELPOLARITY_RISING;
  sConfigIC.ICSelection = TIM_ICSELECTION_DIRECTTI;
  sConfigIC.ICPrescaler = TIM_ICPSC_DIV1;
  sConfigIC.ICFilter = 0;
  if (HAL_TIM_IC_ConfigChannel(&htim2, &sConfigIC, TIM_CHANNEL_1) != HAL_OK)
  {
    Error_Handler();
  }
}

/* TIM3 init function */
void PWM_TIM3_Init(void) //定时器3初始化
{

  TIM_ClockConfigTypeDef sClockSourceConfig = {0};
  TIM_SlaveConfigTypeDef sSlaveConfig = {0};
  TIM_MasterConfigTypeDef sMasterConfig = {0};
  TIM_IC_InitTypeDef sConfigIC = {0};

  htim3.Instance = TIM3;
  htim3.Init.Prescaler = 79;
  htim3.Init.CounterMode = TIM_COUNTERMODE_UP;	
  htim3.Init.Period = 65535;
  htim3.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
  htim3.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
  if (HAL_TIM_Base_Init(&htim3) != HAL_OK)
  {
    Error_Handler();
  }
  sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
  if (HAL_TIM_ConfigClockSource(&htim3, &sClockSourceConfig) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_TIM_IC_Init(&htim3) != HAL_OK)
  {
    Error_Handler();
  }
  sSlaveConfig.SlaveMode = TIM_SLAVEMODE_RESET;
  sSlaveConfig.InputTrigger = TIM_TS_TI1FP1;
  sSlaveConfig.TriggerPolarity = TIM_INPUTCHANNELPOLARITY_RISING;
  sSlaveConfig.TriggerFilter = 0;
  if (HAL_TIM_SlaveConfigSynchro(&htim3, &sSlaveConfig) != HAL_OK)
  {
    Error_Handler();
  }
  sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
  sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
  if (HAL_TIMEx_MasterConfigSynchronization(&htim3, &sMasterConfig) != HAL_OK)
  {
    Error_Handler();
  }
  sConfigIC.ICPolarity = TIM_INPUTCHANNELPOLARITY_RISING;
  sConfigIC.ICSelection = TIM_ICSELECTION_DIRECTTI;
  sConfigIC.ICPrescaler = TIM_ICPSC_DIV1;
  sConfigIC.ICFilter = 0;
  if (HAL_TIM_IC_ConfigChannel(&htim3, &sConfigIC, TIM_CHANNEL_1) != HAL_OK)
  {
    Error_Handler();
  }

}

void HAL_TIM_Base_MspInit(TIM_HandleTypeDef* tim_baseHandle)	//IO口配置函数(包含time6）
{

	GPIO_InitTypeDef GPIO_InitStruct = {0};
  if(tim_baseHandle->Instance==TIM2)
  {
    /* TIM2 clock enable */
    __HAL_RCC_TIM2_CLK_ENABLE();

    __HAL_RCC_GPIOA_CLK_ENABLE();
    /**TIM2 GPIO Configuration
    PA15     ------> TIM2_CH1
    */
    GPIO_InitStruct.Pin = GPIO_PIN_15;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
    GPIO_InitStruct.Alternate = GPIO_AF1_TIM2;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

    /* TIM2 interrupt Init */
    HAL_NVIC_SetPriority(TIM2_IRQn, 3, 0);
    HAL_NVIC_EnableIRQ(TIM2_IRQn);
  }
  else if(tim_baseHandle->Instance==TIM3)
  {
    /* TIM3 clock enable */
    __HAL_RCC_TIM3_CLK_ENABLE();

    __HAL_RCC_GPIOB_CLK_ENABLE();
    /**TIM3 GPIO Configuration
    PB4     ------> TIM3_CH1
    */
    GPIO_InitStruct.Pin = GPIO_PIN_4;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
    GPIO_InitStruct.Alternate = GPIO_AF2_TIM3;
    HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

    /* TIM3 interrupt Init */
    HAL_NVIC_SetPriority(TIM3_IRQn, 3, 0);
    HAL_NVIC_EnableIRQ(TIM3_IRQn);
  }
  else if(tim_baseHandle->Instance==TIM6)
  {
    /* TIM6 clock enable */
    __HAL_RCC_TIM6_CLK_ENABLE();

