STM32F103使用TIM3定时器输出两路PWM控制直流电机

1、首先打开PWM输出实验例程（这里采用正点原子精英版例程），打开led.c,对相关端口进行修改
void LED_Init(void)
{

GPIO_InitTypeDef GPIO_InitStructure;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB|RCC_APB2Periph_GPIOE, ENABLE); //使能PB,PE端口时钟

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0|GPIO_Pin_2|GPIO_Pin_6|GPIO_Pin_5|GPIO_Pin_7|GPIO_Pin_9; //设置IO口，使用 //PB.5,PB.0作为PWM输出口，
//PB.2 PB.6,PB.7,PB.9作为电机输出信号口
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP; //推挽输出
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //IO口速度为50MHz
GPIO_Init(GPIOB, &GPIO_InitStructure); //根据设定参数初始化GPIOB.5
GPIO_SetBits(GPIOB,GPIO_Pin_0|GPIO_Pin_5); //PB.5 输出高
GPIO_ResetBits(GPIOB,GPIO_Pin_2|GPIO_Pin_6|GPIO_Pin_7|GPIO_Pin_9);

// GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5; //LED1-->PE.5 端口配置, 推挽输出
// GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPD; //推挽输出
//GPIO_Init(GPIOE, &GPIO_InitStructure); //推挽输出，IO口速度为50MHz
//GPIO_SetBits(GPIOE,GPIO_Pin_5); //PE.5 输出高
}

2、在led.h中定义输出IO口
#ifndef __LED_H
#define __LED_H
#include "sys.h"
#define ENA PBout(5)// PB5
#define IN1 PBout(2)
#define IN2 PBout(6)

#define ENB PBout(0)//PB0
#define IN3 PBout(7)
#define IN4 PBout(9)

#define LED1 PEout(5)// PE5

void LED_Init(void);//初始化

#endif

3、打开timer.c，对pwm初始化函数进行修改
//TIM3 PWM部分初始化
//PWM输出初始化
//arr：自动重装值
//psc：时钟预分频数
void TIM3_PWM_Init(u16 arr,u16 psc)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); //使能定时器3时钟
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE); //使能GPIO外设和AFIO复用功能模块时钟

GPIO_PinRemapConfig(GPIO_PartialRemap_TIM3, ENABLE); //Timer3部分重映射 TIM3_CH2->PB5

//设置该引脚为复用输出功能,输出TIM3 CH2的PWM脉冲波形 GPIOB.5
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5; //TIM_CH2
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //复用推挽输出
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &GPIO_InitStructure);//初始化GPIO

// GPIO_PinRemapConfig(GPIO_PartialRemap_TIM3, ENABLE);
//设置该引脚为复用输出功能,输出TIM3 CH3的PWM脉冲波形 GPIOB.0
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0; //TIM_CH3
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //复用推挽输出
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &GPIO_InitStructure);//初始化GPIO

//初始化TIM3
TIM_TimeBaseStructure.TIM_Period = arr; //设置在下一个更新事件装入活动的自动重装载寄存器周期的值
TIM_TimeBaseStructure.TIM_Prescaler =psc; //设置用来作为TIMx时钟频率除数的预分频值
TIM_TimeBaseStructure.TIM_ClockDivision = 0; //设置时钟分割:TDTS = Tck_tim
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM向上计数模式
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); //根据TIM_TimeBaseInitStruct中指定的参数初始化TIMx的时间基数单位

//初始化TIM3 Channel2 PWM模式
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //选择定时器模式:TIM脉冲宽度调制模式2
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //比较输出使能
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //输出极性:TIM输出比较极性高
TIM_OC2Init(TIM3, &TIM_OCInitStructure); //根据T指定的参数初始化外设TIM3 OC2
TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable); //使能TIM3在CCR2上的预装载寄存器

//初始化TIM3 Channel2 PWM模式
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //选择定时器模式:TIM脉冲宽度调制模式2
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //比较输出使能
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //输出极性:TIM输出比较极性高
TIM_OC3Init(TIM3, &TIM_OCInitStructure); //根据T指定的参数初始化外设TIM3 OC3
TIM_OC3PreloadConfig(TIM3, TIM_OCPreload_Enable);

TIM_Cmd(TIM3, ENABLE); //使能TIM3

}

4、最后在主函数进行操作，将PB.5和PB.0接L298N的ENA和ENB，IN1,IN2接PB.2和PB.6,IN3,IN4接PB.7和PB.9
(我这里是通过按键KEY1进行加速，KEY_UP进行转动方向的改变，具体需要什么功能可自行设置)
int main(void)
{
u16 pwmval;
u8 dir=1;
u8 key,m1,m2;
delay_init(); //延时函数初始化
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2); //设置NVIC中断分组2:2位抢占优先级，2位响应优先级
uart_init(115200); //串口初始化为115200
LED_Init(); //LED端口初始化
KEY_Init();
TIM3_PWM_Init(899,0); //不分频。PWM频率=72000000/900=80Khz
pwmval = 0;
m1 = 0;
m2 = 1;
while(1)
{

key = KEY_Scan(0);
if(key == KEY1_PRES)
{
pwmval -= 50;
}
if(key == WKUP_PRES)
{
pwmval = 350;
m1 = ~m1;
m2 = ~m2;
}

delay_ms(10);
TIM_SetCompare2(TIM3,pwmval);
TIM_SetCompare3(TIM3,pwmval);
IN1 = m1;
IN2 = m2;
IN3 = m1;
IN4 = m2;
}
}