2018年06月29日 | stm32PWM精确控制脉冲个数

/****************************

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**TIM2的通道1使用单脉冲模式

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**TIM3使用门控模式用来输出PWM

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**

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****************************/

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//TIM2per:重装值

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//Compare1:比较捕获1的预装载值

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void Motor_Init(u16 TIM2per, u16 TIM3per, u16 TIM3Compare1)

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{

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  TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStruct;

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  TIM_OCInitTypeDef TIM_OCInitStruct;

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  GPIO_InitTypeDef GPIO_InitStruct;

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  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE);//使能定时器2的时钟

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  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3,ENABLE);//使能定时器3的时钟

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  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);//使能GPIOA时钟

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  RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);//使能复用IO时钟

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  GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF_PP;//复用推挽输出

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  GPIO_InitStruct.GPIO_Pin = GPIO_Pin_0|GPIO_Pin_6;//PA0

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  GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;

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  GPIO_Init(GPIOA,&GPIO_InitStruct);

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  //TIM2工作在单脉冲下

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  TIM_TimeBaseInitStruct.TIM_ClockDivision = TIM_CKD_DIV1;//没有时钟分割

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  TIM_TimeBaseInitStruct.TIM_CounterMode = TIM_CounterMode_Up;//向上计数模式

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  TIM_TimeBaseInitStruct.TIM_Prescaler = 7200;//预分频值,每100us计数一次

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  TIM_TimeBaseInitStruct.TIM_Period = TIM2per;//重装值

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  TIM_TimeBaseInit(TIM2,&TIM_TimeBaseInitStruct);

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  TIM_SelectOnePulseMode(TIM2,TIM_OPMode_Single);//设置TIM2在单脉冲模式，且是单一的脉冲，在下一个更新事件停止

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  TIM_OC1PreloadConfig(TIM2,TIM_OCPreload_Enable);//使能定时器2的通道1预装载寄存器

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  TIM_SelectOutputTrigger(TIM2,TIM_TRGOSource_OC1Ref);

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  TIM_OCInitStruct.TIM_OCMode = TIM_OCMode_PWM2;//在向上计数时，一旦TIMx_CNT

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  TIM_OCInitStruct.TIM_OutputState = TIM_OutputState_Enable;//OC1输出使能

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  TIM_OCInitStruct.TIM_OCPolarity = TIM_OCPolarity_High;//有效电平为高

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  TIM_OCInitStruct.TIM_Pulse = 1;//比较捕获1的预装载值

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  TIM_OC1Init(TIM2,&TIM_OCInitStruct);

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  TIM_Cmd(TIM2,DISABLE);//先不使能能TIM2

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  //TIM3工作在从模式的门控模式下的PWM输出模式

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  TIM_TimeBaseInitStruct.TIM_ClockDivision = TIM_CKD_DIV1;//没有时钟分割

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  TIM_TimeBaseInitStruct.TIM_CounterMode = TIM_CounterMode_Up;//向上计数模式

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  TIM_TimeBaseInitStruct.TIM_Prescaler = 720;//预分频值，10us计数一次

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  TIM_TimeBaseInitStruct.TIM_Period = TIM3per;//重装值

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  TIM_TimeBaseInit(TIM3,&TIM_TimeBaseInitStruct);

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  TIM_SelectSlaveMode(TIM3, TIM_SlaveMode_Gated);//TIM3为门控模式

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  TIM_SelectMasterSlaveMode(TIM3,TIM_MasterSlaveMode_Enable);//使能TIM3的主从模式

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  TIM_SelectInputTrigger(TIM3,TIM_TS_ITR1);//内部触发，从TIM2触发

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  TIM_OCInitStruct.TIM_OCMode = TIM_OCMode_PWM2;//在向上计数时，一旦TIMx_CNT

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  TIM_OCInitStruct.TIM_OutputState = TIM_OutputState_Enable;//OC1输出使能

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  TIM_OCInitStruct.TIM_OCPolarity = TIM_OCPolarity_High;//有效电平为高

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  TIM_OCInitStruct.TIM_Pulse = TIM3Compare1;//比较捕获1的预装载值

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  TIM_OC1Init(TIM3,&TIM_OCInitStruct);

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  TIM_Cmd(TIM3,ENABLE);//使能TIM3

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}

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//设置PWM的输出

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//Cycle:为周期,单位(us)

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//Pulse_Num:为脉冲个数（小于3200）

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void TIM2_TIM3_PWM(u16 Cycle, u16 Pulse_Num)

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{

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  u16 TIM3per = 0;

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  u32 Time = 0;

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  //改变TIM3的重装值改变脉冲频率这里设置脉冲占空比为50%

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  //改变TIM2的预分频器和重装值改变脉冲个数

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  Time = Cycle * Pulse_Num;

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  Time /= 100;              //预分频为7200,100us计数一次

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  TIM3per = Cycle/10;       //预分频为720,10us计数一次

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  TIM_SetAutoreload(TIM2, Time+1);//设置TIM2的重装值

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  TIM_SetAutoreload(TIM3, TIM3per-1);//设置TIM3的重装值

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  TIM_SetCompare1(TIM3,TIM3per/2);//设置占空比为50%

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  TIM_Cmd(TIM2,ENABLE);//使能TIM2

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}