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？
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~
将以下代码复制到Arduino IDE:
<code>// 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 = "\\n"
"\\n"
"\\n"
"<title>NodeMCU Wifi Car by OrangeZero/<title>\\n"
"\\n"
"\\n"
"\\n"
"
"
NodeMCU Wifi Car by OrangeZero
\\n""
\\n"
"\\n"
"
" "
"\\n"
"\\n";
return html;
}/<esp8266webserver.h>/<esp8266wifi.h>/<code>
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～