用STM32F030C8T6 写一个PID 控制电机的程序,通过PB0引脚检测脉冲数量,根据脉冲数来改变PA8的PWM输出占空比

由于PID控制需要实时监测电机的运行情况，因此需要一个定时器来定时检测脉冲数量。本例使用定时器TIM2来实现。

首先需要初始化GPIO，设置PB0为输入，PA8为输出。

void GPIO_Init(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;

    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB | RCC_AHBPeriph_GPIOA, ENABLE);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
    GPIO_Init(GPIOB, &GPIO_InitStructure);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    GPIO_PinAFConfig(GPIOA, GPIO_PinSource8, GPIO_AF_2);
}

然后需要初始化定时器TIM2，设置定时器时钟为72MHz，定时器周期为1ms。

void TIM2_Init(void)
{
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

    TIM_TimeBaseStructure.TIM_Prescaler = 71;
    TIM_TimeBaseStructure.TIM_Period = 999;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
    TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
    TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

    TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);

    TIM_Cmd(TIM2, ENABLE);
}

接下来需要编写中断服务函数，定时器TIM2每1ms中断一次，检测PB0引脚的状态，根据脉冲数量来计算出PID控制器的输出值，并改变PA8引脚的PWM输出占空比。

volatile uint16_t pulse_cnt = 0;
volatile float error = 0, pre_error = 0, integral = 0, derivative = 0;
const float kp = 1.0, ki = 0.01, kd = 0.1;
volatile float output = 0;

void TIM2_IRQHandler(void)
{
    if (TIM_GetITStatus(TIM2, TIM_IT_Update) != RESET)
    {
        TIM_ClearITPendingBit(TIM2, TIM_IT_Update);

        if (GPIO_ReadInputDataBit(GPIOB, GPIO_Pin_0) == Bit_SET)
        {
            pulse_cnt++;
        }

        error = TARGET - pulse_cnt;
        integral += error * 0.001;
        derivative = (error - pre_error) / 0.001;
        output = kp * error + ki * integral + kd * derivative;

        if (output > 1000) output = 1000;
        if (output < 0) output = 0;

        TIM_SetCompare1(TIM1, output);
    }
}

最后，在主函数中初始化GPIO和定时器，并使能定时器中断。

int main(void)
{
    GPIO_Init();
    TIM2_Init();

    NVIC_InitTypeDef NVIC_InitStructure;
    NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    while (1)
    {
    }
}

以上是一个基本的PID控制电机的程序，具体的参数需要根据实际情况进行调整。