欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页

STM32输出 PWM频率 占空比 连续可调~~

程序员文章站 2022-06-08 20:47:56
...

来一波不同凡响的PWM

话不多说 直接上代码 我的平台是 stm32F407VGT6 PA0 输出 使用定时器TIM2


//编程输出可调的硬件PWM,频率范围1Hz - 1MHz,占空比0 - 100 %

uint32_t TIM2_PWM_FQ = 50;             /* TIM2_CH1_PWM输出 频率设置值,1-1000000 */
uint32_t TIM2_PWM_FQ_Old  = 0;
uint16_t TIM2_PWM_Pulse = 50;          /* TIM2_CH1_PWM输出 占空比设置值,0-100 */
uint16_t TIM2_PWM_Pulse_Old = 0;

uint32_t SystemCoreClock = 168000000;

/*
* 函数功能: 定时器4配置为硬件PWM模式(不开启TIM2的定时及DMA传输中断)
* TIM2_PWM_FQ:     TIM2_CH1_PWM 频率    1Hz至1000000Hz
* TIM2_PWM_Pulse:  TIM2_CH1_PWM 占空比  0-100%
*/
void StdPeriph_TIM2_PWM_Config(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
    TIM_OCInitTypeDef  TIM_OCInitStructure;

    uint32_t temp32;
    uint32_t uhTimerfrequency;
    uint16_t uhTimerPeriod;
    uint16_t uhTimerPulse;

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);  
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
    // GPIOB Configuration
    GPIO_InitStruct.GPIO_Pin = GPIO_Pin_0;
    GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;
    GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_DOWN;
    GPIO_InitStruct.GPIO_Speed = GPIO_Speed_100MHz;
    GPIO_Init(GPIOA, &GPIO_InitStruct);

    GPIO_PinAFConfig(GPIOA, GPIO_PinSource0, GPIO_AF_TIM2);

    uhTimerfrequency = 200000; /* 初始化 200KHz */
    temp32 = ((SystemCoreClock / 2) / uhTimerfrequency);
    if (temp32 > 65535) temp32 = 65535;
    uhTimerPeriod = (uint16_t) temp32;
    uhTimerPulse  = uhTimerPeriod * 50 / 100; /* 占空比50% */

    // Time base configuration
    TIM_TimeBaseStructure.TIM_Period = uhTimerPeriod - 1; /* 0x0000 and 0xFFFF */
    TIM_TimeBaseStructure.TIM_Prescaler = 0; /* 0x0000 and 0xFFFF */
    TIM_TimeBaseStructure.TIM_ClockDivision = 0;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

    // PWM1 Mode configuration: Channel1
    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_Pulse = uhTimerPulse;
    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;

    TIM_OC1Init(TIM2, &TIM_OCInitStructure);
    TIM_OC1PreloadConfig(TIM2, TIM_OCPreload_Enable);
    TIM_ARRPreloadConfig(TIM2, ENABLE);
    TIM_GenerateEvent(TIM2, TIM_EventSource_Update);

    TIM_Cmd(TIM2, ENABLE);
}

/*
* 函数功能: 刷新TIM2_CH1_PWM输出的频率和占空比
* 修改TIM2_PWM_FQ的值,调节PWM频率(1Hz至1MHz)
* 修改TIM2_PWM_Pulse的值,调节PWM的占空比(0-100)
*/

void StdPeriph_TIM2_PWM_Update(void)
{
    uint32_t temp32;
    uint32_t uhTimerfrequency;
    uint16_t uhTimerPeriod;
    uint16_t uhTimerPrescaler;
    uint16_t uhTimerPulse;

    if ((TIM2_PWM_FQ_Old != TIM2_PWM_FQ) || (TIM2_PWM_Pulse_Old != TIM2_PWM_Pulse)) {
        TIM2_PWM_FQ_Old = TIM2_PWM_FQ;
        TIM2_PWM_Pulse_Old = TIM2_PWM_Pulse;
        if (TIM2_PWM_FQ >= 4000) {
            uhTimerfrequency = TIM2_PWM_FQ;  /* 定时器计时频率和PWM频率相等 */
            uhTimerPrescaler = 1;    /* 实际频率TIM2_PWM_FQ较大时,TIM2设置分频为1(不分频)   */
        } else {
            uhTimerfrequency = 4000; /* 实际频率TIM2_PWM_FQ较小时,和4000Hz的频率比较,看相差几倍 */
            uhTimerPrescaler = 4000 / TIM2_PWM_FQ;  /* 实际频率和4000相差的倍数作为TIM2的分频设置值 */
            uhTimerfrequency = uhTimerPrescaler * TIM2_PWM_FQ; /* TIM2分频后,计时周期变长,需要将uhTimerfrequency倍频  */
        }

        /* TIM2的周期要通过倍频uhTimerfrequency来计算,uhTimerPeriod = 84MHz / uhTimerfrequency */
        temp32 = ((SystemCoreClock / 2) / uhTimerfrequency);
        if (temp32 > 65535) temp32 = 65535;
        uhTimerPeriod = (uint16_t) temp32;

        if (TIM2_PWM_Pulse > 100) TIM2_PWM_Pulse = 100;
        uhTimerPulse = uhTimerPeriod * TIM2_PWM_Pulse / 100;

        TIM2->ARR  = uhTimerPeriod - 1;
        TIM2->PSC  = uhTimerPrescaler - 1;
        TIM2->CCR1 = uhTimerPulse;
        TIM2->EGR  = TIM_PSCReloadMode_Update;
    }
}

继续使用这个不同凡响的PWM吧

STM32输出 PWM频率 占空比 连续可调~~

相关标签: PWM 可调