用STM32F103C8T6写PWM控制步进马达的示例程序

我可以回答这个问题。以下是一个用STM32F103C8T6写PWM控制步进马达的示例程序：

#include "stm32f10x.h"

#define FREQ 200 // PWM频率
#define STEPS 100 // 步数

int main(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;

// 使能时钟
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

// 配置引脚
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);

// 配置定时器
TIM_TimeBaseStructure.TIM_Period = (SystemCoreClock / FREQ) - 1;
TIM_TimeBaseStructure.TIM_Prescaler = 0;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

// 配置PWM输出
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = (SystemCoreClock / FREQ) / 2;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OC1Init(TIM2, &TIM_OCInitStructure);
TIM_OC2Init(TIM2, &TIM_OCInitStructure);
TIM_OC3Init(TIM2, &TIM_OCInitStructure);
TIM_OC4Init(TIM2, &TIM_OCInitStructure);

// 启动定时器
TIM_Cmd(TIM2, ENABLE);

// 步进马达控制
int i;
for (i = 0; i < STEPS; i++) {
TIM_SetCompare1(TIM2, (SystemCoreClock / FREQ) * i / STEPS);
TIM_SetCompare2(TIM2, (SystemCoreClock / FREQ) * (STEPS - i) / STEPS);
TIM_SetCompare3(TIM2, (SystemCoreClock / FREQ) * i / STEPS);
TIM_SetCompare4(TIM2, (SystemCoreClock / FREQ) * (STEPS - i) / STEPS);
delay_ms(5); // 延时5ms
}

while (1);
}

请注意，此示例程序仅供参考，具体实现可能会因硬件和软件环境的不同而有所不同。