STM32 PWM驱动LED灯、舵机和直流电机详解

文章目录

一、知识点补充

1.PWM波输出与GPIO的引脚对应关系图

a. TIM2的引脚复用子啊PA0引脚上，所以TIM2、CH1、PA0三者是捆绑在一起的，即在PA0引脚上通过TIM2通道1CH1输出PWM
b. TIM2、CH1、PA0三者一般是捆绑在一起，但可以通过重映射改变
c. TIM2、CH2、PA1同理

2.重映射简介

改为PA15，选择重映射方式1或完全重映射
在时钟开启后写入

	RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);
	GPIO_PinRemapConfig(GPIO_PartialRemap1_TIM2, ENABLE);
	GPIO_PinRemapConfig(GPIO_Remap_SWJ_JTAGDisable, ENABLE);  //PA15为调试端口，需要解除调试端

若想要让PA15、PB3、PB4这三个引脚当作普通GPIO来使用，则加第一、三句，打开AFIO时钟，让AFIO时钟将JTAG复用解除掉
如果想要重映射定时器或者其他外设的复用引脚，加第一句和第二句，就要先打开AFIO时钟，再用AFIO重映射外设复用的引脚，
若重映射的引脚正好是调试端口，则三句全加上

3.计数器的计算

PWM频率=计数器更新频率
比如要产生一个频率为1KHz,占空比为50%，分辨率为1%的PWM波形
72M/(PSC+1)/ (ARR+1)=1000
CCR/(ARR+1)=0.5
1/(ARR+1)=0.01
计算得：ARR=99，CCR=50, PSC=720-1;

4.基本步骤

第一步：RCC开启时钟，打开TIM外设和GPIO外设的时钟
第二步：配置时基单元，包括时基单元和时基单元前的时钟源选择（不选择则默认内部时钟）
第三步：配置输出比较单元，里面包括CCR的值、输出比较模式、极性选择、输出使能（结构体配置）
第四步：配置GPIO口，初始化为复用推挽输出的配置
第五步：运行控制，启动计数器，就能输出PWM波

5.输出比较模式简介

常用模式为 PWM1模式1

二、实例

1.PWM驱动LED灯

PWM.c

#include "stm32f10x.h"                  // Device header

void PWM_Init(void)	
{
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);   //第一步，开启时钟
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
	
//	RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);
//	GPIO_PinRemapConfig(GPIO_PartialRemap1_TIM2, ENABLE);
//	GPIO_PinRemapConfig(GPIO_Remap_SWJ_JTAGDisable, ENABLE);
	
	GPIO_InitTypeDef GPIO_InitStructure;  //第四步，配置GPIO
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;		//GPIO_Pin_15;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOA, &GPIO_InitStructure);
	
	TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;   //第二步，配置时基单元
	TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;
	TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;
	TIM_TimeBaseInitStructure.TIM_Period = 100 - 1;		//ARR
	TIM_TimeBaseInitStructure.TIM_Prescaler = 720 - 1;		//PSC
	TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;
	TIM_TimeBaseInit(TIM2, &TIM_TimeBaseInitStructure);

	
	TIM_OCInitTypeDef TIM_OCInitStructure;   //第三步，配置输出比较单元（CCR）
	TIM_OCStructInit(&TIM_OCInitStructure);  //初始化所以结构体（结构体中有带N的变量，是高级配置输出比较单元才有的，本次实例不需要用到，初始化后让他不影响别的模块）
	TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;  //设置比较输出模式
	TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;  //设置极性
	TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;  //设置输出使能
	TIM_OCInitStructure.TIM_Pulse = 0;		//CCR（0-0xff）
	TIM_OC1Init(TIM2, &TIM_OCInitStructure);  
	
	TIM_Cmd(TIM2,ENABLE);//第五步，运行控制启动
	
}


void PWM_SetCompare1(uint16_t Compare) //由main.c设置占空比
{
	TIM_SetCompare1(TIM2,Compare); 
}

PWM.h

#ifndef  __PWM_H__
#define  __PWM_H__

void PWM_SetCompare1(uint16_t Compare);
void PWM_Init(void);

#endif

main.c

#include "stm32f10x.h"                  // Device header
#include "Delay.h"
#include "OLED.h"
#include "PWM.h"

uint8_t i;

int main(void)
{
	OLED_Init();
	PWM_Init();
	while(1)
	{
		for(i=0;i<=100;i++)  更改CCR值
		{
			PWM_SetCompare1(i);
			Delay_ms(10);
		}
		for(i=0;i<=100;i++)
		{
			PWM_SetCompare1(100-i);
			Delay_ms(10);
		}	
	}
}

2.PWM驱动舵机

参数计算

舵机要求频率 ：50Hz(周期为20ms)
舵机角度控制（占空比）：0.5-2.5ms(时长)
(3个变量，2个方程)解不是唯一的
为方便计算
取PSC+1=72,ARR+1=20k
当CCR=500时，高电平时长为0.5ms 

