上次带大家利用ESP8266自制了wifi控制的LED点阵屏幕，大家觉得怎么样呢？ 手把手教你用wifi控制显示屏！ESP8266实践指南（一）

今天我们来做点更有意思的~ wifi遥控小车！

一、所需材料

• ESP8266 NodeMCU开发板：这次我们使用CP2102芯片的那款NodeMCU，优点是体积更小一点，更适合小车这种体积受限的场景。
• L9110电机控制模块
• 面包板：方便接线
• 两轮小车底盘套装，包含：塑料底盘，电机x2, 轮子x2，万向轮，5号电池盒
• 公对公杜邦线若干
• 5号电池4节
• 手机移动电源一个

二、组装小车

先按照说明书把小车底盘套装组装起来：

然后将ESP8266，L9110固定在面包板上，并按照线路图连接：

实际接线效果大致如图：

固定电池盒和充电宝：

4节串联的5号电池用于给L9110供电，而充电宝用于通过usb接口给NodeMCU开发板供电。

一开始，我尝试了直接使用充电宝给NodeMCU开发板供电，然后L9110的VCC接NodeMCU的VIN，GND接NodeMCU的GND来供电。这样的话，简单便捷，不需要两套供电。但是不幸的是，动力电路走开发板的VIN确实会有问题：在电机运转一会儿后，开发板会重启。

于是后来我还是用上了电池盒，用电池盒给L9110供电，正负极分别接VCC, GND就可以了。

在连接好开发板，电机，电源之后，摆放好各个部件，用双面胶固定到位即可。有条件的话，电机的正负电源线建议使用电烙铁和焊锡固定好，防止震动导致松动。

三、上传代码

有关ESP8266的开发环境配置在这里不在赘述，之前没有设置的朋友看这里~ 很简单哦~

十块钱入门物联网！ESP8266新手指南

将以下代码复制到Arduino IDE:

// Simple WiFi-controlled car on NodeMCU and L9110 motor drive board
// OrangeZero 零度橙子@头条
// source code modified from Alan Wang@hackster.io


#include <ESP8266WiFi.h>
#include <ESP8266WebServer.h>

// WiFi settings
#define WIFI_MODE           1                     // 1: AP模式，NodeMCU自身起一个wifi信号；2：SA模式，NodeMCU连上一个已有wifi。推荐使用AP模式
#define SSID_AP             "NodeMCU_WiFi_Car"    // for AP mode
#define PASSWORD_AP         "12345678"            // for AP mode
#define SSID_STA            "your_wifi_ssid"      // for STA mode
#define PASSWORD_STA        "your_wifi_password"  // for STA mode

// motor settings
#define RIGHT_MOTOR_PIN1    4                     // pin 1 of right motor (D2)
#define RIGHT_MOTOR_PIN2    5                     // pin 2 of right motor (D1)
#define LEFT_MOTOR_PIN1     12                    // pin 1 of left motor (D6)
#define LEFT_MOTOR_PIN2     14                    // pin 2 of left motor (D5)
#define MOTOR_SPEED   1200                        // speed for motor

IPAddress local_ip(192, 168, 1, 1); //IP for AP mode
IPAddress gateway(192, 168, 1, 1); //IP for AP mode
IPAddress subnet(255, 255, 255, 0); //IP for AP mode
ESP8266WebServer server(80);
int car_mode = 0; // set car drive mode (0 = stop)

// initialize
void setup() {
  Serial.begin(9600);
  Serial.println("NodeMCU Wifi Car");
  pinMode(RIGHT_MOTOR_PIN1, OUTPUT);
  pinMode(RIGHT_MOTOR_PIN2, OUTPUT);
  pinMode(LEFT_MOTOR_PIN1, OUTPUT);
  pinMode(LEFT_MOTOR_PIN2, OUTPUT);
  car_control(); // stop the car

  if (WIFI_MODE == 1) { // AP mode
    WiFi.softAP(SSID_AP, PASSWORD_AP);
    WiFi.softAPConfig(local_ip, gateway, subnet);
  } else { // STA mode
    WiFi.begin(SSID_STA, PASSWORD_STA);
    Serial.print("Connecting to WiFi...");
    while (WiFi.status() != WL_CONNECTED) {
      delay(100);
      Serial.print(".");
    }
    Serial.println("");
    Serial.print("Connected! IP: ");
    Serial.println(WiFi.localIP()); //the IP is needed for connection in STA mode
  }

  // setup web server to handle specific HTTP requests
  server.on("/", HTTP_GET, handle_OnConnect);
  server.on("/forward", HTTP_GET, handle_forward);
  server.on("/backward", HTTP_GET, handle_backward);
  server.on("/left", HTTP_GET, handle_left);
  server.on("/right", HTTP_GET, handle_right);
  server.on("/stop", HTTP_GET, handle_stop);
  server.onNotFound(handle_NotFound);

  //start server
  server.begin();
  Serial.println("NodeMCU web server started.");
}

// handle HTTP requests and control car
void loop() { 
  server.handleClient();
  car_control();
}

