STM32设置PWM输出是时候少一下波形
- //配置成PWM输出
- void TIM3_Mode_Config(u16 f,u16 p)
- {
- TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;//初始化TIM3的时间基数单位
- TIM_OCInitTypeDef TIM_OCInitStructure;//初始化TIM3的外设
- NVIC_InitTypeDef NVIC_InitStructure;
- //打开TIM3的时钟
- RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
- //TIM3的时间基数单位设置(如计数终止值：999,从0开始 ；计数方式：向上计数）
- TIM_TimeBaseStructure.TIM_Prescaler= (48 - 1); //时钟预分频数,时钟频率=72MHZ/(时钟预分频+1) 之后是12M
- TIM_TimeBaseStructure.TIM_Period=STARTSPEED-1; //自动重装载寄存器的值/1ms 12KHZ
- TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1 ;
- TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
- TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);
- NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1); //优先级分组（0~4）, 抢占式为0，没嵌套
- NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn; //制定IRQ通道
- NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1; //先占优先级
- NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;//从优先级
- NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
- NVIC_Init(&NVIC_InitStructure);
-
- //TIM3的外设的设置
- TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //TIM脉冲宽度调制模式1
- TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;//这个暂时不知道，stm32固件库里没有搜到。应该是定时器输出声明使能的意思
- TIM_OCInitStructure.TIM_Pulse = STARTSPEED/2;//设置了待装入捕获比较寄存器的脉冲值
- TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low; //TIM输出比较极性高
- TIM_OC4Init(TIM3, &TIM_OCInitStructure);
-
- TIM_OC4PreloadConfig(TIM3, TIM_OCPreload_Enable);//使能或者失能TIMx在CCR1上的预装载寄存器
- TIM_ARRPreloadConfig(TIM3, ENABLE); //使能TIM3重载寄存器ARR
- TIM_ClearFlag(TIM3, TIM_FLAG_Update); //清除溢出中断标志
- //TIM_ITConfig(TIM3,TIM_IT_Update,ENABLE);
-
- TIM_Cmd(TIM3, ENABLE);//使能TIM3
-
- }
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