写一个基于stm32f407ZGTE6的,在PB11输出变化的pwm的代码
时间: 2024-06-10 20:05:56 浏览: 6
好的,我理解了您的要求。以下是基于stm32f407ZGTE6的,在PB11输出变化的pwm的代码示例:
```
#include "stm32f4xx.h"
int main(void)
{
GPIO_InitTypeDef GPIO_InitStruct;
TIM_TimeBaseInitTypeDef TIM_InitStruct;
TIM_OCInitTypeDef TIM_OCInitStruct;
// Enable the clock for GPIOB
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);
// Enable the clock for TIM4
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);
// Set PB11 as alternate function mode
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_11;
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_Init(GPIOB, &GPIO_InitStruct);
// Connect TIM4 pins to alternate function
GPIO_PinAFConfig(GPIOB, GPIO_PinSource11, GPIO_AF_TIM4);
// Initialize the timer
TIM_InitStruct.TIM_Prescaler = 199; // 200MHz / (199 + 1) = 1MHz
TIM_InitStruct.TIM_CounterMode = TIM_CounterMode_Up;
TIM_InitStruct.TIM_Period = 9999; // 1MHz / (9999 + 1) = 100Hz
TIM_InitStruct.TIM_ClockDivision = 0;
TIM_TimeBaseInit(TIM4, &TIM_InitStruct);
// Initialize the PWM channel
TIM_OCInitStruct.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStruct.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStruct.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OCInitStruct.TIM_Pulse = 5000; // duty cycle = (5000 / 10000) = 50%
TIM_OC2Init(TIM4, &TIM_OCInitStruct);
// Start the timer
TIM_Cmd(TIM4, ENABLE);
while(1)
{
// Change the duty cycle
for(int i = 0; i < 10000; i++)
{
TIM_SetCompare2(TIM4, i);
for(int j = 0; j < 500; j++); // delay
}
}
}
```
这段代码使用了定时器TIM4的PWM输出功能,将PB11设置为TIM4_CH2的复用功能,并在程序中实现了一个50%占空比的PWM信号,并通过一个循环改变了占空比,实现PWM波形的变化。希望能对您有所帮助。