countown_clock.ino

/*

 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);
}