UdpSendReceive.ino

/****************************************************************************************************************************
  UDPSendReceive.ino - Simple Arduino web server sample for SAMD21 running WiFiNINA shield
  For any WiFi shields, such as WiFiNINA W101, W102, W13x, or custom, such as ESP8266/ESP32-AT, Ethernet, etc

  WiFiWebServer is a library for the ESP32-based WiFi shields to run WebServer
  Based on and modified from ESP8266 https://github.com/esp8266/Arduino/releases
  Based on  and modified from Arduino WiFiNINA library https://www.arduino.cc/en/Reference/WiFiNINA
  Built by Khoi Hoang https://github.com/khoih-prog/WiFiWebServer
  Licensed under MIT license
 ***************************************************************************************************************************************/

#include "defines.h"

#define DEBUG_WIFI_WEBSERVER_PORT   Serial

int status = WL_IDLE_STATUS;     // the Wifi radio's status

unsigned int localPort = 1883;    //10002;  // local port to listen on

char packetBuffer[255];          // buffer to hold incoming packet
char ReplyBuffer[] = "ACK";      // a string to send back

WiFiUDP Udp;

void printWifiStatus()
{
  // print the SSID of the network you're attached to:
  // you're connected now, so print out the data
  Serial.print(F("You're connected to the network, IP = "));
  Serial.println(WiFi.localIP());

  Serial.print(F("SSID: "));
  Serial.print(WiFi.SSID());

  // print the received signal strength:
  long rssi = WiFi.RSSI();
  Serial.print(F(", Signal strength (RSSI):"));
  Serial.print(rssi);
  Serial.println(F(" dBm"));
}

void setup()
{
  Serial.begin(115200);

  while (!Serial && millis() < 5000);

  Serial.print(F("\nStarting UDPSendReceive on "));
  Serial.print(BOARD_NAME);
  Serial.print(F(" with "));
  Serial.println(SHIELD_TYPE);
  Serial.println(WIFI_WEBSERVER_VERSION);

#if WIFI_USING_ESP_AT

  // initialize serial for ESP module
  EspSerial.begin(115200);
  // initialize ESP module
  WiFi.init(&EspSerial);

  Serial.println(F("WiFi shield init done"));

#endif

#if !(ESP32 || ESP8266)

  // check for the presence of the shield
#if USE_WIFI_NINA

  if (WiFi.status() == WL_NO_MODULE)
#else
  if (WiFi.status() == WL_NO_SHIELD)
#endif
  {
    Serial.println(F("WiFi shield not present"));

    // don't continue
    while (true);
  }

#if USE_WIFI_NINA
  String fv = WiFi.firmwareVersion();

  if (fv < WIFI_FIRMWARE_LATEST_VERSION)
  {
    Serial.println(F("Please upgrade the firmware"));
  }

#endif

#endif

  Serial.print(F("Connecting to SSID: "));
  Serial.println(ssid);

  status = WiFi.begin(ssid, pass);

  delay(1000);

  // attempt to connect to WiFi network
  while ( status != WL_CONNECTED)
  {
    delay(500);

    // Connect to WPA/WPA2 network
    status = WiFi.status();
  }

  printWifiStatus();

  Serial.println(F("\nStarting connection to server..."));
  // if you get a connection, report back via serial:
  Udp.begin(localPort);

  Serial.print(F("Listening on port "));
  Serial.println(localPort);
}

void loop()
{
  // if there's data available, read a packet
  int packetSize = Udp.parsePacket();

  if (packetSize)
  {
    Serial.print(F("Received packet of size "));
    Serial.println(packetSize);
    Serial.print(F("From "));
    IPAddress remoteIp = Udp.remoteIP();
    Serial.print(remoteIp);
    Serial.print(F(", port "));
    Serial.println(Udp.remotePort());

    // read the packet into packetBufffer
    int len = Udp.read(packetBuffer, 255);

    if (len > 0)
    {
      packetBuffer[len] = 0;
    }

    Serial.println(F("Contents:"));
    Serial.println(packetBuffer);

    // send a reply, to the IP address and port that sent us the packet we received
    Udp.beginPacket(Udp.remoteIP(), Udp.remotePort());

#if (ESP32 || ESP8266)
    Udp.write((uint8_t *) ReplyBuffer, sizeof(ReplyBuffer));
#else
    Udp.write(ReplyBuffer);
#endif

    Udp.endPacket();
  }
}