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由于前面买的核心板，供电老有问题，使得我现在的项目又改用了以前用的F103ZET6微控制器！
1、实验目的
1）产生脉宽任意可调的单脉冲（在允许的范围内）
2、硬件：通用定时器3、通用定时器4
3、单脉冲模式介绍
单脉冲模式允许计数器响应一个激励，并在一个程序可控的延时之后，产生一个脉宽可程序控制的脉冲。
可以通过从模式控制器启动计数器，在输出比较模式或者PWM模式下产生波形。设置TIMx_CR1 寄存器中的OPM 位将选择单脉冲模式，这样可以让计数器自动的产生下一个更新
事情UEV时停止。
仅当比较值与计数器的初始值不同时，才能产生一个脉冲。启动之前（当定时器正在等待触发），必须配置如下：
向上计数方式：CNT (计数器寄存器) < CCRx （比较寄存器）< ARR(自动装载寄存器)
向下计数方式：CNT > CCRx。
/**
******************************************************************************
* @file timonepulse.c
* @author Cawen
* @version V1.0
* @date 2015-12-22
******************************************************************************
*/
/* Includes ------------------------------------------------------------------*/
#include"timonepulse.h"
/* Private variables ---------------------------------------------------------*/
uint16_t PrescalerValue = 0;
/*
* Function Name : GPIO_Configuration
* Description : Configure the GPIOD Pins.
* Input : None
* Output : None
* Return : None
* Attention : None
*/
void GPIO_Configuration(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
/* TIM4_CH1 pin (PB.06) configuration */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &GPIO_InitStructure);
/* TIM4_CH2 pin (PB.07) configuration */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_Init(GPIOB, &GPIO_InitStructure);
}
/*
* Function Name : TIM4_Configuration
* Description : TIM4 configuration: One Pulse mode
The external signal is connected to TIM4_CH2 pin (PB.07),
The Rising edge is used as active edge,
The One Pulse signal is output on TIM4_CH1 pin (PB.06)
The TIM_Pulse defines the delay value
The (TIM_Period - TIM_Pulse) defines the One Pulse value.
TIM2CLK = SystemCoreClock, we want to get TIM2 counter clock at 24 MHz:
- Prescaler = (TIM2CLK / TIM2 counter clock) - 1
The Autoreload value is 65535 (TIM4->ARR), so the maximum frequency value
to trigger the TIM4 input is 24000000/65535 = 300 Hz.
The TIM_Pulse defines the delay value, the delay value is fixed
to 682.6 us:
delay = CCR1/TIM4 counter clock = 682.6 us.
The (TIM_Period - TIM_Pulse) defines the One Pulse value,
the pulse value is fixed to 2.048 ms:
One Pulse value = (TIM_Period - TIM_Pulse) / TIM4 counter clock = 2.048 ms.
* Input : None
* Output : None
* Return : None
* Attention : None
*/
void TIM4_Configuration(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_ICInitTypeDef TIM_ICInitStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
/* TIM4 and GPIOB clock enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
/* Compute the prescaler value */
PrescalerValue = (uint16_t) (72000000 / 10000) - 1;
/* Time base configuration */
TIM_TimeBaseStructure.TIM_Period = 5999;
TIM_TimeBaseStructure.TIM_Prescaler = PrescalerValue;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure);
/* TIM4 PWM2 Mode configuration: Channel1 */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = 2000;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OC1Init(TIM4, &TIM_OCInitStructure);
/* TIM4 configuration in Input Capture Mode */
TIM_ICStructInit(&TIM_ICInitStructure);//恢复缺省值
TIM_ICInitStructure.TIM_Channel = TIM_Channel_2;//选择输入端IC2映射到TI2上
TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;//上升沿捕获
TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;//映射到TI2上
TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;//配置输入分频，不分频
TIM_ICInitStructure.TIM_ICFilter = 0;//配置输入滤波，不滤波
TIM_ICInit(TIM4, &TIM_ICInitStructure);
/* 单脉冲模式选择 */
TIM_SelectOnePulseMode(TIM4, TIM_OPMode_Single);//生成单一的脉冲：计数器在下一个更新事件停止
/* 选择 TIM 输入触发源 */
TIM_SelectInputTrigger(TIM4, TIM_TS_TI2FP2);//TIM 经滤波定时器输入2
/* 选择 TIM 从模式 */
TIM_SelectSlaveMode(TIM4, TIM_SlaveMode_Trigger); //计数器在触发的上升沿开始
}
/*
* Function Name : TIM3_PWM_Init(u16 arr,u16 psc)
* Description : TIM3 PWM部分初始化
PWM输出初始化
arr：自动重装值
psc：时钟预分频数
* Input : None
* Output : None
* Return : None
* Attention : None
*/
void TIM3_PWM_Init(u16 arr,u16 psc)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); //使能定时器3时钟
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE); //使能GPIO外设时钟
TIM_ITConfig(TIM3,TIM_IT_Update,ENABLE ); //使能指定的TIM3中断,允许更新中断
NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn; //TIM3中断
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; //先占优先级0级
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3; //从优先级3级
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道被使能
NVIC_Init(&NVIC_InitStructure); //根据NVIC_InitStruct中指定的参数初始化外设NVIC寄存器
//设置该引脚为复用输出功能,输出TIM3 CH2的PWM脉冲波形 GPIOA7
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7; //TIM_CH2
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //复用推挽输出
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);//初始化GPIO
//初始化TIM3
TIM_TimeBaseStructure.TIM_Period = arr; //设置在下一个更新事件装入活动的自动重装载寄存器周期的值
TIM_TimeBaseStructure.TIM_Prescaler =psc; //设置用来作为TIMx时钟频率除数的预分频值
TIM_TimeBaseStructure.TIM_ClockDivision = 0; //设置时钟分割:TDTS = Tck_tim
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM向上计数模式
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); //根据TIM_TimeBaseInitStruct中指定的参数初始化TIMx的时间基数单位
//初始化TIM3 Channel2 PWM模式
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //选择定时器模式:TIM脉冲宽度调制模式2
TIM_OCInitStructure.TIM_Pulse = 5000;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //比较输出使能
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //输出极性:TIM输出比较极性高
TIM_OC2Init(TIM3, &TIM_OCInitStructure); //根据T指定的参数初始化外设TIM3 OC2
TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable); //使能TIM3在CCR2上的预装载寄存器
TIM_Cmd(TIM3, ENABLE); //使能TIM3
}
//定时器3中断服务程序
void TIM3_IRQHandler(void) //TIM3中断
{
if (TIM_GetITStatus(TIM3, TIM_IT_Update) != RESET) //检查指定的TIM中断发生与否:TIM 中断源
{
TIM_ClearITPendingBit(TIM3, TIM_IT_Update); //清除TIMx的中断待处理位:TIM 中断源
TIM_Cmd(TIM3, DISABLE); //失能TIM3
}
}
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