Soccer Robot Tutorial
Description：
Can you imagine that a robot can play soccer? This idea has became realistic. As we know, the RoboCup championship is generally held each year. In this part, we will create a soccer robot to play soccer.
Install APP
⚠️Special note: If you have downloaded and installed the APP, this step is skipped; If not, please refer to the installation instructions of link: Project 18：Read WiFi APP Button String .
How to install the soccer robot
Step 1
Remove two photoresistors
Required Parts
Install
Complete
Step 2
Required Parts
Install
Complete
Step 3
Required Parts
Install
Complete
Step 4
Required Parts
Install
Complete
Step 5
Required Parts
Install
Complete
Step 6
Required Parts
Install
Note the installation direction of the part marked by the circle
Complete
Step 7
Required Parts
Install
Complete
Step 8
Required Parts
Install
Adjust the angle of the claw. Then make it close and face front
Complete
Step 9
Required Parts
Set the angle of the servo to 180 degree
Wire Up Servo |
PCB Board |
|---|---|
Brown |
G |
Red |
5V |
Orange |
S2（GPIO23) |
Method 1：Arduino code
Upload the code of the servo to the main board of the Beetlebot car, as shown below
//*************************************************************************************
#include <Arduino.h>
#include <ESP32Servo.h>
Servo myservo; // create servo object to control a servo
int servoPin = 23; // Servo motor pin
void setup() {
myservo.setPeriodHertz(50); // standard 50 hz servo
myservo.attach(servoPin, 500, 2500); // attaches the servo on servoPin to the servo object
myservo.write(180); // the angle of the steering gear is 180°.
delay(1000);
myservo.write(90); // the angle of the steering gear is 90°.
delay(1000);
myservo.write(180); // the angle of the steering gear is 180°.
delay(1000);
}
void loop() {
}
//*************************************************************************************
How to get it ?
In folder …\Codes\Soccer_Robot_Code\270° Servo Angle initialization , open file 270_Servo_Angle_initialization.ino , or copy and paste the above test code into the Arduino IDE.
Method 2：KidsBlock(Scratch) code
You can also initialize the angle of the servo through the following code
Open file 270°_Servo_Angle_initialization.sb3 with KidsBlock IDE, in folder …\Codes\Soccer_Robot_Code\270° Servo Angle initialization.
Install
Note: Keep the claw close and face front before installing the gear
Complete
Step 10
Required Parts
Install
Complete
Step 11
Required Parts
Install
Complete
Wiring Diagram
Wire up the LEGO servo
Install a soccer goal
Step 1
Required Parts
Install
Complete
Step 2
Required Parts
Install
Complete
Step 3
Required Parts
Install
Complete
Then the soccer goal is installed well.
Test Code for Arduino
⚠️ATTENTION: Before uploading code, please replace the WiFi name(REPLACE_WITH_YOUR_SSID) in the code and the passwords(REPLACE_WITH_YOUR_PASSWORD) into yours.
#include <WiFi.h>
#include <ESPmDNS.h>
#include <WiFiClient.h>
#include <ESP32Servo.h>
//motor
#define left_ctrl 33 //define direction control pins of the left motor as gpio33
#define left_pwm 26 //define PWM control pins of the left motor as gpio26.
#define right_ctrl 32 //define direction control pins of the right motor as gpio32.
#define right_pwm 25 //define PWM control pins of the right motor as gpio25
/*REPLACE WITH YOUR NETWORK CREDENTIALS(Put your SSID & Password)*/
const char* ssid = "REPLACE_WITH_YOUR_SSID"; //Enter SSID here
const char* password = "REPLACE_WITH_YOUR_PASSWORD"; //Enter Password here
// TCP server at port 80 will respond to HTTP requests
WiFiServer server(80);
//servo
const int servoPin = 23;//set the pin of the servo to gpio23.
