目录
一、输出比较简介
二、PWM简介
三、输出比较通道（通用）
四、输出比较通道（高级）
五、输出比较模式
六、PWM基本结构
七、PWM参数计算
八、外设介绍
8.1 舵机
8.2 直流电机及驱动
九、开发步骤
十、输出比较库函数
十一、实验
9.1 PWM驱动LED呼吸灯
9.2 PWM驱动舵机
9.3 PWM驱动直流电机
一、输出比较简介
>OC（Output Compare）输出比较
>输出比较可以通过比较CNT与CCR（捕获/比较寄存器）值的关系，来对输出电平进行置1、置0或翻转的操作，用于输出一定频率和占空比的PWM波形
>每个高级定时器和通用定时器都拥有4个输出比较通道
>高级定时器的前3个通道额外拥有死区生成和互补输出的功能
二、PWM简介
>PWM（Pulse Width Modulation）脉冲宽度调制
>在具有惯性的系统中，可以通过对一系列脉冲的宽度进行调制，来等效地获得所需要的模拟参量，常应用于电机控速等领域
>PWM参数：
频率 = 1 / Ts 占空比 = Ton / Ts 分辨率 = 占空比变化步距
三、输出比较通道（通用）
四、输出比较通道（高级）
五、输出比较模式
六、PWM基本结构
七、PWM参数计算
八、外设介绍
8.1 舵机
8.2 直流电机及驱动
九、开发步骤
①RCC打开时钟，TIM和GPIO外设的时钟打开
②配置时基单元，包括前面的时钟源选择
③结构体配置输出比较单元（CCR，输出比较模式，极性选择，输出使能）
④配置GPIO，PWM对应GPIO初始化为复用推挽输出
⑤运行控制，启动计数器
十、输出比较库函数
注：标@的为重要，需掌握
@===================输出比较4模块配置函数==============================
void TIM_OC1Init(TIM_TypeDef* TIMx, TIM_OCInitTypeDef* TIM_OCInitStruct);
void TIM_OC2Init(TIM_TypeDef* TIMx, TIM_OCInitTypeDef* TIM_OCInitStruct);
void TIM_OC3Init(TIM_TypeDef* TIMx, TIM_OCInitTypeDef* TIM_OCInitStruct);
void TIM_OC4Init(TIM_TypeDef* TIMx, TIM_OCInitTypeDef* TIM_OCInitStruct);参数：①定时器；②结构体
=====================================================================
void TIM_OCStructInit(TIM_OCInitTypeDef* TIM_OCInitStruct);
//输出比较结构体赋初值
=====================配置强制输出模式（了解即可）========================
void TIM_ForcedOC1Config(TIM_TypeDef* TIMx, uint16_t TIM_ForcedAction);
void TIM_ForcedOC2Config(TIM_TypeDef* TIMx, uint16_t TIM_ForcedAction);
void TIM_ForcedOC3Config(TIM_TypeDef* TIMx, uint16_t TIM_ForcedAction);
void TIM_ForcedOC4Config(TIM_TypeDef* TIMx, uint16_t TIM_ForcedAction);=============配置CCR寄存器的预装功能（影子寄存器）（了解即可）=============
void TIM_OC1PreloadConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCPreload);
void TIM_OC2PreloadConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCPreload);
void TIM_OC3PreloadConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCPreload);
void TIM_OC4PreloadConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCPreload);=======================配置快速使能（了解即可）==========================
void TIM_OC1FastConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCFast);
void TIM_OC2FastConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCFast);
void TIM_OC3FastConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCFast);
void TIM_OC4FastConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCFast);=======================外部事件清除REF信号（了解即可）===================
void TIM_ClearOC1Ref(TIM_TypeDef* TIMx, uint16_t TIM_OCClear);
void TIM_ClearOC2Ref(TIM_TypeDef* TIMx, uint16_t TIM_OCClear);
void TIM_ClearOC3Ref(TIM_TypeDef* TIMx, uint16_t TIM_OCClear);
void TIM_ClearOC4Ref(TIM_TypeDef* TIMx, uint16_t TIM_OCClear);=======================单独设置输出比较极性=============================
void TIM_OC1PolarityConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCPolarity);
void TIM_OC1NPolarityConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCNPolarity);//N高级定时器互补通道的配置
void TIM_OC2PolarityConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCPolarity);
void TIM_OC2NPolarityConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCNPolarity);
void TIM_OC3PolarityConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCPolarity);
void TIM_OC3NPolarityConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCNPolarity);
void TIM_OC4PolarityConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCPolarity);=======================单独修改输出使能参数=============================
void TIM_CCxCmd(TIM_TypeDef* TIMx, uint16_t TIM_Channel, uint16_t TIM_CCx);
void TIM_CCxNCmd(TIM_TypeDef* TIMx, uint16_t TIM_Channel, uint16_t TIM_CCxN);=======================单独更改输出比较模式=============================
