Setting up UDP on ESP32

Projects Networking, Protocols, and Devices
1

Hello,

This is my first time with wireless networking so I'm sure I'm doing something dumb, but I have been banging my head against the wall all week and can't seem to get this up and running.

I am doing a project for someone who needs to use the ESP32 Thing to have a sensor (measures wind velocity) to communicate via OSC to a program called Touch Designer. I got the sensor up and running no problem, and I can run the example wifi sketches (turn the light on and off with browser etc), but when it came to communicating via UDP to the OSClistener, it just...doesn't do it.

So I tried communicating via UDP alone - I downloaded UDP sender/receiver and ran the WiFi UDP client example:

/*
 *  This sketch sends random data over UDP on a ESP32 device
 *
 */
#include <WiFi.h>
#include <WiFiUdp.h>

// WiFi network name and password:
const char * networkName = "asdfasdfas";
const char * networkPswd = "asdfadsfasdf";

//IP address to send UDP data to:
// either use the ip address of the server or 
// a network broadcast address
const char * udpAddress = "192.168.1.100";
const int udpPort = 3333;

//Are we currently connected?
boolean connected = false;

//The udp library class
WiFiUDP udp;

void setup(){
  // Initilize hardware serial:
  Serial.begin(115200);
  
  //Connect to the WiFi network
  connectToWiFi(networkName, networkPswd);
}

void loop(){
  //only send data when connected
  if(connected){
    //Send a packet
    udp.beginPacket(udpAddress,udpPort);
    udp.printf("Seconds since boot: %u", millis()/1000);
    udp.endPacket();
  }
  //Wait for 1 second
  delay(1000);
}

void connectToWiFi(const char * ssid, const char * pwd){
  Serial.println("Connecting to WiFi network: " + String(ssid));

  // delete old config
  WiFi.disconnect(true);
  //register event handler
  WiFi.onEvent(WiFiEvent);
  
  //Initiate connection
  WiFi.begin(ssid, pwd);

  Serial.println("Waiting for WIFI connection...");
}

//wifi event handler
void WiFiEvent(WiFiEvent_t event){
    switch(event) {
      case SYSTEM_EVENT_STA_GOT_IP:
          //When connected set 
          Serial.print("WiFi connected! IP address: ");
          Serial.println(WiFi.localIP());  
          //initializes the UDP state
          //This initializes the transfer buffer
          udp.begin(WiFi.localIP(),udpPort);
          connected = true;
          break;
      case SYSTEM_EVENT_STA_DISCONNECTED:
          Serial.println("WiFi lost connection");
          connected = false;
          break;
    }
}

Serial shows I am connecting to WiFi but when I open the UDP receiver, it says it's listening but I don't see the "seconds since boot" message.

ANY advice would be so so appreciated.

2

OK, so now I tried a different example sketch:

#include <WiFi.h>
#include <WiFiUdp.h>

/* WiFi network name and password */
const char * ssid = ".....";
const char * pwd = ".....";

// IP address to send UDP data to.
// it can be ip address of the server or 
// a network broadcast address
// here is broadcast address
const char * udpAddress = "73.180.146.22";
const int udpPort = 3333;

//create UDP instance
WiFiUDP udp;

void setup(){
  Serial.begin(115200);
  
  //Connect to the WiFi network
   WiFi.begin(ssid, pwd);
  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());
  //This initializes udp and transfer buffer
  udp.begin(udpPort);
}

void loop(){
  //data will be sent to server
  uint8_t buffer[50] = "hello world";
  //send hello world to server
  udp.beginPacket(udpAddress, udpPort);
  udp.write(buffer, 11);
  udp.endPacket();
  memset(buffer, 0, 50);
  //processing incoming packet, must be called before reading the buffer
  udp.parsePacket();
  //receive response from server, it will be HELLO WORLD
  if(udp.read(buffer, 50) > 0){
    Serial.print("Server to client: ");
    Serial.println((char *)buffer);
  }
  //Wait for 1 second
  delay(1000);
}

I receive "hello world" message. Perhaps I am communicating, just not reading it right? I still don't see anything trying to monitor the port in Touch Designer or UDP Sender/Receiver

3

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