STM32F1 PWM波 PB4沒輸出?
很多人遇到這種問題,但是應該注意的是PB4在微控制器復位後,它是作為JTAG引腳來使用的,也就是說,要使用PB4你需要自己將其配置成普通GPIO,GPIO_PinRemapConfig(GPIO_Remap_SWJ_JTAGDisable,ENABLE);
配置成普通GPIO後,需要進行部分重對映,GPIO_PinRemapConfig(GPIO_PartialRemap_TIM3 , ENABLE);
兩步都完成後即可得到正常的PWM波輸出,下面附上完整PWM配置程式
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; TIM_OCInitTypeDef TIM_OCInitStructure; GPIO_InitTypeDef GPIO_InitStructure; RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE); GPIO_PinRemapConfig(GPIO_Remap_SWJ_JTAGDisable,ENABLE); GPIO_PinRemapConfig(GPIO_PartialRemap_TIM3 , ENABLE); GPIO_InitStructure.GPIO_Pin =GPIO_Pin_4|GPIO_Pin_5; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; GPIO_Init(GPIOB, &GPIO_InitStructure);
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_PWM1; TIM_OCInitStructure.TIM_Pulse = 333; TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; TIM_OC1Init(TIM3, &TIM_OCInitStructure); TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Enable); TIM_OC2Init(TIM3, &TIM_OCInitStructure); TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable); TIM_ARRPreloadConfig(TIM3, ENABLE); TIM_Cmd(TIM3, ENABLE);