stm32基于库函数上位机来控制舵机

好的，以下是一个基于库函数的 STM32 上位机控制舵机的程序示例：

#include "stm32f10x.h"
#include "stdio.h"

#define USART USART1
#define USART_CLK RCC_APB2Periph_USART1
#define USART_GPIO GPIOA
#define USART_GPIO_CLK RCC_APB2Periph_GPIOA
#define USART_RxPin GPIO_Pin_10
#define USART_TxPin GPIO_Pin_9

#define PWM_TIM TIM2
#define PWM_TIM_CLK RCC_APB1Periph_TIM2
#define PWM_GPIO GPIOA
#define PWM_GPIO_CLK RCC_APB2Periph_GPIOA
#define PWM_Pin GPIO_Pin_1
#define PWM_PinSource GPIO_PinSource1
#define PWM_TIM_OC TIM_OC2InitTypeDef
#define PWM_TIM_OCPreloadConfig TIM_OC2PreloadConfig

#define BAUDRATE 115200

void USART_Configuration(void);
void PWM_Configuration(void);
void Delay(uint32_t nCount);
void USART_SendString(char* s);

int main(void)
{
    USART_Configuration();
    PWM_Configuration();

    uint16_t pulse_width = 1500; // 初始脉宽为 1.5ms
    char buffer[10];

    while (1)
    {
        if (USART_GetFlagStatus(USART, USART_FLAG_RXNE) == SET)
        {
            char ch = USART_ReceiveData(USART);
            if (ch == '+')
            {
                pulse_width += 50; // 每次增加 50us
                if (pulse_width > 2500)
                    pulse_width = 2500;
            }
            else if (ch == '-')
            {
                pulse_width -= 50; // 每次减少 50us
                if (pulse_width < 500)
                    pulse_width = 500;
            }

            sprintf(buffer, "%d\r\n", pulse_width);
            USART_SendString(buffer);

            PWM_TIM_OC.TIM_Pulse = pulse_width;
            TIM_OC2Init(PWM_TIM, &PWM_TIM_OC);
            PWM_TIM_OCPreloadConfig(PWM_TIM, TIM_OCPreload_Enable);

            Delay(10);
        }
    }
}

void USART_Configuration(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    USART_InitTypeDef USART_InitStructure;

    // 配置时钟
    RCC_APB2PeriphClockCmd(USART_GPIO_CLK | USART_CLK, ENABLE);

    // 配置 USART 的 GPIO 引脚
    GPIO_InitStructure.GPIO_Pin = USART_TxPin;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(USART_GPIO, &GPIO_InitStructure);

    GPIO_InitStructure.GPIO_Pin = USART_RxPin;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
    GPIO_Init(USART_GPIO, &GPIO_InitStructure);

    // 配置 USART
    USART_InitStructure.USART_BaudRate = BAUDRATE;
    USART_InitStructure.USART_WordLength = USART_WordLength_8b;
    USART_InitStructure.USART_StopBits = USART_StopBits_1;
    USART_InitStructure.USART_Parity = USART_Parity_No;
    USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
    USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
    USART_Init(USART, &USART_InitStructure);

    USART_Cmd(USART, ENABLE);
}

void PWM_Configuration(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    PWM_TIM_OC TIM_OCInitStructure;

    // 配置时钟
    RCC_APB2PeriphClockCmd(PWM_GPIO_CLK, ENABLE);
    RCC_APB1PeriphClockCmd(PWM_TIM_CLK, ENABLE);

    // 配置 PWM 的 GPIO 引脚
    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 PWM 的 TIM
    TIM_TimeBaseStructure.TIM_Period = 20000 - 1; // PWM 周期为 20ms
    TIM_TimeBaseStructure.TIM_Prescaler = 72 - 1; // 时钟预分频为 72
    TIM_TimeBaseStructure.TIM_ClockDivision = 0;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(PWM_TIM, &TIM_TimeBaseStructure);

    // 配置 PWM 的 TIM 的通道 2
    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_Pulse = 1500; // PWM 脉宽为 1.5ms
    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
    TIM_OC2Init(PWM_TIM, &TIM_OCInitStructure);
    PWM_TIM_OCPreloadConfig(PWM_TIM, TIM_OCPreload_Enable);

    TIM_Cmd(PWM_TIM, ENABLE);
}

void Delay(uint32_t nCount)
{
    for (uint32_t i = 0; i < nCount * 72000; ++i);
}

void USART_SendString(char* s)
{
    while (*s)
    {
        while (USART_GetFlagStatus(USART, USART_FLAG_TXE) == RESET);
        USART_SendData(USART, *s++);
    }
}

在程序中需要注意以下几点：

1. 需要配置 USART 和 PWM 的时钟；
2. 需要配置 USART 和 PWM 的 GPIO 引脚；
3. 需要配置 USART 和 PWM 的初始化参数；
4. 在主循环中通过 USART 接收上位机传来的数据，并根据数据计算出 PWM 脉宽值；
5. 每次更新 PWM 脉宽值后需要等待一段时间，以确保舵机能够稳定工作。