Servo myservo; // create servo object to control a servo
void setup(void)
{
Serial.begin(115200);
pinMode(left_ctrl,OUTPUT); //set control pins of the left motor to OUTPUT
ledcAttach(left_pwm, 1200, 8); //Set the frequency of left_pwm pin to 1200, PWM resolution to 8 that duty cycle is 256.
pinMode(right_ctrl,OUTPUT);//set direction control pins of the right motor to OUTPUT..
ledcAttach(right_pwm, 1200, 8); //Set the frequency of right_pwm pin to 1200, PWM resolution to 8 that duty cycle is 256.
myservo.setPeriodHertz(50); // standard 50 hz servo
myservo.attach(servoPin, 500, 2500); // attaches the servo on servoPin to the servo object.
myservo.write(180); // the initial angle of the servo is set to 180° .
delay(300);
// Connect to WiFi network
WiFi.begin(ssid, password);
Serial.println("");
// Wait for connection
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("");
Serial.print("Connected to ");
Serial.println(ssid);
Serial.print("IP address: ");
Serial.println(WiFi.localIP());
// Set up mDNS responder:
// - first argument is the domain name, in this example
// the fully-qualified domain name is "esp32.local"
// - second argument is the IP address to advertise
// we send our IP address on the WiFi network
if (!MDNS.begin("esp32")) {
Serial.println("Error setting up MDNS responder!");
while(1) {
delay(1000);
}
}
Serial.println("mDNS responder started");
// Start TCP (HTTP) server
server.begin();
Serial.println("TCP server started");
// Add service to MDNS-SD
MDNS.addService("http", "tcp", 80);
}
void loop(void)
{
// Check if a client has connected
WiFiClient client = server.available();
if (!client) {
return;
}
//Serial.println("");
//Serial.println("New client");
// Wait for data from client to become available
while(client.connected() && !client.available()){
delay(1);
}
// Read the first line of HTTP request
String req = client.readStringUntil('\r');
//Serial.println(req);
// First line of HTTP request looks like "GET /path HTTP/1.1"
// Retrieve the "/path" part by finding the spaces
int addr_start = req.indexOf(' ');
int addr_end = req.indexOf(' ', addr_start + 1);
if (addr_start == -1 || addr_end == -1) {
//Serial.print("Invalid request: ");
//Serial.println(req);
return;
}
req = req.substring(addr_start + 1, addr_end);
//Serial.print("Request: ");
Serial.println(req);
String s;
if (req == "/")
{
IPAddress ip = WiFi.localIP();
String ipStr = String(ip[0]) + '.' + String(ip[1]) + '.' + String(ip[2]) + '.' + String(ip[3]);
s = "HTTP/1.1 200 OK\r\nContent-Type: text/html\r\n\r\n<!DOCTYPE HTML>\r\n<html>Hello from ESP32 at ";
s += ipStr;
s += "</html>\r\n\r\n";
Serial.println("Sending 200");
client.println(WiFi.localIP());
}
else if(req == "/btn/F")
{
digitalWrite(left_ctrl,LOW); //set direction control pins of the left motor to LOW.
ledcWrite(left_pwm, 150); //the left motor outputs PWM 150
digitalWrite(right_ctrl,LOW); //set control pins of the right motor to LOW.
ledcWrite(right_pwm, 150); //the right motor outputs PWM 150
}
else if(req == "/btn/B")
{
digitalWrite(left_ctrl, HIGH);
ledcWrite(left_pwm, 150);
digitalWrite(right_ctrl, HIGH);
ledcWrite(right_pwm, 150);
}
else if(req == "/btn/L")
{
digitalWrite(left_ctrl,HIGH);
ledcWrite(left_pwm, 150);
digitalWrite(right_ctrl,LOW);
ledcWrite(right_pwm, 150);
}
else if(req == "/btn/R")
{
digitalWrite(left_ctrl,LOW);
ledcWrite(left_pwm, 150);
digitalWrite(right_ctrl,HIGH);
ledcWrite(right_pwm, 150);
}
else if(req == "/btn/S")
{
digitalWrite(left_ctrl,LOW);
ledcWrite(left_pwm, 0);
digitalWrite(right_ctrl,LOW);
ledcWrite(right_pwm, 0);
}
else if(req == "/btn/p")
{
Serial.write('p');
myservo.write(180);
delay(200);
}
else if(req == "/btn/q")
{
Serial.write('q');
client.println("q");
}
else if(req == "/btn/x")
{
myservo.write(160);
delay(200);
}
}
Test Code for Kidsblock
Build up the soccer goal with building blocks and place it at fixed location, connect the robot car through Wifi.
Put a small soccer in the middle of the claw of the robot car, press and hold down the button 
to enable the claw to hold the soccer, then press buttons 
to adjust the car’s movement direction , so as to put the soccer close to the soccer goal. At last, release the button to allow the soccer to drop on the floor and roll to the soccer goal. If not, repeat the above step to shoot the goal.
If your friend owns this kind of soccer robot, you guys can hold a soccer match. It sounds amazing, right?.