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- #include "bsp_pwm_output.h"
- /**
- * @brief 配置TIM3复用输出PWM时用到的I/O
- * @param 无
- * @retval 无
- */
- static void TIMx_GPIO_Config(void)
- {
- GPIO_InitTypeDef GPIO_InitStructure;
-
- RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB| RCC_APB2Periph_AFIO,ENABLE);
- GPIO_PinRemapConfig(GPIO_Remap_SWJ_NoJTRST, ENABLE); //PB4
- GPIO_PinRemapConfig(GPIO_PartialRemap_TIM3, ENABLE);
- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;
- GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
- GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
- GPIO_Init(GPIOB, &GPIO_InitStructure);
- // /*GPIOB Configuration: TIM3 channel 2 as alternate function push-pull */
- // GPIO_InitStructure.GPIO_Pin = macTIM_CH2_PIN;
- // GPIO_Init(macTIM_CH2_PORT, &GPIO_InitStructure);
- }
- /**
- * @brief 配置TIM3输出的PWM信号的模式，如周期、极性、占空比
- * @param 无
- * @retval 无
- */
- /*
- * TIMxCLK/CK_PSC --> TIMxCNT --> TIMx_ARR --> TIMxCNT 重新计数
- * TIMx_CCR(电平发生变化)
- * 信号周期=(TIMx_ARR +1 ) * 时钟周期
- * 占空比=TIMx_CCR/(TIMx_ARR +1)
- */
- static void TIMx_Mode_Config(void)
- {
- TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
- TIM_OCInitTypeDef TIM_OCInitStructure;
- /* PWM信号电平跳变值 */
- u16 CCR1_Val = 500;
- u16 CCR2_Val = 0;
- // u16 CCR3_Val = 250;
- // u16 CCR4_Val = 125;
- /* -----------------------------------------------------------------------
- macTIMx Channel1 duty cycle = (macTIMx_CCR1/ macTIMx_ARR+1)* 100% = 50%
- macTIMx Channel2 duty cycle = (macTIMx_CCR2/ macTIMx_ARR+1)* 100% = 37.5%
- macTIMx Channel3 duty cycle = (macTIMx_CCR3/ macTIMx_ARR+1)* 100% = 25%
- macTIMx Channel4 duty cycle = (macTIMx_CCR4/ macTIMx_ARR+1)* 100% = 12.5%
- ----------------------------------------------------------------------- */
- /* Time base configuration */
- TIM_TimeBaseStructure.TIM_Period = 999; //当定时器从0计数到999，即为1000次，为一个定时周期
- TIM_TimeBaseStructure.TIM_Prescaler = 0; //设置预分频：不预分频，即为72MHz
- TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1 ; //设置时钟分频系数：不分频(这里用不到)
- TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //向上计数模式
- TIM_TimeBaseInit(macTIMx, &TIM_TimeBaseStructure);
- /* PWM1 Mode configuration: Channel1 */
- TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //配置为PWM模式1
- TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
- TIM_OCInitStructure.TIM_Pulse = CCR1_Val; //设置跳变值，当计数器计数到这个值时，电平发生跳变
- TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //当定时器计数值小于CCR1_Val时为高电平
- TIM_OC1Init(macTIMx, &TIM_OCInitStructure); //使能通道1
- TIM_OC1PreloadConfig(macTIMx, TIM_OCPreload_Enable);
- // /* PWM1 Mode configuration: Channel2 */
- TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
- TIM_OCInitStructure.TIM_Pulse = CCR2_Val; //设置通道2的电平跳变值，输出另外一个占空比的PWM
- TIM_OC2Init(macTIMx, &TIM_OCInitStructure); //使能通道2
- TIM_OC2PreloadConfig(macTIMx, TIM_OCPreload_Enable);
- TIM_ARRPreloadConfig(macTIMx, ENABLE); // 使能TIM3重载寄存器ARR
- /* TIM3 enable counter */
- TIM_Cmd(macTIMx, ENABLE); //使能定时器3
- }
- /**
- * @brief TIM3 输出PWM信号初始化，只要调用这个函数
- * TIM3的四个通道就会有PWM信号输出
- * @param 无
- * @retval 无
- */
- void TIMx_PWM_Init(void)
- {
- TIMx_GPIO_Config();
- TIMx_Mode_Config();
- }
- /*********************************************END OF FILE**********************/
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