// HTTP request: on connect
void handle_OnConnect() {
  car_mode = 0;
  Serial.println("Client connected");
  server.send(200, "text/html", SendHTML());
}

// HTTP request: stop car
void handle_stop() {
  car_mode = 0;
  Serial.println("Stopped");
  server.send(200, "text/html", SendHTML());
}

// HTTP request: go forward
void handle_forward() {
  car_mode = 1;
  Serial.println("Go forward...");
  server.send(200, "text/html", SendHTML());
}

// HTTP request: go backward
void handle_backward() {
  car_mode = 2;
  Serial.println("Go backward...");
  server.send(200, "text/html", SendHTML());
}

// HTTP request: turn left
void handle_left() {
  car_mode = 3;
  Serial.println("Turn left...");
  server.send(200, "text/html", SendHTML());
}

// HTTP request: turn right
void handle_right() {
  car_mode = 4;
  Serial.println("Turn right...");
  server.send(200, "text/html", SendHTML());
}

// HTTP request: other
void handle_NotFound() {
  car_mode = 0;
  Serial.println("Page error");
  server.send(404, "text/plain", "Not found");
}

// control car movement
void car_control() {
  switch (car_mode) {
    case 0: // stop car
      digitalWrite(RIGHT_MOTOR_PIN1, LOW);
      digitalWrite(RIGHT_MOTOR_PIN2, LOW);
      digitalWrite(LEFT_MOTOR_PIN1, LOW);
      digitalWrite(LEFT_MOTOR_PIN2, LOW);
      break;
    case 1: // go forward
      analogWrite(RIGHT_MOTOR_PIN1, MOTOR_SPEED);
      digitalWrite(RIGHT_MOTOR_PIN2, LOW);
      analogWrite(LEFT_MOTOR_PIN1, MOTOR_SPEED);
      digitalWrite(LEFT_MOTOR_PIN2, LOW);
      break;
    case 2: // go backward
      digitalWrite(RIGHT_MOTOR_PIN1, LOW);
      analogWrite(RIGHT_MOTOR_PIN2, MOTOR_SPEED);
      digitalWrite(LEFT_MOTOR_PIN1, LOW);
      analogWrite(LEFT_MOTOR_PIN2, MOTOR_SPEED);
      break;
    case 3: // turn left
      analogWrite(RIGHT_MOTOR_PIN1, MOTOR_SPEED);
      digitalWrite(RIGHT_MOTOR_PIN2, LOW);
      digitalWrite(LEFT_MOTOR_PIN1, LOW);
      analogWrite(LEFT_MOTOR_PIN2, MOTOR_SPEED);
      break;
    case 4: // turn right
      digitalWrite(RIGHT_MOTOR_PIN1, LOW);
      analogWrite(RIGHT_MOTOR_PIN2, MOTOR_SPEED);
      analogWrite(LEFT_MOTOR_PIN1, MOTOR_SPEED);
      digitalWrite(LEFT_MOTOR_PIN2, LOW);

  }
}

// output HTML web page for user
String SendHTML() {
  String html = "<!DOCTYPE html>\n"
  "<html>\n"
  "<head>\n"
  "<title>NodeMCU Wifi Car by OrangeZero</title>\n"
  "<meta name=\"viewport\" content=\"width=device-width, initial-scale=1\">\n"
  "</head>\n"
  "<body>\n"
  "<div align=\"center\">\n"
  "<h1>NodeMCU Wifi Car by OrangeZero</h1>\n"
  "<br>\n"
  "<form method=\"GET\">\n"
  "<input type=\"button\" value=\"Go forward\" onclick=\"window.location.href='/forward'\">\n"
  "<br><br>\n"
  "<input type=\"button\" value=\"Go backward\" onclick=\"window.location.href='/backward'\">\n"
  "<br><br>\n"
  "<input type=\"button\" value=\"Turn left\" onclick=\"window.location.href='/left'\">\n"
  "<br><br>\n"
  "<input type=\"button\" value=\"Turn right\" onclick=\"window.location.href='/right'\">\n"
  "<br><br>\n"
  "<input type=\"button\" value=\"Car stop\" onclick=\"window.location.href='/stop'\">\n"
  "</form>\n"
  "</div>\n"
  "<a href='https://profile.zjurl.cn/rogue/ugc/profile/?user_id=4182130004597211'>Copyright 2020 OrangeZero</a>"
  "</body>\n"
  "</html>\n";
  return html;
}

点击上传按钮，稍等片刻，等待上传完成：

四、开动小车！

到这里我们的小车就制作完成了！让我们来发动小车吧~

在打开移动电源的开关，连接好电池盒的正负极之后，稍等片刻，我们就可以搜索到wifi信号：

NodeMCU WiFi Car

手机连接wifi之后，在浏览器中打开：192.168.1.1

点击相关按钮就可以操纵小车前进，后退，转向，还有停止了~

大家有没有觉得并没有那么难，而且成就感满满的呢~

大家有什么还有什么想要做的物联网或者智能家居项目呢？在下面留言告诉我吧~

我是零度橙子，装机爱好者，科技达人，谷歌认证云计算架构师，大家可以关注我，了解有用有趣的科技知识～