stm32f103c8t6用pid算法写一个五路的循迹小车（四个直流减速电机）

循迹小车是一种常见的机器人，它通过感知地面上的黑色线条，实现自动寻路的功能。PID算法是一种常见的控制算法，用于控制机器人的行动，下面我们来介绍如何使用STM32F103C8T6控制五路电机的循迹小车。

首先，需要准备以下硬件材料：

- STM32F103C8T6开发板
- L298N电机驱动模块
- TCRT5000红外线传感器5个
- 直流减速电机4个
- 小车底盘

接下来，我们需要进行以下步骤：

1. 连接硬件

将L298N电机驱动模块与STM32F103C8T6开发板连接，连接方式如下：

| L298N引脚 | STM32F103C8T6引脚 |
|---------|------------------|
| ENA | PB0 |
| IN1 | PB1 |
| IN2 | PB2 |
| IN3 | PB10 |
| IN4 | PB11 |
| ENB | PB12 |

将TCRT5000红外线传感器连接到STM32F103C8T6开发板的引脚上，连接方式如下：

| TCRT5000引脚 | STM32F103C8T6引脚 |
|-------------|------------------|
| VCC | 5V |
| GND | GND |
| DO | PA0~PA4 |

将直流减速电机连接到L298N电机驱动模块上，连接方式如下：

| 直流减速电机引脚 | L298N引脚 |
|----------------|----------|
| 正极 | OUT1 |
| 负极 | OUT2 |
| 正极 | OUT3 |
| 负极 | OUT4 |

2. 编写代码

接下来，我们需要编写代码来实现循迹小车的功能。首先，我们需要对红外线传感器进行初始化，然后读取传感器的数据，并根据数据来控制小车的移动方向。具体代码如下：

#include "stm32f10x.h"

void delay_us(u32 nus)
{
    u32 i;
    for(i=0;i<nus*8;i++);
}

void delay_ms(u16 nms)
{
    u16 i;
    for(i=0;i<nms;i++)
        delay_us(1000);
}

void init_GPIO(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB, ENABLE);
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3 | GPIO_Pin_4;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_10 | GPIO_Pin_11 | GPIO_Pin_12;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_Init(GPIOB, &GPIO_InitStructure);
}

void motor_forward(u8 speed)
{
    GPIO_WriteBit(GPIOB, GPIO_Pin_1, Bit_RESET);
    GPIO_WriteBit(GPIOB, GPIO_Pin_2, Bit_SET);
    GPIO_WriteBit(GPIOB, GPIO_Pin_10, Bit_RESET);
    GPIO_WriteBit(GPIOB, GPIO_Pin_11, Bit_SET);
    TIM_SetCompare3(TIM2, speed);
    TIM_SetCompare4(TIM2, speed);
    TIM_SetCompare1(TIM3, speed);
    TIM_SetCompare2(TIM3, speed);
}

void motor_backward(u8 speed)
{
    GPIO_WriteBit(GPIOB, GPIO_Pin_1, Bit_SET);
    GPIO_WriteBit(GPIOB, GPIO_Pin_2, Bit_RESET);
    GPIO_WriteBit(GPIOB, GPIO_Pin_10, Bit_SET);
    GPIO_WriteBit(GPIOB, GPIO_Pin_11, Bit_RESET);
    TIM_SetCompare3(TIM2, speed);
    TIM_SetCompare4(TIM2, speed);
    TIM_SetCompare1(TIM3, speed);
    TIM_SetCompare2(TIM3, speed);
}

void motor_left(u8 speed)
{
    GPIO_WriteBit(GPIOB, GPIO_Pin_1, Bit_RESET);
    GPIO_WriteBit(GPIOB, GPIO_Pin_2, Bit_SET);
    GPIO_WriteBit(GPIOB, GPIO_Pin_10, Bit_SET);
    GPIO_WriteBit(GPIOB, GPIO_Pin_11, Bit_RESET);
    TIM_SetCompare3(TIM2, speed);
    TIM_SetCompare4(TIM2, speed);
    TIM_SetCompare1(TIM3, speed);
    TIM_SetCompare2(TIM3, speed);
}

