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STM32
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TIM1 是 STM32 的高级定时器，功能很强大，它的每个通道都有对应的互补通道用来互补输出PWM。之前没使用过，今天要用来做 PWM 控制，花了好一番功夫才搞定。 记录下初始化代码： void Led_PWM_Init(u16 arr, u32 ckCnt, u16 CCR1_Val) { uint16_t pscValue = 0; TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; TIM_OCInitTypeDef TIM_OCInitStructure; NVIC_InitTypeDef NVIC_InitStructure; RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE); GPIO_Config(); //PWM控制引脚初始化 TIM_DeInit(TIM1); /* Time Base configuration */ pscValue = (uint16_t)(SystemCoreClock / ckCnt) - 1; TIM_TimeBaseStructure.TIM_Prescaler = pscValue ; TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; TIM_TimeBaseStructure.TIM_Period = arr; TIM_TimeBaseStructure.TIM_ClockDivision = 0; TIM_TimeBaseStructure.TIM_RepetitionCounter = 0; //高级定时器特有 TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure); /* Channel 1, 2,3 and 4 Configuration in PWM mode */ TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Disable; // TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Reset; TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable; TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High; TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCNIdleState_Set; TIM_OCInitStructure.TIM_Pulse = CCR1_Val; //占空比 TIM_OC1Init(TIM1, &TIM_OCInitStructure); TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable); TIM_ARRPreloadConfig(TIM1, ENABLE); TIM_CtrlPWMOutputs(TIM1, ENABLE); TIM_Cmd(TIM1, ENABLE); }高级定时器做PWM的话和其他定时器一样的使用。只是配置不一样。 对于高级定时器来说，要有这句TIM_CtrlPWMOutputs(TIM1, ENABLE);使能PWM输出。 由于只是使用TIM1的通道1的互补通道，所以关闭通道1的 PWM 输出 TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Disable;打开通道1的互补通道的PWM的输出 TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;百度和对照别人的代码，搞了好久也没搞定不能控制亮度。后来发现是没有这句 TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Reset;上面这句要和下面这句设置相反： 一个是TIM_OCIdleState_Reset、另一个是TIM_OCNIdleState_Set TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCNIdleState_Set;
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