写一个stm32f103rct6做MCU使用pwm控制步进电机速度程序

以下是一个简单的使用PWM控制步进电机速度的程序：

#include "stm32f10x.h"

#define PWM_TIM TIM3
#define PWM_TIM_RCC RCC_APB1Periph_TIM3
#define PWM_GPIO_RCC RCC_APB2Periph_GPIOA
#define PWM_GPIO GPIOA
#define PWM_PIN GPIO_Pin_6

#define DIR_GPIO_RCC RCC_APB2Periph_GPIOA
#define DIR_GPIO GPIOA
#define DIR_PIN GPIO_Pin_7

#define STEPS_PER_REV 200

void PWM_Init(void);
void DIR_Init(void);
void Delay(uint32_t nCount);

int main(void)
{
    uint32_t i;
    uint16_t duty_cycle = 0;

    PWM_Init();
    DIR_Init();

    while (1)
    {
        for (i = 0; i < STEPS_PER_REV; i++)
        {
            // Set direction to clockwise
            GPIO_ResetBits(DIR_GPIO, DIR_PIN);

            // Set duty cycle
            duty_cycle += 100;
            if (duty_cycle > PWM_TIM->ARR)
            {
                duty_cycle = 0;
            }
            PWM_TIM->CCR1 = duty_cycle;

            // Delay for a short time
            Delay(1000);
        }
    }
}

void PWM_Init(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    TIM_OCInitTypeDef TIM_OCInitStructure;

    // Enable TIM3 and GPIOA clock
    RCC_APB1PeriphClockCmd(PWM_TIM_RCC, ENABLE);
    RCC_APB2PeriphClockCmd(PWM_GPIO_RCC, ENABLE);

    // Configure PWM pin as alternate function push-pull
    GPIO_InitStructure.GPIO_Pin = PWM_PIN;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(PWM_GPIO, &GPIO_InitStructure);

    // Configure TIM3 for PWM generation
    TIM_TimeBaseStructure.TIM_Period = 999;
    TIM_TimeBaseStructure.TIM_Prescaler = 71;
    TIM_TimeBaseStructure.TIM_ClockDivision = 0;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(PWM_TIM, &TIM_TimeBaseStructure);

    // Configure PWM output channel 1
    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_Pulse = 0;
    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
    TIM_OC1Init(PWM_TIM, &TIM_OCInitStructure);
    TIM_OC1PreloadConfig(PWM_TIM, TIM_OCPreload_Enable);

    // Enable TIM3
    TIM_Cmd(PWM_TIM, ENABLE);
}

void DIR_Init(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;

    // Enable GPIOA clock
    RCC_APB2PeriphClockCmd(DIR_GPIO_RCC, ENABLE);

    // Configure DIR pin as output push-pull
    GPIO_InitStructure.GPIO_Pin = DIR_PIN;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(DIR_GPIO, &GPIO_InitStructure);
}

void Delay(uint32_t nCount)
{
    uint32_t i;
    for (i = 0; i < nCount; i++);
}

上述程序中，使用了TIM3的PWM功能控制步进电机的速度。PWM输出通过PA6引脚输出，方向控制通过PA7引脚输出。程序中每次循环增加PWM占空比，从而加快步进电机的运动速度。在每个步进电机的步进角度完成后，程序会延时一段时间，以便电机停止运动。