PWM.c

#include "stm32f10x.h"                  // Device header

void PWM_Init(void)	
{
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);

	GPIO_InitTypeDef GPIO_InitStructure;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
			GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1;		//GPIO_Pin_15;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOA, &GPIO_InitStructure);
	
	TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
	TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;
	TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;
			TIM_TimeBaseInitStructure.TIM_Period = 20000 - 1;		//ARR
			TIM_TimeBaseInitStructure.TIM_Prescaler = 72 - 1;	//PSC
	TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;
	TIM_TimeBaseInit(TIM2, &TIM_TimeBaseInitStructure);

	
	TIM_OCInitTypeDef TIM_OCInitStructure;
	TIM_OCStructInit(&TIM_OCInitStructure);
	TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
	TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
	TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
	TIM_OCInitStructure.TIM_Pulse = 0;		//CCR
	TIM_OC2Init(TIM2, &TIM_OCInitStructure);
	
	TIM_Cmd(TIM2,ENABLE);
	
}


		void PWM_SetCompare2(uint16_t Compare)  //变为通道2
{
	TIM_SetCompare2(TIM2,Compare);
}

Servo.c

#include "stm32f10x.h"                  // Device header
#include "PWM.h"
 
void Servo_Init(void)
{
	PWM_Init();
}
 
void Servo_SetAngle(float Angle)  //参数为浮点型，方便写入
{
	PWM_SetCompare2(Angle / 180 * 2000 + 500);
}

main.c

#include "stm32f10x.h"                  // Device header
#include "Delay.h"
#include "OLED.h"
#include "Servo.h"
#include "Key.h"
 
uint8_t KeyNum;
float Angle;
 
int main(void)
{
	OLED_Init();
	Servo_Init();
	Init_KEY();
	
	OLED_ShowString(1, 1, "Angle:");
	
	while (1)
	{
		KeyNum = Key_Getnum();
		if (KeyNum == 1)
		{
			Angle += 30;
			if (Angle > 180)
			{
				Angle = 0;
			}
		}
		Servo_SetAngle(Angle);
		OLED_ShowNum(1, 7, Angle, 3);
	}
}

3.PWM驱动直流电机

pwm.c

#include "stm32f10x.h"                  // Device header

void PWM_Init(void)	
{
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
	
	
	GPIO_InitTypeDef GPIO_InitStructure;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
			GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;		//GPIO_Pin_15;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOA, &GPIO_InitStructure);
	
	TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
	TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;
	TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;
			TIM_TimeBaseInitStructure.TIM_Period = 100 - 1;		//ARR
			TIM_TimeBaseInitStructure.TIM_Prescaler = 36 - 1;		//PSC
	TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;
	TIM_TimeBaseInit(TIM2, &TIM_TimeBaseInitStructure);

	
	TIM_OCInitTypeDef TIM_OCInitStructure;
	TIM_OCStructInit(&TIM_OCInitStructure);
	TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
	TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
	TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
	TIM_OCInitStructure.TIM_Pulse = 0;		//CCR
			TIM_OC3Init(TIM2, &TIM_OCInitStructure);
	
	TIM_Cmd(TIM2,ENABLE);
	
}


		void PWM_SetCompare3(uint16_t Compare)
{
	TIM_SetCompare3(TIM2,Compare);
}

Motor.c

#include "stm32f10x.h"                  // Device header
#include "PWM.h"
 
void Motor_Init(void)
{
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
	
	GPIO_InitTypeDef GPIO_InitStructure;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4 | GPIO_Pin_5;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOA, &GPIO_InitStructure);
	
	PWM_Init();
}
 
void Motor_SetSpeed(int8_t Speed)
{
	if (Speed >= 0)//正转
	{
		GPIO_SetBits(GPIOA, GPIO_Pin_4);
		GPIO_ResetBits(GPIOA, GPIO_Pin_5);
		PWM_SetCompare3(Speed);
	}
	else
	{
		GPIO_ResetBits(GPIOA, GPIO_Pin_4);//反转
		GPIO_SetBits(GPIOA, GPIO_Pin_5);
		PWM_SetCompare3(-Speed);
	}
}

main.c

#include "stm32f10x.h"                  // Device header
#include "Delay.h"
#include "OLED.h"
#include "Motor.h"
#include "Key.h"
 
uint8_t KeyNum;
int8_t Speed;
 
int main(void)
{
	OLED_Init();
	Motor_Init();
	Init_KEY();
	
	OLED_ShowString(1, 1, "Speed:");
	
	while (1)
	{
		KeyNum = Key_Getnum();
		if (KeyNum == 1)
		{
			Speed += 20;
			if (Speed > 100)
			{
				Speed = -100;
			}
		}
		Motor_SetSpeed(Speed);
		OLED_ShowSignedNum(1, 7, Speed, 3);
	}
}