【STM32G431RBTx】备战蓝桥杯嵌入式→基本模块→TIM→OC输出
文章目录
-
- 前言
-
- 1.CubeMx的配置步骤
- 2.生成工程
- 3.测试代码
- 4.演示效果
- 总结
前言
定时器具有
1.Base
2.PWM
3.IC
4.OC
这四种功能，前面我们以及讲完了Base(按键部分)，PWM功能，IC功能，接下来我们要学习的是定时器的OC(输出比较)功能。
1.CubeMx的配置步骤
修改上一次IC捕获的ioc文件来生成工程
修改PA2，PA3为定时器15的通道1和通道2。
2.生成工程
点击GENERATE CODE生成代码后点击Open Project即可。
3.测试代码
interrupt.h:
#ifndef __INTERRUPT_H__
#define __INTERRUPT_H__
#include "main.h"
void HAL_TIM_IC_CaptureCallback(TIM_HandleTypeDef *htim);
void HAL_TIM_OC_DelayElapsedCallback(TIM_HandleTypeDef *htim);
#endif
interrupt.c:
#include "interrupt.h"
#include "lcd.h"
#include "stdio.h"
unsigned int Period = 0;
unsigned int HighTime = 0;
unsigned char OC1_Duty = 25;
unsigned char OC2_Duty = 75;
unsigned short OC1_Pulse = 1000;
unsigned short OC2_Pulse = 4000;
void HAL_TIM_IC_CaptureCallback(TIM_HandleTypeDef *htim)
{
if(htim->Instance == TIM2)
{
if(htim->Channel == HAL_TIM_ACTIVE_CHANNEL_1)
{
Period = HAL_TIM_ReadCapturedValue(htim, TIM_CHANNEL_1); //读取直接通道
HighTime = HAL_TIM_ReadCapturedValue(htim, TIM_CHANNEL_2); //读取间接通道
__HAL_TIM_SetCounter(htim, 0);
HAL_TIM_IC_Start_IT(htim, TIM_CHANNEL_1); //开启中断以便于下次采值
HAL_TIM_IC_Start_IT(htim, TIM_CHANNEL_2);
}
}
}
void HAL_TIM_OC_DelayElapsedCallback(TIM_HandleTypeDef *htim)
{
if(htim->Instance == TIM15)
{
unsigned short CapVal = 0;
if(htim->Channel == HAL_TIM_ACTIVE_CHANNEL_1)
{
CapVal = __HAL_TIM_GetCompare(htim, TIM_CHANNEL_1);
if(HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_2) == GPIO_PIN_RESET)
{
__HAL_TIM_SET_COMPARE(htim, TIM_CHANNEL_1, CapVal + OC1_Pulse - OC1_Duty / 100.0 * OC1_Pulse);
}
else
{
__HAL_TIM_SET_COMPARE(htim, TIM_CHANNEL_1, CapVal + OC1_Duty / 100.0 * OC1_Pulse);
}
}
else if(htim->Channel == HAL_TIM_ACTIVE_CHANNEL_2)
{
CapVal = __HAL_TIM_GetCompare(htim, TIM_CHANNEL_2);
if(HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_3) == GPIO_PIN_RESET)
{
__HAL_TIM_SetCompare(htim, TIM_CHANNEL_2, CapVal + (1 - OC2_Duty / 100.0) * OC2_Pulse);
}
else
{
__HAL_TIM_SetCompare(htim, TIM_CHANNEL_2, CapVal + OC2_Duty / 100.0 * OC2_Pulse);
}
}
}
}
main.c:
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* © Copyright (c) 2023 STMicroelectronics.
* All rights reserved.
*
* This software component is licensed by ST under BSD 3-Clause license,
* the "License"; You may not use this file except in compliance with the
* License. You may obtain a copy of the License at:
* opensource.org/licenses/BSD-3-Clause
*
******************************************************************************
*/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "tim.h"
#include "gpio.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "lcd.h"
#include "stdio.h"
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
/* USER CODE BEGIN PV */
extern unsigned int Period;
extern unsigned int HighTime;
char text[30];
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
/* USER CODE BEGIN PFP */
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
/**
* @brief The application entry point.
