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为了得到更好得体验，我们本次主要是对定时器进行多重得体验，通过板载得两个LED灯结合按键进行多种展示功能切换。

首先了解一下CH32X035得定时器，高级定时器模块（ADTM）包含两个功能强大的16位自动重装定时器（TIM1/TIM2），可用于测量脉冲宽度或产生脉冲、PWM波等。用于电机控制、电源等领域；通用定时器模块包含一个16位可自动重装的定时器（TIM3），用于测量脉冲宽度或者产生特定频率的脉冲、PWM波等。可用于自动化控制、电源等领域。差异主要体现在一下方向：计数模式、捕获通道、死区等等。

通用定时器的定时体验，目前使用的LED闪烁是通过在while中延时实现的，这里我们通过定时器实现LED的闪烁功能。

初始化代码：

void port_Time_init(void)

{

Time3_init(48000, 10);//定时10ms

}

void Time3_init(u16 arr, u16 psc)

{

TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure={0};

NVIC_InitTypeDef NVIC_InitStruct={0};

RCC_APB1PeriphClockCmd( RCC_APB1Periph_TIM3, ENABLE );

TIM_TimeBaseInitStructure.TIM_Period = arr-1;

TIM_TimeBaseInitStructure.TIM_Prescaler = psc-1;

TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;

TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;

TIM_TimeBaseInit( TIM3, &TIM_TimeBaseInitStructure);

NVIC_InitStruct.NVIC_IRQChannel = TIM3_IRQn;

NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority = NVIC_PriorityGroup_0;

NVIC_InitStruct.NVIC_IRQChannelSubPriority = 3;

NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE;

NVIC_Init(&NVIC_InitStruct);

TIM_ITConfig(TIM3, TIM_IT_Update, ENABLE);

TIM_Cmd(TIM3, ENABLE);

}

中断代码：

void TIM3_IRQHandler(void) __attribute__((interrupt("WCH-Interrupt-fast")));

void TIM3_IRQHandler(void)

{

if(TIM_GetITStatus(TIM3, TIM_IT_Update) != RESET)

{

TIM_ClearITPendingBit(TIM3, TIM_IT_Update);

LED.Upcnt++;

if(LED.Upcnt%50 == 0)

{

LED.Upcnt = 0;

LED.UpFlag = 1;

}

}

}

定时器中断主要涉及的就是定时器的配置与中断配置，在官方的定时器使用模块中并没有有关定时器中断方面的例程，这方面也确实让我着实费了好长时间，一直无法进入中断，而且切换不同的定时器也无法进入,最后发现是出现在void TIM3_IRQHandler(void)attribute((interrupt("WCH-Interrupt-fast")));也就是除了在中断处理函数写相应代码，最重要的是上边这一句，为什么呢？而且一旦你前面中断开启，这里就必须有对应的开启，差一个程序就乱掉了，没有查到这一句是什么意思。

为了实现状态的切换，我们使用了五向按键的上键实现LED状态的切换：

初始化代码如下：

void port_EXTI_init(void)

{

GPIO_InitTypeDef GPIO_InitStructure = {0};

EXTI_InitTypeDef EXTI_InitStructure = {0};

NVIC_InitTypeDef NVIC_InitStructure = {0};

RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO | RCC_APB2Periph_GPIOA, ENABLE);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPD;

GPIO_Init(GPIOC, &GPIO_InitStructure);

/* GPIOC ----> EXTI_Line17 */

GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource0);

EXTI_InitStructure.EXTI_Line = EXTI_Line0;

EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;

EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising;

EXTI_InitStructure.EXTI_LineCmd = ENABLE;

EXTI_Init(&EXTI_InitStructure);

NVIC_InitStructure.NVIC_IRQChannel = EXTI7_0_IRQn;

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;

NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;

NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

NVIC_Init(&NVIC_InitStructure);

}

中断处理：

void EXTI7_0_IRQHandler(void) __attribute__((interrupt("WCH-Interrupt-fast")));

void EXTI7_0_IRQHandler(void)

{

if(EXTI_GetITStatus(EXTI_Line0)==SET)

{

LED.UpFlag = 1;

EXTI_ClearITPendingBit(EXTI_Line0); /* Clear Flag */

}

}

效果如下：

接下来就是体验定时器的PWM，这里我们使用的是定时器的互补PWM输出控制LED实现呼吸灯的效果，这也和我们后续对直流风机的控制是类似的，一个吹风一个吸风，正好是一个互补的效果。