void TIM_SelectOCxM(TIM_TypeDef* TIMx, uint16_t TIM_Channel, uint16_t TIM_OCMode);
@=====================单独更改CCR寄存器值=============================
void TIM_SetCompare1(TIM_TypeDef* TIMx, uint16_t Compare1);
void TIM_SetCompare2(TIM_TypeDef* TIMx, uint16_t Compare2);
void TIM_SetCompare3(TIM_TypeDef* TIMx, uint16_t Compare3);
void TIM_SetCompare4(TIM_TypeDef* TIMx, uint16_t Compare4);==========================补充========================================
void TIM_CtrlPWMOutputs(TIM_TypeDef* TIMx, FunctionalState NewState);
//仅高级定时器使用，在使用高级定时器输出PWM时，需要调用这个函数，使能主输出，否则PWM将不能正常输出
十一、实验
9.1 PWM驱动LED呼吸灯
PWM.c
#include "stm32f10x.h" // Device header/*PWM初始化*/ void PWM_Init(void) {/*一、RCC开启时钟，TIM与GPIO时钟打开*/RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE);RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);// /*使用重映射(*_*)*/ // RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE); // GPIO_PinRemapConfig(GPIO_PartialRemap1_TIM2,ENABLE);//PA0->PA15，部分重映射S // GPIO_PinRemapConfig(GPIO_Remap_SWJ_JTAGDisable,ENABLE);//解除JATG调试GPIO_InitTypeDef GPIO_InitStructure;GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;//复用推挽输出GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;//(*_*)GPIO_Pin_15GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOA,&GPIO_InitStructure);/*二、配置时基单元（时钟源选择和时基单元配置）*/TIM_InternalClockConfig(TIM2);//选择内部时钟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自动重装器值TIM_TimeBaseInitStructure.TIM_Prescaler = 720 - 1; //PSC预分频器值TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;//重复计数器值TIM_TimeBaseInit(TIM2, &TIM_TimeBaseInitStructure);/*三、配置输出比较单元（CCR的值(捕获/比较器)，输出比较模式，极性选择，输出使能）*/TIM_OCInitTypeDef TIM_OCInitStructure;TIM_OCStructInit(&TIM_OCInitStructure);//给结构体所有成员赋初始值（有些用不到但是必须赋值）TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;//输出比较模式TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;//输出比较的极性TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;//输出使能TIM_OCInitStructure.TIM_Pulse = 0;//设置CCRTIM_OC1Init(TIM2,&TIM_OCInitStructure);/*四、配置GPIO，复用推挽输出*///一处已操作/*五、运行控制，启动计数器CNT*/TIM_Cmd(TIM2,ENABLE); }/*封装函数->更改CCR值来改变占空比*/ void PWM_SetCompare1(uint16_t Compare) {TIM_SetCompare1(TIM2,Compare); }PWM.h
#ifndef __PWM_H #define __PWM_Hvoid PWM_Init(void); void PWM_SetCompare1(uint16_t Compare);#endifmain.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){//CCR增大，逐渐变亮for (i = 0; i <= 100; i++){PWM_SetCompare1(i);Delay_ms(10);}//CCR减小，逐渐变暗for (i = 0; i <= 100; i++){PWM_SetCompare1(100 - i);Delay_ms(10);}} }
9.2 PWM驱动舵机
实验现象：按下按键，舵机转动固定角度
PWM.c
#include "stm32f10x.h" // Device header/*PWM初始化*/ void PWM_Init(void) {/*一、RCC开启时钟，TIM与GPIO时钟打开*/RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE);RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);GPIO_InitTypeDef GPIO_InitStructure;GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;//复用推挽输出GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOA,&GPIO_InitStructure);/*二、配置时基单元（时钟源选择和时基单元配置）*/TIM_InternalClockConfig(TIM2);//选择内部时钟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自动重装器值TIM_TimeBaseInitStructure.TIM_Prescaler = 72 - 1; //PSC预分频器值TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;//重复计数器值TIM_TimeBaseInit(TIM2, &TIM_TimeBaseInitStructure);/*三、配置输出比较单元（CCR的值(捕获/比较器)，输出比较模式，极性选择，输出使能）*/TIM_OCInitTypeDef TIM_OCInitStructure;TIM_OCStructInit(&TIM_OCInitStructure);//给结构体所有成员赋初始值（有些用不到但是必须赋值）TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;//输出比较模式TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;//输出比较的极性TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;//输出使能TIM_OCInitStructure.TIM_Pulse = 0;//设置CCR（500~2500）TIM_OC2Init(TIM2,&TIM_OCInitStructure);/*四、配置GPIO，复用推挽输出*///一处已操作/*五、运行控制，启动计数器CNT*/TIM_Cmd(TIM2,ENABLE); }/*封装函数->更改CCR值来改变占空比*/ void PWM_SetCompare2(uint16_t Compare) {TIM_SetCompare2(TIM2,Compare); }PWM.h
