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@SeanOC SeanOC/countown_clock.ino
Last active Apr 17, 2017

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/*
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 <Adafruit_GFX.h>
#include "Adafruit_LEDBackpack.h"
Adafruit_7segment matrix = Adafruit_7segment();
char ssid[] = "chaunceysnewhotness2.4"; // your network SSID (name)
char pass[] = "bitly<3chauncey"; // 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
// A UDP instance to let us send and receive packets over UDP
WiFiUDP udp;
unsigned long counter;
void setup()
{
Serial.begin(115200);
Serial.println();
Serial.println();
// We start by connecting to a WiFi network
Serial.print("Connecting to ");
Serial.println(ssid);
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());
// 7 Segement Setup
#ifndef __AVR_ATtiny85__
Serial.println("7 Segment Backpack present");
#endif
matrix.begin(0x70);
counter = 0;
}
void loop()
{
//get a random server from the pool
WiFi.hostByName(ntpServerName, timeServerIP);
if (counter % 10 == 0) {
counter = 0;
sendNTPpacket(timeServerIP); // send an NTP packet to a time server
// wait to see if a reply is available
delay(1000);
blinkColon(counter);
unsigned int hour = 0;
unsigned int minute = 0;
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);
hour = (epoch % 86400L) / 3600;
minute = (epoch % 3600) / 60;
// print the hour, minute and second:
Serial.print("The UTC time is "); // UTC is the time at Greenwich Meridian (GMT)
Serial.print(hour); // 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');
}
Serial.print(minute); // print the minute (3600 equals secs per minute)
Serial.print(':');
if ( (epoch % 60) < 10 ) {
// In the first 10 seconds of each minute, we'll want a leading '0'
Serial.print('0');
}
Serial.println(epoch % 60); // print the second
if (hour == 23 && minute == 60) {
for (uint16_t counter = 0; counter < 60; counter++) {
if (counter % 2 == 0) {
matrix.writeDigitNum(0, 0);
matrix.writeDigitNum(1, 0);
matrix.writeDigitNum(2, 0);
matrix.writeDigitNum(3, 0);
matrix.drawColon(true);
} else {
matrix.print(0, DEC);
matrix.drawColon(false);
}
matrix.writeDisplay();
delay(1000);
}
return;
}
if (hour <= 20) {
hour = 20 - hour;
} else {
hour = 44 - hour;
}
minute = 60 - minute;
uint16_t displayNum = (hour * 100) + minute;
matrix.print(displayNum, DEC);
if (displayNum < 1000) {
matrix.writeDigitNum(0, 0);
}
if (displayNum < 100) {
matrix.writeDigitNum(1, 0);
}
if (displayNum < 10) {
matrix.writeDigitNum(2, 0);
}
matrix.writeDisplay();
}
}
delay(1000);
blinkColon(counter);
}
// send an NTP request to the time server at the given address
unsigned long 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();
}
void blinkColon(unsigned long& counter)
{
counter++;
if (counter % 2 == 0) {
matrix.drawColon(false);
} else {
matrix.drawColon(true);
}
matrix.writeDisplay();
Serial.print("Counter: ");
Serial.println(counter);
}
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