void motor_right(u8 speed)
{
    GPIO_WriteBit(GPIOB, GPIO_Pin_1, Bit_SET);
    GPIO_WriteBit(GPIOB, GPIO_Pin_2, Bit_RESET);
    GPIO_WriteBit(GPIOB, GPIO_Pin_10, Bit_RESET);
    GPIO_WriteBit(GPIOB, GPIO_Pin_11, Bit_SET);
    TIM_SetCompare3(TIM2, speed);
    TIM_SetCompare4(TIM2, speed);
    TIM_SetCompare1(TIM3, speed);
    TIM_SetCompare2(TIM3, speed);
}

void motor_stop(void)
{
    GPIO_WriteBit(GPIOB, GPIO_Pin_1, Bit_RESET);
    GPIO_WriteBit(GPIOB, GPIO_Pin_2, Bit_RESET);
    GPIO_WriteBit(GPIOB, GPIO_Pin_10, Bit_RESET);
    GPIO_WriteBit(GPIOB, GPIO_Pin_11, Bit_RESET);
    TIM_SetCompare3(TIM2, 0);
    TIM_SetCompare4(TIM2, 0);
    TIM_SetCompare1(TIM3, 0);
    TIM_SetCompare2(TIM3, 0);
}

u8 read_sensor(void)
{
    u8 i,sensor_data=0;
    for(i=0;i<5;i++)
    {
        if(GPIO_ReadInputDataBit(GPIOA,1<<i)==0)
            sensor_data|=1<<i;
    }
    return sensor_data;
}

void pid_control(u8 sensor_data)
{
    s16 error;
    s16 p_term;
    s16 i_term;
    s16 d_term;
    static s16 last_error=0;
    static s16 integral=0;

    error=sensor_data-0x0F;

    p_term=error*2;
    integral+=error;
    i_term=integral*0.001;
    d_term=(error-last_error)*40;

    last_error=error;

    s16 speed=p_term+i_term+d_term;

    if(speed>255)
        speed=255;
    if(speed<-255)
        speed=-255;

    if(speed>0)
        motor_forward(speed);
    else if(speed<0)
        motor_backward(-speed);
    else
        motor_stop();
}

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

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1 | RCC_APB2Periph_TIM8, ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2 | RCC_APB1Periph_TIM3, ENABLE);

    TIM_TimeBaseStructure.TIM_Period = 999;
    TIM_TimeBaseStructure.TIM_Prescaler = 71;
    TIM_TimeBaseStructure.TIM_ClockDivision = 0;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;

    TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);
    TIM_TimeBaseInit(TIM8, &TIM_TimeBaseStructure);
    TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
    TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);

    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(TIM1, &TIM_OCInitStructure);
    TIM_OC2Init(TIM1, &TIM_OCInitStructure);
    TIM_OC3Init(TIM1, &TIM_OCInitStructure);
    TIM_OC4Init(TIM1, &TIM_OCInitStructure);

    TIM_OC1Init(TIM8, &TIM_OCInitStructure);
    TIM_OC2Init(TIM8, &TIM_OCInitStructure);
    TIM_OC3Init(TIM8, &TIM_OCInitStructure);
    TIM_OC4Init(TIM8, &TIM_OCInitStructure);

    TIM_OC3Init(TIM2, &TIM_OCInitStructure);
    TIM_OC4Init(TIM2, &TIM_OCInitStructure);

    TIM_OC1Init(TIM3, &TIM_OCInitStructure);
    TIM_OC2Init(TIM3, &TIM_OCInitStructure);

    TIM_Cmd(TIM1, ENABLE);
    TIM_Cmd(TIM8, ENABLE);
    TIM_Cmd(TIM2, ENABLE);
    TIM_Cmd(TIM3, ENABLE);

    init_GPIO();

    while(1)
    {
        u8 sensor_data=read_sensor();
        pid_control(sensor_data);
        delay_ms(10);
    }
}

3. 调试测试

将代码烧录到STM32F103C8T6开发板上，然后将小车放在地面上，让它自行行驶，观察小车的行动是否符合预期。如果出现异常情况，可以通过调试代码来解决问题。

这样，我们就成功地使用STM32F103C8T6控制五路电机的循迹小车了。