开发板连接方式如下图：
    项目3 红外遥控小车 - 图1

    马达 马达驱动板
    马达1（右轮）接近地面引脚 OUT1
    马达1（右轮）接近底板引脚 OUT2
    马达2（左轮）接近地面引脚 OUT3
    马达2（左轮）接近底板引脚 OUT4
    马达驱动板 Arduino开发板
    IN1 4
    IN2 5
    IN3 6
    IN4 7
    马达驱动板 外接电源
    VCC 电源正极
    GND 电源负极和Arduino GND
    5V Arduino Vin引脚
    红外模块 Arduino开发板
    IN D8
    VCC 5V
    GND GND

    小车组装效果图如下：

    上部：
    项目3 红外遥控小车 - 图2

    底部：
    项目3 红外遥控小车 - 图3

    对应代码如下：

    1. // 库源码放在本项目所在目录
    2. #include "IRremote.h"
    4. // 设置接收IRDA数据的引脚
    5. int RECV_PIN = 8;
    7. // 初始化IRDA模块
    8. IRrecv irrecv(RECV_PIN);
    9. // 准备读取数据的数据结构
    10. decode_results results;
    13. //使用L298N驱动板
    14. // IN1连接引脚4
    15. // IN2连接引脚5
    16. // IN3连接引脚6
    17. // IN4连接引脚7
    18. int IN1=4;
    19. int IN2=5;
    20. int IN3=6;
    21. int IN4=7;
    23. const int WHEEL_MOVE_IDEL     = 0;
    24. const int WHEEL_MOVE_FORWARD  = 1;
    25. const int WHEEL_MOVE_BACKWARD = 2;
    27. const long IRDA_ACTION_FORWARD  = 0x00FF18E7; //2
    28. const long IRDA_ACTION_BACKWARD = 0x00FF4AB5; //8
    29. const long IRDA_ACTION_LEFT     = 0x00FF10EF; //4
    30. const long IRDA_ACTION_RIGHT    = 0x00FF5AA5; // 6
    31. const long IRDA_ACTION_STOP     = 0x00FF38C7; // 5
    33. unsigned long last = millis();
    35. void setup() {
    37.   //初始化电机不动
    38.   pinMode(IN1, OUTPUT);
    39.   digitalWrite(IN1, HIGH);
    40.   pinMode(IN2, OUTPUT);
    41.   digitalWrite(IN2, HIGH);
    42.   pinMode(IN3, OUTPUT);
    43.   digitalWrite(IN3, HIGH);
    44.   pinMode(IN4, OUTPUT);
    45.   digitalWrite(IN4, HIGH);
    47.   // 初始化引脚
    48.   pinMode(RECV_PIN, INPUT);
    49.   // 初始化串口
    50.   Serial.begin(9600);
    51.   // 启动IRDA接收模块，随时接收数据
    52.   irrecv.enableIRIn(); 
    54. }
    56. void loop() {
    58.   if (millis() - last < 250) 
    59.   {
    60.     return;
    61.   }
    62.   last = millis();
    64.   bool shouldMove = false;
    65.   bool shouldTurn = false;
    66.   bool shouldKeep = false;
    68.   //读取红外输入信息
    69.   if (irrecv.decode(&results)) {
    70.     Serial.println(results.value, HEX);
    71.     switch(results.value) {
    72.       case IRDA_ACTION_FORWARD:
    73.         goForward();
    74.         Serial.println("go forward");
    75.         shouldMove = true;
    76.         break;
    78.       case IRDA_ACTION_BACKWARD:
    79.         goBackward();
    80.         Serial.println("go backward");
    81.         shouldMove = true;
    82.         break;
    84.       case IRDA_ACTION_LEFT:
    85.         turnLeft();
    86.         Serial.println("turn left");
    87.         shouldTurn = true;
    88.         break;
    90.       case IRDA_ACTION_RIGHT:
    91.         turnRight();
    92.         Serial.println("turn right");
    93.         shouldTurn = true;
    94.         break;
    96.       case IRDA_ACTION_STOP:
    97.         stopMove();
    98.         Serial.println("stop");
    99.         break;
    101.       default:
    102.         shouldKeep = true;
    103.         break;
    105.     }
    106.     irrecv.resume();
    107.   }
    109.   if(!shouldTurn && !shouldMove && !shouldKeep){
    110.     keepIdle();
    111.   }
    113. }
    115. void keepIdle() {
    116.   rightMove(WHEEL_MOVE_IDEL);
    117.   leftMove(WHEEL_MOVE_IDEL);
    118. }
    120. void goForward() {
    121.   rightMove(WHEEL_MOVE_FORWARD);
    122.   leftMove(WHEEL_MOVE_FORWARD);
    123. }
    125. void goBackward() {
    126.   rightMove(WHEEL_MOVE_BACKWARD);
    127.   leftMove(WHEEL_MOVE_BACKWARD);
    128. }
    130. void turnLeft(){
    131.   rightMove(WHEEL_MOVE_FORWARD);
    132.   leftMove(WHEEL_MOVE_IDEL);
    133. }
    135. void turnRight(){
    136.   rightMove(WHEEL_MOVE_IDEL);
    137.   leftMove(WHEEL_MOVE_FORWARD);
    138. }
    140. void stopMove(){
    141.   rightMove(WHEEL_MOVE_IDEL);
    142.   leftMove(WHEEL_MOVE_IDEL);
    143. }
    145. void rightMove(int state) {
    146.   switch(state){
    147.     case WHEEL_MOVE_FORWARD:
    148.       digitalWrite(IN1,HIGH);
    149.       digitalWrite(IN2,LOW);
    150.       break;
    152.     case WHEEL_MOVE_BACKWARD:
    153.       digitalWrite(IN1,LOW);
    154.       digitalWrite(IN2,HIGH);
    155.       break;
    157.     case WHEEL_MOVE_IDEL:
    158.       digitalWrite(IN1,LOW);
    159.       digitalWrite(IN2,LOW);
    160.       break;
    162.   }
    163. }
    165. void leftMove(int state) {
    166.   switch(state){
    167.     case WHEEL_MOVE_FORWARD:
    168.       digitalWrite(IN3,HIGH);
    169.       digitalWrite(IN4,LOW);
    170.       break;
    172.     case WHEEL_MOVE_BACKWARD:
    173.       digitalWrite(IN3,LOW);
    174.       digitalWrite(IN4,HIGH);
    175.       break;
    177.     case WHEEL_MOVE_IDEL:
    178.       digitalWrite(IN3,LOW);
    179.       digitalWrite(IN4,LOW);
    180.       break;
    182.   }
    183. }