写一个基于stm32f103c8t6的给电机控制速度的pid算法的代码

以下是一个基于STM32F103C8T6的PID算法控制电机速度的代码示例：

#include "stm32f10x.h"

// 定义PID结构体
typedef struct 
{
  float Kp;
  float Ki;
  float Kd;
  float error;
  float last_error;
  float integral;
  float derivative;
} PID_TypeDef;

// 定义PID参数
#define KP 0.5
#define KI 0.2
#define KD 0.1

// 定义PWM输出引脚
#define PWM_PIN GPIO_Pin_9
#define PWM_GPIO GPIOC

// 定义编码器读取引脚
#define ENCODER_PIN GPIO_Pin_7
#define ENCODER_GPIO GPIOA

// 定义电机速度限制
#define MAX_SPEED 1000

// 初始化PID结构体
PID_TypeDef pid = {KP, KI, KD, 0, 0, 0, 0};

// 初始化PWM
void init_pwm(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;
  TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
  TIM_OCInitTypeDef TIM_OCInitStructure;

  // 打开GPIO和TIM时钟
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC | RCC_APB2Periph_AFIO, ENABLE);
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);

  // 配置GPIO为复用推挽输出
  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);

  // 配置TIM为PWM模式
  TIM_TimeBaseStructure.TIM_Prescaler = 72 - 1;
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
  TIM_TimeBaseStructure.TIM_Period = MAX_SPEED - 1;
  TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
  TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);

  // 配置TIM通道为PWM输出模式
  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(TIM3, &TIM_OCInitStructure);

  // 启动TIM
  TIM_Cmd(TIM3, ENABLE);
}

// 初始化编码器
void init_encoder(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;
  TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
  TIM_ICInitTypeDef TIM_ICInitStructure;

  // 打开GPIO和TIM时钟
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE);
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

  // 配置GPIO为浮空输入
  GPIO_InitStructure.GPIO_Pin = ENCODER_PIN;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
  GPIO_Init(ENCODER_GPIO, &GPIO_InitStructure);

  // 配置TIM为编码器模式
  TIM_TimeBaseStructure.TIM_Prescaler = 0;
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
  TIM_TimeBaseStructure.TIM_Period = 65535;
  TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
  TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

  // 配置TIM输入捕获通道
  TIM_ICInitStructure.TIM_Channel = TIM_Channel_2;
  TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;
  TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
  TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;
  TIM_ICInitStructure.TIM_ICFilter = 0;
  TIM_ICInit(TIM2, &TIM_ICInitStructure);

  // 启动TIM
  TIM_Cmd(TIM2, ENABLE);
}

// 获取编码器读数
int get_encoder_count(void)
{
  return TIM_GetCounter(TIM2);
}

// 更新PID计算结果
int update_pid(int target_speed, int current_speed)
{
  pid.error = target_speed - current_speed;
  pid.integral += pid.error;
  pid.derivative = pid.error - pid.last_error;
  pid.last_error = pid.error;

  float output = pid.Kp * pid.error + pid.Ki * pid.integral + pid.Kd * pid.derivative;

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

  TIM_SetCompare1(TIM3, output);

  return output;
}

int main(void)
{
  // 初始化PWM和编码器
  init_pwm();
  init_encoder();

  // 设置目标速度和当前速度
  int target_speed = 500;
  int current_speed = 0;

  while (1)
  {
    // 读取编码器计数
    int encoder_count = get_encoder_count();

    // 计算当前速度
    current_speed = encoder_count * 10;

    // 使用PID控制电机速度
    update_pid(target_speed, current_speed);
  }
}

以上代码仅供参考，具体实现需要根据电机控制器的具体要求进行调整。