初始化代码：

void TIM1_Dead_Time_Init(u16 arr, u16 psc, u16 ccp)

{

TIM_OCInitTypeDef TIM_OCInitStructure = {0};

TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure = {0};

TIM_BDTRInitTypeDef TIM_BDTRInitStructure = {0};

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_TIM1, ENABLE);

/* TIM1_CH1- GPIO_Pin_9 TIM1_CH2- GPIO_Pin_10*/

LED_GPIOPWM_init();

TIM_TimeBaseInitStructure.TIM_Period = (arr-1);

TIM_TimeBaseInitStructure.TIM_Prescaler = (psc-1);

TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;

TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;

TIM_TimeBaseInit(TIM1, &TIM_TimeBaseInitStructure);

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;

TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;

TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;

TIM_OCInitStructure.TIM_Pulse = ccp;

TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;

TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_Low;

TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;

TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCNIdleState_Reset;

TIM_OC1Init(TIM1, &TIM_OCInitStructure);

TIM_BDTRInitStructure.TIM_OSSIState = TIM_OSSIState_Disable;

TIM_BDTRInitStructure.TIM_OSSRState = TIM_OSSRState_Disable;

TIM_BDTRInitStructure.TIM_LOCKLevel = TIM_LOCKLevel_OFF;

TIM_BDTRInitStructure.TIM_DeadTime = 0xFF;

TIM_BDTRInitStructure.TIM_Break = TIM_Break_Disable;

TIM_BDTRInitStructure.TIM_BreakPolarity = TIM_BreakPolarity_High;

TIM_BDTRInitStructure.TIM_AutomaticOutput = TIM_AutomaticOutput_Enable;

TIM_BDTRConfig(TIM1, &TIM_BDTRInitStructure);

TIM_CtrlPWMOutputs(TIM1, ENABLE);

TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Disable);

TIM_ARRPreloadConfig(TIM1, ENABLE);

TIM_Cmd(TIM1, ENABLE);

}

并修改LED的控制函数：

void App_LED(void)

{

if(LED.Mode_Dis != LED.Mode_OidDis)

{

switch(LED.Mode_Dis)

{

case 0:

LED_GPIO_init();

TIM_Cmd(TIM1, DISABLE);

break;

case 1:

TIM1_Dead_Time_Init(100, 4800, 0);

LED.PWMcnt = 0;

break;

default:

break;

}

LED.Mode_OidDis = LED.Mode_Dis;

}

if(LED.UpFlag == 1)

{

if(LED.Mode_Dis == 0)

{

GPIO_WriteBit(GPIOB, GPIO_Pin_6, (i == 0) ? (i = Bit_SET) : (i = Bit_RESET));

GPIO_WriteBit(GPIOB, GPIO_Pin_9, (i != 0) ? (i = Bit_SET) : (i = Bit_RESET));

}

LED.UpFlag = 0;

}

}

中断处理函数：

void TIM3_IRQHandler(void)

{

if(TIM_GetITStatus(TIM3, TIM_IT_Update) != RESET)

{

TIM_ClearITPendingBit(TIM3, TIM_IT_Update);

if(LED.Mode_Dis == 0)

{

LED.Upcnt++;

if(LED.Upcnt%50 == 0)

{

LED.Upcnt = 0;

LED.UpFlag = 1;

}

}

else if(LED.Mode_Dis == 1)

{

LED.PWMcnt++;

if(LED.PWMcnt < 100)

{

TIM_SetCompare1(TIM1,100-LED.PWMcnt);

}

else if(LED.PWMcnt >= 100 && LED.PWMcnt < 200)

{

TIM_SetCompare1(TIM1,LED.PWMcnt-100);

}

else if(LED.PWMcnt >= 200)

{

LED.PWMcnt = 0;

}

}

}

}

void EXTI7_0_IRQHandler(void)

{

if(EXTI_GetITStatus(EXTI_Line0)==SET)

{

LED.Mode_Dis++;

LED.Mode_Dis = LED.Mode_Dis%2;

EXTI_ClearITPendingBit(EXTI_Line0); /* Clear Flag */

}

}

效果如下：

通过本次章节的使用，我们对外部中断、定时器中断、定时器PWM输出有了基本的了解，里边有一些坑也采到了，通过这些功能的组合展现了一个LED的多样控制。