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。
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