STM32一定时器产生不同频率的PWM
(1)使能定时器时钟:RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
(2)定义相应的GPIO:
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2|GPIO_Pin_3|GPIO_Pin_4|GPIO_Pin_5|GPIO_Pin_6;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU; //下拉接地,检测输入的高电平
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //50M时钟速度
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //50M时钟速度
GPIO_Init(GPIOA, &GPIO_InitStructure);
(3)如果是产生PWM(频率不变,占空比可变),记得打开PWM控制,在TIM_Configuration()中。
TIM_Cmd(TIM3,ENABLE);
TIM_CtrlPWMOutputs(TIM1,ENABLE);
利用定时器产生不同频率的PWM
(一) 设置的原理
(二)关键设置
在定时器设置中:TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Disable);
在中断函数中: if (TIM_GetITStatus(TIM3, TIM_IT_CC2) != RESET)
}
一个定时器四个通道,分别产生不同频率(这个例子网上也有)
vu16 CCR1_Val = 32768;
vu16 CCR2_Val = 16384;
vu16 CCR3_Val = 8192;
vu16 CCR4_Val = 4096;
void TIM_Configuration(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
TIM_TimeBaseStructure.TIM_Period = 65535;
TIM_TimeBaseStructure.TIM_Prescaler = 2;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //正向通道有效
TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Disable;//反向通道无效
TIM_OCInitStructure.TIM_Pulse = CCR1_Val;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High;
TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset;
TIM_OC1Init(TIM2,&TIM_OCInitStructure);
TIM_OC1PreloadConfig(TIM2, TIM_OCPreload_Disable);
TIM_OCInitStructure.TIM_Pulse = CCR2_Val;
TIM_OC2Init(TIM2,&TIM_OCInitStructure);
TIM_OC2PreloadConfig(TIM2, TIM_OCPreload_Disable);
TIM_OCInitStructure.TIM_Pulse = CCR3_Val;
TIM_OC3Init(TIM2,&TIM_OCInitStructure);
TIM_OC3PreloadConfig(TIM2, TIM_OCPreload_Disable);
TIM_OCInitStructure.TIM_Pulse = CCR4_Val;
TIM_OC4Init(TIM2,&TIM_OCInitStructure);
TIM_OC4PreloadConfig(TIM2, TIM_OCPreload_Disable);
TIM_Cmd(TIM2,ENABLE);
//TIM_CtrlPWMOutputs(TIM2,ENABLE);
TIM_ITConfig(TIM2, TIM_IT_CC1 | TIM_IT_CC2 | TIM_IT_CC3 | TIM_IT_CC4, ENABLE);
}
void GPIO_Configuration(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOD, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2|GPIO_Pin_3|GPIO_Pin_4|GPIO_Pin_5|GPIO_Pin_6|GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_OD; //开漏输出
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //50M时钟速度
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0|GPIO_Pin_1;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_OD; //开漏输出
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //50M时钟速度
GPIO_Init(GPIOB, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0|GPIO_Pin_1;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
GPIO_Init(GPIOC, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
GPIO_Init(GPIOB, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
}
void NVIC_Configuration(void)
{
NVIC_InitTypeDef NVIC_InitStructure;
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);
NVIC_InitStructure.NVIC_IRQChannel=TIM2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPrio
NVIC_InitStructure.NVIC_IRQChannelSubPriority=1;
NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
u16 capture = 0;
extern vu16 CCR1_Val;
extern vu16 CCR2_Val;
extern vu16 CCR3_Val;
extern vu16 CCR4_Val;
void TIM2_IRQHandler(void)
{
if (TIM_GetITStatus(TIM2, TIM_IT_CC1) != RESET)
{
capture = TIM_GetCapture1(TIM2);
TIM_SetCompare1(TIM2, capture + CCR1_Val );
}
if (TIM_GetITStatus(TIM2, TIM_IT_CC2) != RESET)
{
capture = TIM_GetCapture2(TIM2);
}
if (TIM_GetITStatus(TIM2, TIM_IT_CC3) != RESET)
{
capture = TIM_GetCapture3(TIM2);
}
if (TIM_GetITStatus(TIM2, TIM_IT_CC4) != RESET)
{
capture = TIM_GetCapture4(TIM2);
}
}
一个定时器一个通道,产生不同频率
其它的设置都一样,就是在主函数中修改一个参数,然后在定时器中断中,根据这个参数,改变频率。
#include "stm32libstm32f10x.h"
#include "hal.h"
volatile u16 Key_Value=1000;
int main(void)
{
ChipHalInit();
ChipOutHalInit();
while(1)
{
}
}
extern volatile u16 Key_Value;
u16 capture=0;
void TIM3_IRQHandler(void)
{
if (TIM_GetITStatus(TIM3, TIM_IT_CC2) != RESET)
{
capture = TIM_GetCapture2(TIM3);
}
}
void TIM3_Configuration(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
TIM_TimeBaseStructure.TIM_Prescaler = 5;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseStructure.TIM_Period = 65535;
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseStructure.TIM_RepetitionCounter = 0x0;
TIM_TimeBaseInit(TIM3,&TIM_TimeBaseStructure);
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //正向通道有效
TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Disable;//反向通道无效
TIM_OCInitStructure.TIM_Pulse = Key_Value;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High;
TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset;
TIM_OC2Init(TIM3,&TIM_OCInitStructure);
TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Disable);
TIM_Cmd(TIM3,ENABLE);
//TIM_CtrlPWMOutputs(TIM1,ENABLE);
TIM_ITConfig(TIM3, TIM_IT_CC2 , ENABLE);
}
注意:在计算PWM频率的时候,TIMx的时钟都是72Mhz,分频后,因为翻转两次才能形成一个PWM波,因为,PWM的频率是捕获改变频率的1/2。
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