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@peterbmarks
Created Sep 7, 2021
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WSPR Beacon using Si5351 oscillator and NTP client for time sync
/*
* Very simple WSPR beacon using NTP for time synchronisation and an Si5351 oscillator.
* Created on a WeMos D1 R2 (ESP8266 on Arduino style board).
* Peter Marks VK3TPM
*
* Heavily based on work by Jason Milgram & Michael Margolis
*/
/*
Udp NTP Client
Get the time from a Network Time Protocol (NTP) time server
Demonstrates use of UDP sendPacket and ReceivePacket
For more on NTP time servers and the messages needed to communicate with them,
see http://en.wikipedia.org/wiki/Network_Time_Protocol
created 4 Sep 2010
by Michael Margolis
modified 9 Apr 2012
by Tom Igoe
updated for the ESP8266 12 Apr 2015
by Ivan Grokhotkov
This code is in the public domain.
*/
#include <ESP8266WiFi.h>
#include <WiFiUdp.h>
#include <si5351.h>
#include <JTEncode.h>
#include "Wire.h"
#ifndef STASSID
#define STASSID "NETWORKNAME"
#define STAPSK "NETPASSWORD"
#endif
const char * ssid = STASSID; // your network SSID (name)
const char * pass = STAPSK; // your network password
unsigned int localPort = 2390; // local port to listen for UDP packets
/* Don't hardwire the IP address or we won't get the benefits of the pool.
Lookup the IP address for the host name instead */
//IPAddress timeServer(129, 6, 15, 28); // time.nist.gov NTP server
IPAddress timeServerIP; // time.nist.gov NTP server address
const char* ntpServerName = "time.nist.gov";
const int NTP_PACKET_SIZE = 48; // NTP time stamp is in the first 48 bytes of the message
byte packetBuffer[ NTP_PACKET_SIZE]; //buffer to hold incoming and outgoing packets
#define TONE_SPACING 146 // ~1.46 Hz
#define WSPR_CTC 10672 // CTC value for WSPR
#define SYMBOL_COUNT WSPR_SYMBOL_COUNT
#define CORRECTION 0 // Change this for your ref osc
Si5351 si5351;
JTEncode jtencode;
unsigned long freq = 7038600UL + 1500UL; // Change this
char call[7] = "VK0ABC"; // Change this
char loc[5] = "QF22"; // Change this
uint8_t dbm = 10;
uint8_t tx_buffer[SYMBOL_COUNT];
void setupSi5351() {
// Initialize the Si5351
// Change the 2nd parameter in init if using a ref osc other
// than 25 MHz
bool i2c_found = si5351.init(SI5351_CRYSTAL_LOAD_8PF, 0, CORRECTION);
if(i2c_found == true) {
Serial.println("i2c found!");
// Set CLK0 output
si5351.set_freq(freq * 100, SI5351_CLK0);
si5351.drive_strength(SI5351_CLK0, SI5351_DRIVE_8MA); // Set for max power
si5351.set_clock_pwr(SI5351_CLK0, 0); // Disable the clock initially
} else {
Serial.println("i2c NOT found!");
}
}
// Loop through the string, transmitting one character at a time.
void transmitWSPR()
{
uint8_t i;
jtencode.wspr_encode(call, loc, dbm, tx_buffer);
// Reset the tone to 0 and turn on the output
si5351.set_clock_pwr(SI5351_CLK0, 1);
digitalWrite(LED_BUILTIN, HIGH);
// Now do the rest of the message
for(i = 0; i < SYMBOL_COUNT; i++)
{
//Serial.print("|");
si5351.set_freq((freq * 100) + (tx_buffer[i] * TONE_SPACING), SI5351_CLK0);
delay(683);
}
Serial.println();
// Turn off the output
si5351.set_clock_pwr(SI5351_CLK0, 0);
digitalWrite(LED_BUILTIN, LOW);
}
// A UDP instance to let us send and receive packets over UDP
WiFiUDP udp;
void setup() {
Serial.begin(115200);
Serial.println();
Serial.println();
Serial.println();
setupSi5351();
// We start by connecting to a WiFi network
Serial.print("Connecting to ");
Serial.println(ssid);
WiFi.mode(WIFI_STA);
WiFi.begin(ssid, pass);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("");
Serial.println("WiFi connected");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
Serial.println("Starting UDP");
udp.begin(localPort);
Serial.print("Local port: ");
Serial.println(udp.localPort());
}
void loop() {
//get a random server from the pool
WiFi.hostByName(ntpServerName, timeServerIP);
sendNTPpacket(timeServerIP); // send an NTP packet to a time server
// wait to see if a reply is available
delay(1000);
int cb = udp.parsePacket();
if (!cb) {
Serial.println("no packet yet");
} else {
Serial.print("packet received, length=");
Serial.println(cb);
// We've received a packet, read the data from it
udp.read(packetBuffer, NTP_PACKET_SIZE); // read the packet into the buffer
//the timestamp starts at byte 40 of the received packet and is four bytes,
// or two words, long. First, esxtract the two words:
unsigned long highWord = word(packetBuffer[40], packetBuffer[41]);
unsigned long lowWord = word(packetBuffer[42], packetBuffer[43]);
// combine the four bytes (two words) into a long integer
// this is NTP time (seconds since Jan 1 1900):
unsigned long secsSince1900 = highWord << 16 | lowWord;
Serial.print("Seconds since Jan 1 1900 = ");
Serial.println(secsSince1900);
// now convert NTP time into everyday time:
Serial.print("Unix time = ");
// Unix time starts on Jan 1 1970. In seconds, that's 2208988800:
const unsigned long seventyYears = 2208988800UL;
// subtract seventy years:
unsigned long epoch = secsSince1900 - seventyYears;
// print Unix time:
Serial.println(epoch);
// print the hour, minute and second:
Serial.print("The UTC time is "); // UTC is the time at Greenwich Meridian (GMT)
Serial.print((epoch % 86400L) / 3600); // print the hour (86400 equals secs per day)
Serial.print(':');
if (((epoch % 3600) / 60) < 10) {
// In the first 10 minutes of each hour, we'll want a leading '0'
Serial.print('0');
}
int minute = (epoch % 3600) / 60;
Serial.print(minute); // print the minute (3600 equals secs per minute)
Serial.print(':');
int second = epoch % 60;
if (second < 10) {
// In the first 10 seconds of each minute, we'll want a leading '0'
Serial.print('0');
}
Serial.println(second); // print the second
// calculate time to wait before next 2 minute slot
int minutesToWait = ((minute + 1) % 2);
Serial.print("minutesToWait = ");
Serial.println(minutesToWait);
int secondsToWait = (minutesToWait * 60) + (60 - second);
Serial.print("secondsToWait = ");
Serial.println(secondsToWait);
delay(secondsToWait * 1000);
Serial.println("WSPR TX start");
transmitWSPR();
Serial.println("WSPR TX ends");
}
// wait ten seconds before asking for the time again
delay(10000);
}
// send an NTP request to the time server at the given address
void sendNTPpacket(IPAddress& address) {
Serial.println("sending NTP packet...");
// 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;
// all NTP fields have been given values, now
// you can send a packet requesting a timestamp:
udp.beginPacket(address, 123); //NTP requests are to port 123
udp.write(packetBuffer, NTP_PACKET_SIZE);
udp.endPacket();
}
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