udp_test.ino

#include <ESP8266WiFi.h>
#include <WiFiUDP.h>

WiFiUDP UDP;


const char* ssid = "sensorNode";
const char* password = "1234567890";
boolean wifiConnected = false;

IPAddress ip = {192,168,0,255};

// UDP variables
unsigned int localPort = 8888;
boolean udpConnected = false;

void setup() {
    // Initialise Serial connection
    Serial.begin(115200);
    
    // Initialise wifi connection
    wifiConnected = connectWifi();

    // only proceed if wifi connection successful
    if(wifiConnected){
        udpConnected = connectUDP();
        if (udpConnected){
          // initialise pins
          pinMode(5,OUTPUT);
        }
    }
}

void loop() {
    // check if the WiFi and UDP connections were successful
    if(wifiConnected){
    if(udpConnected){
    
   
      UDP.beginPacket(ip, 8888);    
      UDP.write("Hello");
      UDP.endPacket();
    
    }
    }

    delay(500);

}

// connect to UDP – returns true if successful or false if not
boolean connectUDP(){
    boolean state = false;
    
    Serial.println("");
    Serial.println("Connecting to UDP");
    
    if(UDP.begin(localPort) == 1){
      Serial.println("Connection successful");
      state = true;
    }
    else{
    Serial.println("Connection failed");
    }
    
    return state;
}

// connect to wifi – returns true if successful or false if not
boolean connectWifi(){
    boolean state = true;
    int i = 0;
    WiFi.begin(ssid, password);
    Serial.println("");
    Serial.println("Connecting to WiFi");
    
    // Wait for connection
    Serial.print("Connecting");
    while (WiFi.status() != WL_CONNECTED) {
      delay(500);
      Serial.print(".");
      if (i > 10){
      state = false;
      break;
    }
    i++;
    }
    if (state){
      Serial.println("");
      Serial.print("Connected to ");
      Serial.println(ssid);
      Serial.print("IP address: ");
      Serial.println(WiFi.localIP());
    }
    else {
      Serial.println("");
      Serial.println("Connection failed.");
    }
    return state;
}