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给你参考一下~一样的~
#include "bsp_pwm_output.h"
/**
* @brief 配置TIM3复用输出PWM时用到的I/O
* @param 无
* @retval 无
*/
static void TIM3_GPIO_Config(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
/* 设置TIM3CLK 为 72MHZ */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
/* GPIOA and GPIOB clock enable */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB, ENABLE);
/*GPIOA Configuration: TIM3 channel 1 and 2 as alternate function push-pull */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; // 复用推挽输出
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
/*GPIOB Configuration: TIM3 channel 3 and 4 as alternate function push-pull */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1;
GPIO_Init(GPIOB, &GPIO_InitStructure);
}
/**
* @brief 配置TIM3输出的PWM信号的模式,如周期、极性、占空比
* @param 无
* @retval 无
*/
/*
* TIMxCLK/CK_PSC --> TIMxCNT --> TIMx_ARR --> TIMxCNT 重新计数
* TIMx_CCR(电平发生变化)
* 信号周期=(TIMx_ARR +1 ) * 时钟周期
* 占空比=TIMx_CCR/(TIMx_ARR +1)
*/
static void TIM3_Mode_Config(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
/* PWM信号电平跳变值 */
u16 CCR1_Val = 500;
u16 CCR2_Val = 375;
u16 CCR3_Val = 250;
u16 CCR4_Val = 125;
/* -----------------------------------------------------------------------
TIM3 Channel1 duty cycle = (TIM3_CCR1/ TIM3_ARR+1)* 100% = 50%
TIM3 Channel2 duty cycle = (TIM3_CCR2/ TIM3_ARR+1)* 100% = 37.5%
TIM3 Channel3 duty cycle = (TIM3_CCR3/ TIM3_ARR+1)* 100% = 25%
TIM3 Channel4 duty cycle = (TIM3_CCR4/ TIM3_ARR+1)* 100% = 12.5%
----------------------------------------------------------------------- */
/* Time base configuration */
TIM_TimeBaseStructure.TIM_Period = 999; //当定时器从0计数到999,即为1000次,为一个定时周期
TIM_TimeBaseStructure.TIM_Prescaler = 0; //设置预分频:不预分频,即为72MHz
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1 ; //设置时钟分频系数:不分频(这里用不到)
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //向上计数模式
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);
/* PWM1 Mode configuration: Channel1 */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //配置为PWM模式1
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR1_Val; //设置跳变值,当计数器计数到这个值时,电平发生跳变
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //当定时器计数值小于CCR1_Val时为高电平
TIM_OC1Init(TIM3, &TIM_OCInitStructure); //使能通道1
TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Enable);
/* PWM1 Mode configuration: Channel2 */
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR2_Val; //设置通道2的电平跳变值,输出另外一个占空比的PWM
TIM_OC2Init(TIM3, &TIM_OCInitStructure); //使能通道2
TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable);
/* PWM1 Mode configuration: Channel3 */
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR3_Val; //设置通道3的电平跳变值,输出另外一个占空比的PWM
TIM_OC3Init(TIM3, &TIM_OCInitStructure); //使能通道3
TIM_OC3PreloadConfig(TIM3, TIM_OCPreload_Enable);
/* PWM1 Mode configuration: Channel4 */
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR4_Val; //设置通道4的电平跳变值,输出另外一个占空比的PWM
TIM_OC4Init(TIM3, &TIM_OCInitStructure); //使能通道4
TIM_OC4PreloadConfig(TIM3, TIM_OCPreload_Enable);
TIM_ARRPreloadConfig(TIM3, ENABLE); // 使能TIM3重载寄存器ARR
/* TIM3 enable counter */
TIM_Cmd(TIM3, ENABLE); //使能定时器3
}
/**
* @brief TIM3 输出PWM信号初始化,只要调用这个函数
* TIM3的四个通道就会有PWM信号输出
* @param 无
* @retval 无
*/
void TIM3_PWM_Init(void)
{
TIM3_GPIO_Config();
TIM3_Mode_Config();
}
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