硬件連接：戰(zhàn)艦STM32F103ZET6或其他

實(shí)驗(yàn)?zāi)繕?biāo)：通過調(diào)制占空比調(diào)節(jié)多路PWM控制LED的明暗；

#include "pwm.h"

#include "led.h"

//PWM輸出初始化

//arr：自動(dòng)重裝值

//psc：時(shí)鐘預(yù)分頻數(shù)

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);//

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA|RCC_APB2Periph_GPIOB , ENABLE); //使能GPIO外設(shè)時(shí)鐘使能

//設(shè)置該引腳為復(fù)用輸出功能,輸出TIM1 CH1的PWM脈沖波形

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //復(fù)用推挽輸出

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_Init(GPIOA, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0|GPIO_Pin_1 ; //TIM_CH1

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //復(fù)用推挽輸出

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_Init(GPIOB, &GPIO_InitStructure);

TIM_TimeBaseStructure.TIM_Period = arr; //設(shè)置在下一個(gè)更新事件裝入活動(dòng)的自動(dòng)重裝載寄存器周期的值 80K

TIM_TimeBaseStructure.TIM_Prescaler =psc; //設(shè)置用來作為TIMx時(shí)鐘頻率除數(shù)的預(yù)分頻值 不分頻

TIM_TimeBaseStructure.TIM_ClockDivision =0; //設(shè)置時(shí)鐘分割:TDTS = Tck_tim

TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM向上計(jì)數(shù)模式

TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); //根據(jù)TIM_TimeBaseInitStruct中指定的參數(shù)初始化TIMx的時(shí)間基數(shù)單位

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //選擇定時(shí)器模式:TIM脈沖寬度調(diào)制模式2

TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //比較輸出使能

TIM_OCInitStructure.TIM_Pulse = 300; //設(shè)置待裝入捕獲比較寄存器的脈沖值

TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //輸出極性:TIM輸出比較極性高

TIM_OC1Init(TIM3, &TIM_OCInitStructure); //根據(jù)TIM_OCInitStruct中指定的參數(shù)初始化外設(shè)TIMx

TIM_OCInitStructure.TIM_OutputState =TIM_OutputState_Enable;

TIM_OCInitStructure.TIM_Pulse = 150;

TIM_OC2Init(TIM3, &TIM_OCInitStructure);

TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable);

TIM_OCInitStructure.TIM_OutputState =TIM_OutputState_Enable;

TIM_OCInitStructure.TIM_Pulse = 150;

TIM_OC3Init(TIM3, &TIM_OCInitStructure);

TIM_OC3PreloadConfig(TIM3, TIM_OCPreload_Enable);

TIM_OCInitStructure.TIM_OutputState =TIM_OutputState_Enable;

TIM_OCInitStructure.TIM_Pulse = 150;

TIM_OC4Init(TIM3, &TIM_OCInitStructure);

TIM_OC4PreloadConfig(TIM3, TIM_OCPreload_Enable);

TIM_CtrlPWMOutputs(TIM3,ENABLE); //MOE 主輸出使能

TIM_ARRPreloadConfig(TIM3, ENABLE); //使能TIMx在ARR上的預(yù)裝載寄存器

TIM_Cmd(TIM3, ENABLE); //使能TIM1

}

.#include "led.h"

#include "delay.h"

#include "sys.h"

#include "pwm.h"

int main(void)

{

u16 led0pwmval=150;

u16 led1pwmval=150;

u16 led2pwmval=150;

u16 led3pwmval=150;

u8 dir=1;

u16 math=0;

delay_init(); //延時(shí)函數(shù)初始化

LED_Init(); //初始化與LED連接的硬件接口

TIM3_PWM_Init(899,0);//不分頻。PWM頻率=72000/(899+1)=80Khz

while(1)

{

delay_ms(10);

math++;

if(math)

{

delay_ms(10);

if(dir)

