stm32对定时器2CH3CH4输出的pwn波记高电平次数代码
时间: 2024-01-05 09:02:15 浏览: 34
以下是使用STM32的定时器2(TIM2)的CH3和CH4输出PWM波的代码示例。该代码将PWM占空比设置为50%,并将高电平持续时间设置为1秒钟。
```
#include "stm32f4xx.h"
void TIM2_PWM_Init(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
TIM_TimeBaseStructure.TIM_Period = 999; // PWM频率 = (84000000 / (Period + 1)) Hz
TIM_TimeBaseStructure.TIM_Prescaler = 83; // 时钟预分频 = (84MHz / (Prescaler + 1)) Hz
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = 499; // 占空比 = (Pulse + 1) / (Period + 1)
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OC3Init(TIM2, &TIM_OCInitStructure); // CH3 PWM波
TIM_OC4Init(TIM2, &TIM_OCInitStructure); // CH4 PWM波
TIM_Cmd(TIM2, ENABLE);
}
int main(void)
{
TIM2_PWM_Init();
while(1)
{
TIM_SetCompare3(TIM2, 499); // CH3高电平持续时间 = (Pulse + 1) / PWM频率 = 0.006s = 6ms
TIM_SetCompare4(TIM2, 499); // CH4高电平持续时间 = (Pulse + 1) / PWM频率 = 0.006s = 6ms
Delay(1000); // 延时1秒钟
}
}
```
在此示例中,使用TIM2定时器,将频率设置为84MHz,并使用时钟预分频器将其分为1MHz。然后,将计数器模式设置为向上计数,并将周期设置为999,以实现1kHz的PWM频率。使用TIM_OC3Init和TIM_OC4Init函数初始化CH3和CH4 PWM输出通道,并将占空比设置为50%(即PWM脉冲持续时间为500)。在主循环中,将CH3和CH4的高电平持续时间设置为1秒钟,并使用Delay函数延迟1秒钟。请注意,此代码仅为示例,您需要根据实际需求进行修改。