PWM输出配置步骤:(举例)
① 使能定时器3和相关IO口时钟。
使能定时器3时钟:RCC_APB1PeriphClockCmd();
使能GPIOB时钟:RCC_APB2PeriphClockCmd();
② 初始化IO口为复用功能输出。函数:GPIO_Init();
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
③这里我们是要把PB5用作定时器的PWM输出引脚,所以要重映射配置,
所以需要开启AFIO时钟。同时设置重映射。
RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);
GPIO_PinRemapConfig(GPIO_PartialRemap_TIM3, ENABLE);
④ 初始化定时器:ARR,PSC等:TIM_TimeBaseInit();
⑤ 初始化输出比较参数:TIM_OC2Init();
⑥ 使能预装载寄存器: TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable);
⑦ 使能定时器。TIM_Cmd();
⑧ 不断改变比较值CCRx,达到不同的占空比效果:TIM_SetCompare2();
源代码:双路输出互补PWM
#include "pwm.h"
#include "led.h"
//
// ÅàÉÙ
//All rights reserved
//
//PWMÊä³ö˫·»¥²¹
//arr£º×Ô¶¯ÖØ×°Öµ
//psc£ºÊ±ÖÓÔ¤·ÖƵÊý
void TIM1_PWM_Init(u16 arr,u16 psc)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);//
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA , ENABLE); //ʹÄÜGPIOÍâÉèʱÖÓʹÄÜ
//ÉèÖøÃÒý½ÅΪ¸´ÓÃÊä³ö¹¦ÄÜ,Êä³öTIM1 CH1µÄPWMÂö³å²¨ÐÎ
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8; //TIM_CH1
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //¸´ÓÃÍÆÍìÊä³ö
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11; //TIM_CH4
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //¸´ÓÃÍÆÍìÊä³ö
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
TIM_TimeBaseStructure.TIM_Period = arr; //ÉèÖÃÔÚÏÂÒ»¸ö¸üÐÂʼþ×°Èë»î¶¯µÄ×Ô¶¯ÖØ×°ÔؼĴæÆ÷ÖÜÆÚµÄÖµ 80K
TIM_TimeBaseStructure.TIM_Prescaler =psc; //ÉèÖÃÓÃÀ´×÷ΪTIMxʱÖÓƵÂʳýÊýµÄÔ¤·ÖƵֵ ²»·ÖƵ
TIM_TimeBaseStructure.TIM_ClockDivision = 0; //ÉèÖÃʱÖÓ·Ö¸î:TDTS = Tck_tim
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIMÏòÉϼÆÊýģʽ
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure); //¸ù¾ÝTIM_TimeBaseInitStructÖÐÖ¸¶¨µÄ²ÎÊý³õʼ»¯TIMxµÄʱ¼ä»ùÊýµ¥Î»
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //Ñ¡Ôñ¶¨Ê±Æ÷ģʽ:TIMÂö³å¿í¶Èµ÷ÖÆģʽ2
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //±È½ÏÊä³öʹÄÜ
TIM_OCInitStructure.TIM_Pulse = 0; //ÉèÖôý×°È벶»ñ±È½Ï¼Ä´æÆ÷µÄÂö³åÖµ
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //Êä³ö¼«ÐÔ:TIMÊä³ö±È½Ï¼«ÐÔ¸ß
TIM_OC1Init(TIM1, &TIM_OCInitStructure); //¸ù¾ÝTIM_OCInitStructÖÐÖ¸¶¨µÄ²ÎÊý³õʼ»¯ÍâÉèTIMx
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //Ñ¡Ôñ¶¨Ê±Æ÷ģʽ:TIMÂö³å¿í¶Èµ÷ÖÆģʽ1Óë2»¥²¹
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //±È½ÏÊä³öʹÄÜ
TIM_OCInitStructure.TIM_Pulse = 0; //ÉèÖôý×°È벶»ñ±È½Ï¼Ä´æÆ÷µÄÂö³åÖµ
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //Êä³ö¼«ÐÔ:TIMÊä³ö±È½Ï¼«ÐÔ¸ß
TIM_OC4Init(TIM1, &TIM_OCInitStructure); //¸ù¾ÝTIM_OCInitStructÖÐÖ¸¶¨µÄ²ÎÊý³õʼ»¯ÍâÉèTIMx
TIM_CtrlPWMOutputs(TIM1,ENABLE); //MOE Ö÷Êä³öʹÄÜ
TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable); //CH1ԤװÔØʹÄÜ
TIM_OC4PreloadConfig(TIM1, TIM_OCPreload_Enable); //CH4ԤװÔØʹÄÜ
TIM_ARRPreloadConfig(TIM1, ENABLE); //ʹÄÜTIMxÔÚARRÉϵÄԤװÔؼĴæÆ÷
TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set; //???????1
TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset; //?????????0
TIM_Cmd(TIM1, ENABLE); //ʹÄÜTIM1
}
void TIM8_PWM_Init(u16 arr,u16 psc)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);//
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA , ENABLE); //ʹÄÜGPIOÍâÉèʱÖÓʹÄÜ
//ÉèÖøÃÒý½ÅΪ¸´ÓÃÊä³ö¹¦ÄÜ,Êä³öTIM1 CH1µÄPWMÂö³å²¨ÐÎ
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8; //TIM_CH1
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //¸´ÓÃÍÆÍìÊä³ö
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11; //TIM_CH4
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //¸´ÓÃÍÆÍìÊä³ö
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
TIM_TimeBaseStructure.TIM_Period = arr; //ÉèÖÃÔÚÏÂÒ»¸ö¸üÐÂʼþ×°Èë»î¶¯µÄ×Ô¶¯ÖØ×°ÔؼĴæÆ÷ÖÜÆÚµÄÖµ 80K
TIM_TimeBaseStructure.TIM_Prescaler =psc; //ÉèÖÃÓÃÀ´×÷ΪTIMxʱÖÓƵÂʳýÊýµÄÔ¤·ÖƵֵ ²»·ÖƵ
TIM_TimeBaseStructure.TIM_ClockDivision = 0; //ÉèÖÃʱÖÓ·Ö¸î:TDTS = Tck_tim
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIMÏòÉϼÆÊýģʽ
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure); //¸ù¾ÝTIM_TimeBaseInitStructÖÐÖ¸¶¨µÄ²ÎÊý³õʼ»¯TIMxµÄʱ¼ä»ùÊýµ¥Î»
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //Ñ¡Ôñ¶¨Ê±Æ÷ģʽ:TIMÂö³å¿í¶Èµ÷ÖÆģʽ2
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //±È½ÏÊä³öʹÄÜ
TIM_OCInitStructure.TIM_Pulse = 0; //ÉèÖôý×°È벶»ñ±È½Ï¼Ä´æÆ÷µÄÂö³åÖµ
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //Êä³ö¼«ÐÔ:TIMÊä³ö±È½Ï¼«ÐÔ¸ß
TIM_OC1Init(TIM1, &TIM_OCInitStructure); //¸ù¾ÝTIM_OCInitStructÖÐÖ¸¶¨µÄ²ÎÊý³õʼ»¯ÍâÉèTIMx
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //Ñ¡Ôñ¶¨Ê±Æ÷ģʽ:TIMÂö³å¿í¶Èµ÷ÖÆģʽ1Óë2»¥²¹
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //±È½ÏÊä³öʹÄÜ
TIM_OCInitStructure.TIM_Pulse = 0; //ÉèÖôý×°È벶»ñ±È½Ï¼Ä´æÆ÷µÄÂö³åÖµ
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //Êä³ö¼«ÐÔ:TIMÊä³ö±È½Ï¼«ÐÔ¸ß
TIM_OC4Init(TIM1, &TIM_OCInitStructure); //¸ù¾ÝTIM_OCInitStructÖÐÖ¸¶¨µÄ²ÎÊý³õʼ»¯ÍâÉèTIMx
TIM_CtrlPWMOutputs(TIM1,ENABLE); //MOE Ö÷Êä³öʹÄÜ
TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable); //CH1ԤװÔØʹÄÜ
TIM_OC4PreloadConfig(TIM1, TIM_OCPreload_Enable); //CH4ԤװÔØʹÄÜ
TIM_ARRPreloadConfig(TIM1, ENABLE); //ʹÄÜTIMxÔÚARRÉϵÄԤװÔؼĴæÆ÷
TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set; //???????1
TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset; //?????????0
TIM_Cmd(TIM1, ENABLE); //ʹÄÜTIM1
}
main.c文件
#include "led.h"
#include "delay.h"
#include "sys.h"
#include "pwm.h"
//ÅàÉÙ
//PWMÊä³öʵÑé
int main(void)
{
u16 led0pwmval=0;
u8 dir=1;
delay_init(); //ÑÓʱº¯Êý³õʼ»¯
LED_Init(); //³õʼ»¯ÓëLEDÁ¬½ÓµÄÓ²¼þ½Ó¿Ú
TIM1_PWM_Init(899,0);//²»·ÖƵ¡£PWMƵÂÊ=72000/(899+1)=80Khz
while(1)
{
delay_ms(10);
// if(dir)led0pwmval++;
// else led0pwmval--;
// if(led0pwmval=300)dir=0;
//if(led0pwmval==0)dir=1;
TIM_SetCompare1(TIM1,450);
TIM_SetCompare4(TIM1,450);
}
}