* @retval int
*/
int main(void)
{
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* USER CODE BEGIN Init */
/* USER CODE END Init */
/* Configure the system clock */
SystemClock_Config();
/* USER CODE BEGIN SysInit */
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_TIM2_Init();
MX_TIM15_Init();
MX_TIM3_Init();
/* USER CODE BEGIN 2 */
HAL_TIM_IC_Start_IT(&htim2, TIM_CHANNEL_1);
HAL_TIM_IC_Start_IT(&htim2, TIM_CHANNEL_2);
HAL_TIM_OC_Start_IT(&htim15, TIM_CHANNEL_1);
HAL_TIM_OC_Start_IT(&htim15, TIM_CHANNEL_2);
LCD_Init();
LCD_Clear(Black);
LCD_SetBackColor(Black);
LCD_SetTextColor(White);
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
sprintf(text, "frq:%.2f ", 1000000.0 / Period); //分频成1MHz所以这里1000000.0作为被除数
LCD_DisplayStringLine(Line0, text);
sprintf(text, "Duty:%.2f ", HighTime / (float)Period * 100); //占空比为高电平时间 / 周期 * 100%
LCD_DisplayStringLine(Line1, text);
}
/* USER CODE END 3 */
}
/**
* @brief System Clock Configuration
* @retval None
*/
void SystemClock_Config(void)
{
RCC_OscInitTypeDef RCC_OscInitStruct = {0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
/** Configure the main internal regulator output voltage
*/
HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1);
/** Initializes the RCC Oscillators according to the specified parameters
* in the RCC_OscInitTypeDef structure.
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
RCC_OscInitStruct.HSEState = RCC_HSE_ON;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
RCC_OscInitStruct.PLL.PLLM = RCC_PLLM_DIV3;
RCC_OscInitStruct.PLL.PLLN = 20;
RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
RCC_OscInitStruct.PLL.PLLQ = RCC_PLLQ_DIV2;
RCC_OscInitStruct.PLL.PLLR = RCC_PLLR_DIV2;
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_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_2) != HAL_OK)
{
Error_Handler();
}
}
/* USER CODE BEGIN 4 */
/* USER CODE END 4 */
/**
* @brief This function is executed in case of error occurrence.
* @retval None
*/
void Error_Handler(void)
{
/* USER CODE BEGIN Error_Handler_Debug */
/* User can add his own implementation to report the HAL error return state */
__disable_irq();
while (1)
{
}
/* USER CODE END Error_Handler_Debug */
}
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @param file: pointer to the source file name
* @param line: assert_param error line source number
* @retval None
*/
void assert_failed(uint8_t *file, uint32_t line)
{
/* USER CODE BEGIN 6 */
/* User can add his own implementation to report the file name and line number,
ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
/* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */
/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
4.演示效果
总结
从结果来看我们目标是PA2输出1000Hz占空比为25%的PWM波但最后测量频率为1026和23%的波形，误差比较大。PA3目标输出250Hz占空比为75%的PWM波，但最后输出的是252.84Hz和74.72%的PWM波，误差虽然存在但与PA2输出的波形比较，误差算是少一点，我们可以知道OC输出高频率PWM波时存在很严重的波形失真现象，但在输出低频率PWM波时这种情况就好一点，TIM的PWM模式不会有这样的问题但是PWM模式下定时器各个通道输出PWM波频率相同(占空比可以不同)，不能实现每个通道占空比不同且频率也不同的情况。OC模式下虽然不支持输出高频率PWM波，但是它能实现每个通道的PWM波频率不同占空比也不同。
以上就是OC的配置过程，测试代码以及测试效果
参考的学习视频:【STM32】输出比较模式讲解以及STM32CUBEMX+MDK代码实现
之前的模块配置方法及测试:
【STM32G431RBTx】备战蓝桥杯嵌入式→基本模块→LED
【STM32G431RBTx】备战蓝桥杯嵌入式→基本模块→LCD
【STM32G431RBTx】备战蓝桥杯嵌入式→基本模块→KEY→单击
【STM32G431RBTx】备战蓝桥杯嵌入式→基本模块→KEY→长按(持续响应)以及双击
【STM32G431RBTx】备战蓝桥杯嵌入式→基本模块→TIM→PWM
【STM32G431RBTx】备战蓝桥杯嵌入式→基本模块→ADC
【STM32G431RBTx】备战蓝桥杯嵌入式→基本模块→I2C→M24C02
【STM32G431RBTx】备战蓝桥杯嵌入式→基本模块→UART
【STM32G431RBTx】备战蓝桥杯嵌入式→基本模块→TIM→IC捕获