arduino nano 小车，三个循迹，全代码

好的，以下是一个基于Arduino Nano的小车循迹代码示例。这个示例使用了三个循迹传感器来控制小车的运动。

### 硬件连接
- 左循迹传感器连接到A0
- 中循迹传感器连接到A1
- 右循迹传感器连接到A2
- 左电机控制引脚连接到D5和D6
- 右电机控制引脚连接到D9和D10

### 代码示例

// 定义循迹传感器引脚
const int leftSensorPin = A0;
const int middleSensorPin = A1;
const int rightSensorPin = A2;

// 定义电机控制引脚
const int leftMotorForward = 5;
const int leftMotorBackward = 6;
const int rightMotorForward = 9;
const int rightMotorBackward = 10;

void setup() {
  // 初始化串口通信
  Serial.begin(9600);

  // 初始化传感器引脚
  pinMode(leftSensorPin, INPUT);
  pinMode(middleSensorPin, INPUT);
  pinMode(rightSensorPin, INPUT);

  // 初始化电机控制引脚
  pinMode(leftMotorForward, OUTPUT);
  pinMode(leftMotorBackward, OUTPUT);
  pinMode(rightMotorForward, OUTPUT);
  pinMode(rightMotorBackward, OUTPUT);
}

void loop() {
  // 读取传感器值
  int leftSensorValue = digitalRead(leftSensorPin);
  int middleSensorValue = digitalRead(middleSensorPin);
  int rightSensorValue = digitalRead(rightSensorPin);

  // 打印传感器值到串口监视器
  Serial.print("Left Sensor: ");
  Serial.print(leftSensorValue);
  Serial.print(" Middle Sensor: ");
  Serial.print(middleSensorValue);
  Serial.print(" Right Sensor: ");
  Serial.println(rightSensorValue);

  // 根据传感器值控制电机
  if (middleSensorValue == LOW) {
    // 中间传感器检测到黑线，直行
    moveForward();
  } else if (leftSensorValue == LOW) {
    // 左边传感器检测到黑线，向左转
    turnLeft();
  } else if (rightSensorValue == LOW) {
    // 右边传感器检测到黑线，向右转
    turnRight();
  } else {
    // 没有检测到黑线，停止
    stopMoving();
  }
}

void moveForward() {
  digitalWrite(leftMotorForward, HIGH);
  digitalWrite(leftMotorBackward, LOW);
  digitalWrite(rightMotorForward, HIGH);
  digitalWrite(rightMotorBackward, LOW);
}

void turnLeft() {
  digitalWrite(leftMotorForward, LOW);
  digitalWrite(leftMotorBackward, LOW);
  digitalWrite(rightMotorForward, HIGH);
  digitalWrite(rightMotorBackward, LOW);
}

void turnRight() {
  digitalWrite(leftMotorForward, HIGH);
  digitalWrite(leftMotorBackward, LOW);
  digitalWrite(rightMotorForward, LOW);
  digitalWrite(rightMotorBackward, LOW);
}

void stopMoving() {
  digitalWrite(leftMotorForward, LOW);
  digitalWrite(leftMotorBackward, LOW);
  digitalWrite(rightMotorForward, LOW);
  digitalWrite(rightMotorBackward, LOW);
}

### 代码说明
1. **初始化部分**：在`setup()`函数中，初始化串口通信和所有引脚的模式。
2. **主循环部分**：在`loop()`函数中，读取三个循迹传感器的值，并根据传感器的状态控制电机的运动。
3. **电机控制函数**：定义了四个函数`moveForward()`、`turnLeft()`、`turnRight()`和`stopMoving()`，分别用于控制小车前进、左转、右转和停止。

希望这个示例对你有所帮助！