写一个stm32控制舵机的代码

以下是一个使用STM32控制舵机的示例代码，假设使用的是PWM输出控制舵机角度：

#include "stm32f4xx.h"

#define SERVO_PWM_PIN GPIO_Pin_9
#define SERVO_PWM_PORT GPIOA
#define SERVO_PWM_TIM TIM1

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

  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);

  GPIO_InitStructure.GPIO_Pin = SERVO_PWM_PIN;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
  GPIO_Init(SERVO_PWM_PORT, &GPIO_InitStructure);

  GPIO_PinAFConfig(SERVO_PWM_PORT, GPIO_PinSource9, GPIO_AF_TIM1);

  TIM_TimeBaseStructure.TIM_Prescaler = 83; // 84MHz / (83+1) = 1MHz
  TIM_TimeBaseStructure.TIM_Period = 20000; // 1MHz / 20000 = 50Hz
  TIM_TimeBaseStructure.TIM_ClockDivision = 0;
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
  TIM_TimeBaseInit(SERVO_PWM_TIM, &TIM_TimeBaseStructure);

  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_Pulse = 1500; // 1.5ms pulse for center position
  TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
  TIM_OC1Init(SERVO_PWM_TIM, &TIM_OCInitStructure);

  TIM_Cmd(SERVO_PWM_TIM, ENABLE);
  TIM_CtrlPWMOutputs(SERVO_PWM_TIM, ENABLE);
}

void setServoPosition(uint16_t position) {
  if (position < 500) {
    position = 500;
  } else if (position > 2500) {
    position = 2500;
  }
  TIM_SetCompare1(SERVO_PWM_TIM, position);
}

int main(void) {
  initServoPWM();

  while(1) {
    setServoPosition(1500); // set to center position
    delay_ms(1000);
    setServoPosition(2000); // set to max position
    delay_ms(1000);
    setServoPosition(1000); // set to min position
    delay_ms(1000);
  }
}

这个代码使用TIM1的PWM输出控制PA9引脚的电平，进而控制舵机的角度。代码中使用了一个名为`setServoPosition()`的函数，它将传入的角度值转换为对应的PWM脉宽，并设置到TIM1的CCR1寄存器中，从而控制舵机的位置。在上面的示例中，舵机的运动范围是500-2500us，中心位置是1500us。