参考文章:STM32之PWM波形输出配置总结
代码:
- // target = sys/(arr+1)/(psc+1)
- void TIM3_PWM_Init(u16 arr,u16 psc)
- {
- GPIO_InitTypeDef GPIO_InitStructure;
- TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
- TIM_OCInitTypeDef TIM_OCInitStructure;
- RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE);
- GPIO_PinRemapConfig(GPIO_PartialRemap_TIM3, ENABLE);
- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;
- GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
- GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
- GPIO_Init(GPIOB, &GPIO_InitStructure);
- RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
- TIM_TimeBaseStructure.TIM_Period = arr;
- TIM_TimeBaseStructure.TIM_Prescaler = psc;
- TIM_TimeBaseStructure.TIM_ClockDivision = 0;
- TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
- TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);
- TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
- TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
- TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
- TIM_OC2Init(TIM3, &TIM_OCInitStructure);
- TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable);
- TIM_Cmd(TIM3, ENABLE);
- }
生成频率计算公式为:
主频 /(arr+1)/(psc+1)
调用时:
TIM3_PWM_Init(arr, psc);
TIM_SetCompare2(TIM3, ss);
占空比 = ss/arr+1