三个红外对射传感器的数字输出端口分别连接到PA11、PA12、PA13，三个舵机的信号线分别连接在PB11、PB12、PB13，使用C语言使STM32F103C8系列单片机实现当红外对射传感器检测到前方有物体时控制舵机旋转90度

可以使用以下代码实现：

#include "stm32f10x.h"

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

    // Enable GPIOA and GPIOB clocks
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB, ENABLE);

    // Configure PA11, PA12, and PA13 as input pins
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11 | GPIO_Pin_12 | GPIO_Pin_13;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    // Configure PB11, PB12, and PB13 as output pins
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11 | GPIO_Pin_12 | GPIO_Pin_13;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOB, &GPIO_InitStructure);

    // Enable TIM2 clock
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

    // Configure TIM2 to generate PWM signals
    TIM_TimeBaseStructure.TIM_Period = 20000 - 1; // 20ms period
    TIM_TimeBaseStructure.TIM_Prescaler = 72 - 1; // 1us resolution
    TIM_TimeBaseStructure.TIM_ClockDivision = 0;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

    // Configure TIM2 channel 4 to generate PWM signal for PB11
    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_Pulse = 1500; // 1.5ms pulse width (centered)
    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
    TIM_OC4Init(TIM2, &TIM_OCInitStructure);
    TIM_OC4PreloadConfig(TIM2, TIM_OCPreload_Enable);

    // Configure TIM2 channel 3 to generate PWM signal for PB12
    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_Pulse = 1500; // 1.5ms pulse width (centered)
    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
    TIM_OC3Init(TIM2, &TIM_OCInitStructure);
    TIM_OC3PreloadConfig(TIM2, TIM_OCPreload_Enable);

    // Configure TIM2 channel 2 to generate PWM signal for PB13
    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_Pulse = 1500; // 1.5ms pulse width (centered)
    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
    TIM_OC2Init(TIM2, &TIM_OCInitStructure);
    TIM_OC2PreloadConfig(TIM2, TIM_OCPreload_Enable);

    // Start TIM2
    TIM_Cmd(TIM2, ENABLE);

    while (1)
    {
        // Check if all three infrared sensors detect an object
        if (GPIO_ReadInputDataBit(GPIOA, GPIO_Pin_11) &&
            GPIO_ReadInputDataBit(GPIOA, GPIO_Pin_12) &&
            GPIO_ReadInputDataBit(GPIOA, GPIO_Pin_13))
        {
            // Rotate all three servos 90 degrees
            TIM_SetCompare4(TIM2, 2250); // PB11
            TIM_SetCompare3(TIM2, 2250); // PB12
            TIM_SetCompare2(TIM2, 2250); // PB13
        }
        else
        {
            // Reset all three servos to center position
            TIM_SetCompare4(TIM2, 1500); // PB11
            TIM_SetCompare3(TIM2, 1500); // PB12
            TIM_SetCompare2(TIM2, 1500); // PB13
        }
    }
}