    /* TIM6 interrupt Init */
    HAL_NVIC_SetPriority(TIM6_DAC_IRQn, 2, 0);
    HAL_NVIC_EnableIRQ(TIM6_DAC_IRQn);
  }
}

pwm_tim3.h文件

#ifndef __PWM_TIM3_H
#define __PWM_TIM3_H
#include "main.h"
extern TIM_HandleTypeDef htim3;
extern TIM_HandleTypeDef htim2;

void PWM_TIM3_Init(void);
void PWM_TIM2_Init(void);
#endif

main.c文件

#include "main.h"
#include "stdio.h"
#include "string.h"
#include "lcd.h"
#include "basic_tim6.h"
#include "pwm_tim3.h"

__IO uint32_t uwTick_LCD_State_Pointer;
unsigned char Lcd_Disp_String[21];
uint8_t i;	//用于基础定时器6中的变量
uint16_t pwm1_value;
uint16_t pwm2_value;	//用于pwm回调函数中的变量

void SystemClock_Config(void);
void LCD_Proc(void);
int main(void)
{

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

	//**LCD初始化
	LCD_Init();
	LCD_Clear(White);
	LCD_SetBackColor(White);
	LCD_SetTextColor(Blue);
	
	//基础定时器6的初始化 若没有或不需要基础定时器6可将此部分去除
	BASIC_TIM6_Init();
	HAL_TIM_Base_Start_IT(&htim6);

	//PWM初始化
	PWM_TIM2_Init(); 	//定时器2初始化
	PWM_TIM3_Init();	//定时器3初始化
	HAL_TIM_Base_Start_IT(&htim2);	//启动定时器2
	HAL_TIM_Base_Start_IT(&htim3);	//启动定时器3
	HAL_TIM_IC_Start_IT(&htim2 , TIM_CHANNEL_1);	//启动定时器2开启通道输入捕获并开启中断
	HAL_TIM_IC_Start_IT(&htim3 , TIM_CHANNEL_1);	//启动定时器3开启通道输入捕获并开启中断
	
  while (1)
  {
		LCD_Proc();
  }
}
void LCD_Proc(void)
{

	
	if(uwTick-uwTick_LCD_State_Pointer<300) return;
	uwTick_LCD_State_Pointer=uwTick;	
	
	memset(Lcd_Disp_String,0,sizeof(Lcd_Disp_String));
	sprintf((char*)Lcd_Disp_String, "Timer6_Num : %03d" ,i);
	LCD_DisplayStringLine(Line0, Lcd_Disp_String);
	
	memset(Lcd_Disp_String,0,sizeof(Lcd_Disp_String));
	sprintf((char*)Lcd_Disp_String, "  pwm1_freq: %06d  ",(unsigned int)1000000/pwm1_value); //频率值为1M/pwm_value 1M=1000000
	LCD_DisplayStringLine(Line3, Lcd_Disp_String);
	
	memset(Lcd_Disp_String,0,sizeof(Lcd_Disp_String));
	sprintf((char*)Lcd_Disp_String, "  pwm2_freq: %06d  ",(unsigned int)1000000/pwm2_value);
	LCD_DisplayStringLine(Line4, Lcd_Disp_String);
}

void HAL_TIM_IC_CaptureCallback(TIM_HandleTypeDef *htim) //输入捕获中断回调函数
{
	if(htim->Instance == TIM2)	//加判断语句用于判别是time2还是time3
  {
		if(htim->Channel == HAL_TIM_ACTIVE_CHANNEL_1)
		{
			pwm2_value = HAL_TIM_ReadCapturedValue(htim, TIM_CHANNEL_1)+1;
		}
	}
	
	if(htim->Instance == TIM3)
  {
		if(htim->Channel == HAL_TIM_ACTIVE_CHANNEL_1)
		{
			pwm1_value = HAL_TIM_ReadCapturedValue(htim, TIM_CHANNEL_1)+1;
		}
	}
	
}

void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)	//基本定时器6中断回调函数
{
	if(htim->Instance == TIM6)
	{
		i++;
		HAL_TIM_Base_Start_IT(&htim6);
	}
}

测量到的最低频率效果图为