#ifndef __PWM_H #define __PWM_Hvoid PWM_Init(void); void PWM_SetCompare2(uint16_t Compare);#endifServo.c
#include "stm32f10x.h" // Device header #include "PWM.h"//舵机初始化（PWM初始化） void Servo_Init(void) {PWM_Init(); }/* 舵机设置角度 角度：0-180 CCR：500-2500 */ void Servo_SetAngle(float Angle) {PWM_SetCompare2(Angle / 180 * 2000 + 500); }Servo.h
#ifndef __SERVO_H #define __SERVO_Hvoid Servo_Init(void); void Servo_SetAngle(float Angle);#endifKey.c
#include "stm32f10x.h" // Device header #include "Delay.h"//===按键初始化===// void Key_Init(void) {RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB,ENABLE);GPIO_InitTypeDef GPIO_InitStructure;GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;//上拉输入GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1 | GPIO_Pin_11;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOB,&GPIO_InitStructure); }//===获取按键返回码===// uint8_t Key_GetNum(void) {uint8_t KeyNum = 0;if(GPIO_ReadInputDataBit(GPIOB,GPIO_Pin_1) == 0){Delay_ms(20);//消抖while(GPIO_ReadInputDataBit(GPIOB,GPIO_Pin_1) == 0);//如果不松手则卡着Delay_ms(20);KeyNum = 1;} if(GPIO_ReadInputDataBit(GPIOB,GPIO_Pin_11) == 0){Delay_ms(20);//消抖while(GPIO_ReadInputDataBit(GPIOB,GPIO_Pin_11) == 0);Delay_ms(20);KeyNum = 2;}return KeyNum; }key.h
#ifndef __KEY_H #define __KEY_Hvoid Key_Init(void); uint8_t Key_GetNum(void);#endifmain.c
#include "stm32f10x.h" // Device header #include "Delay.h" #include "OLED.h" #include "key.h" #include "Servo.h"uint8_t KeyNum; float Angle;int main(void) {OLED_Init();Key_Init();Servo_Init();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);} }*OLED显示屏代码请参考本专栏文章STM32-OLED显示屏
9.3 PWM驱动直流电机
实验现象： 按键按下，电机加速，达到最大转速时，再按一下，最大速度反转，按下按键，电机减速
PWM.c
#include "stm32f10x.h" // Device header/*PWM初始化*/ void PWM_Init(void) {/*一、RCC开启时钟，TIM与GPIO时钟打开*/RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE);RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);GPIO_InitTypeDef GPIO_InitStructure;GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;//复用推挽输出GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOA,&GPIO_InitStructure);/*二、配置时基单元（时钟源选择和时基单元配置）*/TIM_InternalClockConfig(TIM2);//选择内部时钟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自动重装器值TIM_TimeBaseInitStructure.TIM_Prescaler = 36 - 1; //PSC预分频器值TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;//重复计数器值TIM_TimeBaseInit(TIM2, &TIM_TimeBaseInitStructure);/*三、配置输出比较单元（CCR的值(捕获/比较器)，输出比较模式，极性选择，输出使能）*/TIM_OCInitTypeDef TIM_OCInitStructure;TIM_OCStructInit(&TIM_OCInitStructure);//给结构体所有成员赋初始值（有些用不到但是必须赋值）TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;//输出比较模式TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;//输出比较的极性TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;//输出使能TIM_OCInitStructure.TIM_Pulse = 0;//设置CCRTIM_OC3Init(TIM2,&TIM_OCInitStructure);/*四、配置GPIO，复用推挽输出*///一处已操作/*五、运行控制，启动计数器CNT*/TIM_Cmd(TIM2,ENABLE); }/*封装函数->更改CCR值来改变占空比*/ void PWM_SetCompare3(uint16_t Compare) {TIM_SetCompare3(TIM2,Compare); }PWM.h
#ifndef __PWM_H #define __PWM_Hvoid PWM_Init(void); void PWM_SetCompare3(uint16_t Compare);#endifMotor.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(); }/*设置电机速度（-100~100）*/ void Motor_SetSpeed(int8_t Speed) {if(Speed >= 0){GPIO_SetBits(GPIOA,GPIO_Pin_4);GPIO_ResetBits(GPIOA,GPIO_Pin_5);PWM_SetCompare3(Speed);}else{GPIO_SetBits(GPIOA,GPIO_Pin_5);GPIO_ResetBits(GPIOA,GPIO_Pin_4);PWM_SetCompare3(-Speed);} }Motor.h
#ifndef __PWM_H #define __PWM_Hvoid Motor_Init(void); void Motor_SetSpeed(int8_t Speed);#endif*按键与OLED显示屏的代码参考之前实验代码
