编写一个stm32输出pwm函数
时间: 2023-11-13 19:04:26 浏览: 40
以下是一个基本的STM32输出PWM的函数:
```c
void PWM_Output_Init(TIM_TypeDef* TIMx, uint32_t channel, uint32_t freq, uint32_t duty_cycle) {
// Enable the timer clock
if (TIMx == TIM1) {
RCC->APB2ENR |= RCC_APB2ENR_TIM1EN;
} else if (TIMx == TIM2) {
RCC->APB1ENR |= RCC_APB1ENR_TIM2EN;
} else if (TIMx == TIM3) {
RCC->APB1ENR |= RCC_APB1ENR_TIM3EN;
} else if (TIMx == TIM4) {
RCC->APB1ENR |= RCC_APB1ENR_TIM4EN;
} else if (TIMx == TIM5) {
RCC->APB1ENR |= RCC_APB1ENR_TIM5EN;
} else if (TIMx == TIM6) {
RCC->APB1ENR |= RCC_APB1ENR_TIM6EN;
} else if (TIMx == TIM7) {
RCC->APB1ENR |= RCC_APB1ENR_TIM7EN;
} else if (TIMx == TIM8) {
RCC->APB2ENR |= RCC_APB2ENR_TIM8EN;
} else if (TIMx == TIM9) {
RCC->APB2ENR |= RCC_APB2ENR_TIM9EN;
} else if (TIMx == TIM10) {
RCC->APB2ENR |= RCC_APB2ENR_TIM10EN;
} else if (TIMx == TIM11) {
RCC->APB2ENR |= RCC_APB2ENR_TIM11EN;
} else if (TIMx == TIM12) {
RCC->APB1ENR |= RCC_APB1ENR_TIM12EN;
} else if (TIMx == TIM13) {
RCC->APB1ENR |= RCC_APB1ENR_TIM13EN;
} else if (TIMx == TIM14) {
RCC->APB1ENR |= RCC_APB1ENR_TIM14EN;
} else {
return;
}
// Configure the timer
TIMx->CR1 = 0; // Disable the timer
TIMx->PSC = ((SystemCoreClock / 2) / freq) - 1; // Set the prescaler
TIMx->ARR = 100; // Set the auto-reload value
TIMx->CCR[channel - 1] = duty_cycle; // Set the duty cycle
TIMx->CCMR1 |= TIM_CCMR1_OC1M_2 | TIM_CCMR1_OC1M_1 | TIM_CCMR1_OC1PE; // PWM mode 1, preload enable
TIMx->CCER |= TIM_CCER_CC1E; // Enable the output
// Start the timer
TIMx->EGR |= TIM_EGR_UG; // Generate an update event to reload the prescaler and ARR
TIMx->CR1 |= TIM_CR1_CEN; // Enable the timer
}
```
该函数使用了STM32标准库中的一些寄存器来配置定时器和输出PWM信号。函数参数包括定时器的类型(TIM1-TIM14),PWM通道(1-4),PWM频率和占空比。占空比为0-100之间的值,表示高电平所占的比例。
使用该函数时,只需要调用`PWM_Output_Init()`函数并传入所需参数即可。例如,如果要在PB8引脚上输出500Hz的PWM信号,并将占空比设置为50%,则可以使用以下代码:
```c
PWM_Output_Init(TIM4, 3, 500, 50);
```
其中,定时器类型为TIM4,PWM通道为3(对应于PB8引脚),PWM频率为500Hz,占空比为50%。