// Can be included as many times as necessary, without `Multiple Definitions` Linker Error
#include "AsyncUDP_RP2040W.hpp"         //https://github.com/khoih-prog/AsyncUDP_RP2040W

// To be included only in main(), .ino with setup() to avoid `Multiple Definitions` Linker Error
#include "AsyncUDP_RP2040W.h"           //https://github.com/khoih-prog/AsyncUDP_RP2040W

#include "defines.h"
#include <time.h>

// To be included only in main(), .ino with setup() to avoid `Multiple Definitions` Linker Error
#include <AsyncUDP_RP2040W.h>         // https://github.com/khoih-prog/AsyncUDP_RP2040W

// 0.ca.pool.ntp.org
IPAddress timeServerIP = IPAddress(208, 81, 1, 244);
// time.nist.gov
//IPAddress timeServerIP = IPAddress(132, 163, 96, 1);

#define NTP_REQUEST_PORT      123

//char timeServer[] = "time.nist.gov";  // NTP server
char timeServer[] = "0.ca.pool.ntp.org";

const int NTP_PACKET_SIZE = 48;       // NTP timestamp is in the first 48 bytes of the message

byte packetBuffer[NTP_PACKET_SIZE];   // buffer to hold incoming and outgoing packets

// A UDP instance to let us send and receive packets over UDP
AsyncUDP Udp;

int status = WL_IDLE_STATUS;

// send an NTP request to the time server at the given address
void createNTPpacket()
{
  Serial.println("============= createNTPpacket =============");

  // set all bytes in the buffer to 0
  memset(packetBuffer, 0, NTP_PACKET_SIZE);
  // Initialize values needed to form NTP request
  // (see URL above for details on the packets)

  packetBuffer[0]   = 0b11100011;   // LI, Version, Mode
  packetBuffer[1]   = 0;     // Stratum, or type of clock
  packetBuffer[2]   = 6;     // Polling Interval
  packetBuffer[3]   = 0xEC;  // Peer Clock Precision
  
  // 8 bytes of zero for Root Delay & Root Dispersion
  packetBuffer[12]  = 49;
  packetBuffer[13]  = 0x4E;
  packetBuffer[14]  = 49;
  packetBuffer[15]  = 52;
}

void parsePacket(AsyncUDPPacket packet)
{
  ...
}

void sendNTPPacket()
{
  createNTPpacket();

  Serial.println("Sending UDP Packet");
  
  //Send unicast
  Udp.write(packetBuffer, sizeof(packetBuffer));

  Serial.println("Sent UDP Packet");
}

void printWifiStatus()
{
  ...
}

void setup()
{
  Serial.begin(115200);
  while (!Serial && millis() < 5000);

  Serial.print("\nStart AsyncUdpNTPClient on "); Serial.println(BOARD_NAME);
  Serial.println(ASYNC_UDP_RP2040W_VERSION);
  
  ///////////////////////////////////
  
  // check for the WiFi module:
  if (WiFi.status() == WL_NO_MODULE)
  {
    Serial.println("Communication with WiFi module failed!");
    // don't continue
    while (true);
  }

  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();

  ///////////////////////////////////

  //NTP requests are to port NTP_REQUEST_PORT = 123
  if (Udp.connect(timeServerIP, NTP_REQUEST_PORT))
  {
    Serial.println("UDP connected");

    Udp.onPacket([](AsyncUDPPacket packet)
    {
      parsePacket(packet);
    });
  }
}

void loop()
{
  sendNTPPacket();

  // wait 60 seconds before asking for the time again
  delay(60000);
}

Start AsyncUdpNTPClient on RASPBERRY_PI_PICO_W
AsyncUDP_RP2040W v1.0.0
Connecting to SSID: HueNet1
SSID: HueNet1
Local IP Address: 192.168.2.87
signal strength (RSSI):-25 dBm
UDP connected
============= createNTPpacket =============
Sending UDP Packet
Sent UDP Packet
Received UDP Packet Type: Unicast
From: 208.81.1.244:123, To: 192.168.2.87:58997, Length: 48
Seconds since Jan 1 1900 = 3842738319
Epoch/Unix time = 1633749519
The UTC/GMT time is Sat 2021-10-09 03:18:39 GMT
============= createNTPpacket =============
Sending UDP Packet
Sent UDP Packet
Received UDP Packet Type: Unicast
From: 208.81.1.244:123, To: 192.168.2.87:58997, Length: 48
Seconds since Jan 1 1900 = 3842738378
Epoch/Unix time = 1633749578
The UTC/GMT time is Sat 2021-10-09 03:19:38 GMT

Start AsyncUDPServer on RASPBERRY_PI_PICO_W
AsyncUDP_RP2040W v1.0.0
Connecting to SSID: HueNet1
SSID: HueNet1
Local IP Address: 192.168.2.87
signal strength (RSSI):-25 dBm
UDP Listening on IP: 192.168.2.87
UDP Packet Type: Unicast, From: 192.168.2.30:33380, To: 192.168.2.87:1234, Length: 27, Data: Hello, RASPBERRY_PI_PICO_W!

Start AsyncUDPMulticastServer on RASPBERRY_PI_PICO_W
AsyncUDP_RP2040W v1.0.0
Connecting to SSID: HueNet1
SSID: HueNet1
Local IP Address: 192.168.2.87
signal strength (RSSI):-25 dBm
UDP Listening on IP: 192.168.2.87
UDP Packet Type: Unicast, From: 192.168.2.30:50119, To: 192.168.2.87:1234, Length: 27, Data: Hello, RASPBERRY_PI_PICO_W!

#define AUDP_RP2040W_DEBUG_PORT      Serial

// Use from 0 to 4. Higher number, more debugging messages and memory usage.
#define _AUDP_RP2040W_LOGLEVEL_      0

#define AUDP_RP2040W_DEBUG_PORT      Serial

// Use from 0 to 4. Higher number, more debugging messages and memory usage.
#define _AUDP_RP2040W_LOGLEVEL_      4