TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
表麵意思是輸出控製極性為高，但是意思是定時器輸入0，不反相，輸出0；
輸出控製極性為低，定時器輸入0，反相輸出1；
CC1E控製開關。
#define TIM_OCPolarity_High ((uint16_t)0x0000)
#define TIM_OCPolarity_Low ((uint16_t)0x0002)
定時器通道寫法： TIM_OC2 意思是定時器channel 2 ，TIM_OC1意思是定時器通道1.
//小波Linux
pwm占空比：
TIM_SetCompare1(TIM2,led1pwmval);
TIM_SetCompare2(TIM3,led0pwmval);
TIMX為哪個定時器，ledxpwmval為占空比的值；
TIM2_PWM_Init(899,0); //不分頻 72000/900=8Khz
arr 自動重裝載計數器初值 900 =899+1；
占空比例如 占 50% = 450 / 900
ledxpwmval = 450;
定時器初始化，裏麵有個重映射
void TIM2_PWM_Init(u16 arr,u16 psc) {
GPIO_InitTypeDef GPIO_InitStructure; TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; TIM_OCInitTypeDef TIM_OCInitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE); //使能定時器3時鍾 RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE); //使能GPIO外設和AFIO複用功能模塊時鍾
//設置該引腳為複用輸出功能,輸出TIM2 CH1的PWM脈衝波形
PA0 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0; //
TIM_CH1 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //複用推挽輸出
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);//初始化GPIO //初始化
TIM2 TIM_TimeBaseStructure.TIM_Period = arr; //設置在下一個更新事件裝入活動的自動重裝載寄存器周期的值 TIM_TimeBaseStructure.TIM_Prescaler =psc; //設置用來作為TIMx時鍾頻率除數的預分頻值 TIM_TimeBaseStructure.TIM_ClockDivision = 0; //設置時鍾分割:
TDTS = Tck_tim
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM向上計數模式
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure); //根據TIM_TimeBaseInitStruct中指定的參數初始化TIMx的時間基數單位 //初始化TIM2 Channel 1 PWM模式
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //選擇定時器模式:TIM脈衝寬度調製模式2 TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //比較輸出使能 TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //輸出極性:TIM輸出比較極性高
TIM_OC1Init(TIM2, &TIM_OCInitStructure); //根據T指定的參數初始化外設TIM2 OC1
TIM_OC1PreloadConfig(TIM2, TIM_OCPreload_Enable); //使能TIM2在CCR1上的預裝載寄存器
TIM_Cmd(TIM2, ENABLE); //使能TIM2
}
//TIM3 PWM部分初始化 //PWM輸出初始化 //arr：自動重裝值 //psc：時鍾預分頻數
void TIM3_PWM_Init(u16 arr,u16 psc) { GPIO_InitTypeDef GPIO_InitStructure; TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; TIM_OCInitTypeDef TIM_OCInitStructure; RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); //使能定時器3時鍾 RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE); //使能GPIO外設和AFIO複用功能模塊時鍾
GPIO_PinRemapConfig(GPIO_PartialRemap_TIM3, ENABLE); //Timer3部分重映射
TIM3_CH2->PB5 //設置該引腳為複用輸出功能,輸出TIM3 CH2的PWM脈衝波形 GPIOB.5 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5; //
TIM_CH2 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //複用推挽輸出
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &GPIO_InitStructure);//初始化GPIO //初始化TIM3
TIM_TimeBaseStructure.TIM_Period = arr; //設置在下一個更新事件裝入活動的自動重裝載寄存器周期的值 TIM_TimeBaseStructure.TIM_Prescaler =psc; //設置用來作為TIMx時鍾頻率除數的預分頻值 TIM_TimeBaseStructure.TIM_ClockDivision = 0; //設置時鍾分割:TDTS = Tck_tim TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM向上計數模式
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); //根據TIM_TimeBaseInitStruct中指定的參數初始化TIMx的時間基數單位 //初始化TIM3 Channel2 PWM模式
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //選擇定時器模式:TIM脈衝寬度調製模式2 TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //比較輸出使能 TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //輸出極性:TIM輸出比較極性高
TIM_OC2Init(TIM3, &TIM_OCInitStructure); //根據T指定的參數初始化外設TIM3 OC2
TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable); //使能TIM3在CCR2上的預裝載寄存器
TIM_Cmd(TIM3, ENABLE); //使能TIM3
}
