前言:stm32f103rct6晶片,TIM4_CH3 (PB8); 中斷内統計脈沖個數,如果介意中斷太多太頻繁占用cpu資源,或其他功能帶的比較多,此方法不是好方法。(最近寫這東西才發現認認真真看寄存器配置多重要,才有認認真真看stm32中文參考手冊)
用此(輸出比較模式)驅動步進電機轉動指定角度,以前用pwm模式寫過步進電機的加減速控制
一、通用定時器輸出比較模式
二、定時器初始化配置
//TIM4 PWM部分初始化
//PWM輸出初始化
//arr:自動重裝值
//psc:時鐘預分頻數
void TIM4_PWM_Init(u16 arr,u16 psc)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE);
TIM_TimeBaseStructInit(&TIM_TimeBaseStructure); //設定預設值,這一步最好加上
TIM_TimeBaseStructure.TIM_Period = arr; //自動重裝載寄存器周期的值,溢出值
TIM_TimeBaseStructure.TIM_Prescaler =psc; //時鐘頻率預分頻值
TIM_TimeBaseStructure.TIM_ClockDivision = 0; //設定時鐘分割,不分割,可不寫
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM向上計數模式
//TIM_TimeBaseStructure.TIM_RepetitionCounter=0; //設定重複溢出次數,就是多少次溢出後進入中斷,一般為0,隻有進階定時器才有用
TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &GPIO_InitStructure);
GPIO_ResetBits(GPIOB,GPIO_Pin_8); //當計數器CNT與CCRx比對時翻轉該引腳電平
TIM_OCStructInit(&TIM_OCInitStructure); //設定預設值,這一步最好加上
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle; //翻轉模式定時器引腳同時輸出pwm
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //比較輸出使能
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //輸出極性:TIM輸出比較極性高
TIM_OC3Init(TIM4, &TIM_OCInitStructure);
TIM_OC3PreloadConfig(TIM4, TIM_OCPreload_Enable);
//中斷分組初始化
NVIC_InitStructure.NVIC_IRQChannel = TIM4_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
TIM_ITConfig(TIM4, TIM_IT_CC3, ENABLE); //設定寄存器TIM4->DIER CC3IE位允許捕獲/比較3中斷;CC3DE位允許捕獲/比較3中斷的DMA請求
TIM_Cmd(TIM4,ENABLE); //啟動定時器3 TIM3_CR1[0]=1;
}
三、中斷處理函數
void TIM4_IRQHandler(void)
{
static u32 pulse = 0;
if (TIM_GetITStatus(TIM4, TIM_IT_CC3) != RESET)
{
TIM_ClearITPendingBit(TIM4,TIM_IT_CC3);
pulse++;
if(pulse > 12800)
{
TIM_Cmd(TIM4, DISABLE);
pulse = 0;
}
}
}
這裡設定的是12800脈沖,由于步進電機步距角為1.8度(即1個脈沖轉動1.8度),細分設定為64,則
64個脈沖轉動1.8度,360*64/1.8 = 12800脈沖