{led0pwmval++;led1pwmval++;led2pwmval++;led3pwmval++;}

else {led0pwmval--;led1pwmval--;led2pwmval--;led3pwmval--;}

if(led0pwmval>600||led1pwmval>600||led2pwmval>600||led3pwmval>600) dir=0;

if(led0pwmval==0||led1pwmval==0||led2pwmval==0||led3pwmval==0) dir=1;

math=0;

}

TIM_SetCompare1(TIM3,led0pwmval);

TIM_SetCompare2(TIM3,led1pwmval);

TIM_SetCompare3(TIM3,led2pwmval);

TIM_SetCompare4(TIM3,led3pwmval);

}

}

方法二：

void PWM_Configuration(void)//PWM初始化函數(shù)

{

TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;//定時(shí)器初始化結(jié)構(gòu)

TIM_OCInitTypeDef TIM_OCInitStructure;//通道輸出初始化結(jié)構(gòu)

GPIO_InitTypeDefGPIO_InitStructure;//輸出通道的GPIO管腳結(jié)構(gòu)

//(1)TIM3初始化,時(shí)間基部分

TIM_TimeBaseStructure.TIM_Period=（1000-1）; //周期0～999

TIM_TimeBaseStructure.TIM_Prescaler =（72-1）; //時(shí)鐘分頻

TIM_TimeBaseStructure.TIM_ClockDivision =TIM_CKD_DIV1; //時(shí)鐘分割

TIM_TimeBaseStructure.TIM_CounterMode =TIM_CounterMode_Up;//向上計(jì)數(shù)模式

TIM_TimeBaseInit(TIM3,&TIM_TimeBaseStructure); //初始化

//TIM_ITConfig(TIM3, TIM_IT_CC4,ENABLE); //打開中斷，中斷需要這行代碼

//(2)TIM3通道初始化 ，CCP部分

TIM_OCStructInit(&TIM_OCInitStructure); //默認(rèn)參數(shù)

TIM_OCInitStructure.TIM_OCMode =TIM_OCMode_PWM1; //工作狀態(tài)

TIM_OCInitStructure.TIM_OutputState =TIM_OutputState_Enable; //設(shè)定為輸出，需要PWM輸出才需要這行代碼

TIM_OCInitStructure.TIM_Pulse =250; //占空長度

TIM_OCInitStructure.TIM_OCPolarity =TIM_OCPolarity_High; //高電平

TIM_OC4Init(TIM3,&TIM_OCInitStructure); //通道初始化

TIM_OCInitStructure.TIM_OCMode =TIM_OCMode_PWM1; //工作狀態(tài)

TIM_OCInitStructure.TIM_OutputState =TIM_OutputState_Enable; //設(shè)定為輸出，需要PWM輸出才需要這行代碼

TIM_OCInitStructure.TIM_Pulse =500; //占空長度

TIM_OCInitStructure.TIM_OCPolarity =TIM_OCPolarity_High; //高電平

TIM_OC3Init(TIM3,&TIM_OCInitStructure); //通道初始化

TIM_OC3Init(TIM3, &TIM_OCInitStructure);

TIM_OCInitStructure.TIM_OCMode =TIM_OCMode_PWM1; //工作狀態(tài)

TIM_OCInitStructure.TIM_OutputState =TIM_OutputState_Enable; //設(shè)定為輸出，需要PWM輸出才需要這行代碼

TIM_OCInitStructure.TIM_Pulse =750; //占空長度

TIM_OCInitStructure.TIM_OCPolarity =TIM_OCPolarity_High; //高電平

TIM_OC2Init(TIM3, &TIM_OCInitStructure);

TIM_OCInitStructure.TIM_OCMode =TIM_OCMode_PWM1; //工作狀態(tài)

TIM_OCInitStructure.TIM_OutputState =TIM_OutputState_Enable; //設(shè)定為輸出，需要PWM輸出才需要這行代碼

TIM_OCInitStructure.TIM_Pulse =900; //占空長度