LCD Clock with NTP time

Tell us the story of your project: 

I got a new Arduino compatible board with WiFi support, and in order to learn how to use it, I made a clock that fetches the time from a NTP network time server, so that I will never need to set the time and it will always be accurate.

How-to: 

In this project I am using the Ameba-1 development board from Realtek, based on the RTL8195/RTL8710 soc, part of its new AmebaIoT ecosystem. This board can be programmed using the Arduino IDE and is pin compatible with many sensors and expansion boards. It has a higher specification compared to regular boards, and has WiFi, NFC, and USB Host functionality as well, making it suitable for IoT applications.

 

First, download and install the Arduino IDE from https://www.arduino.cc/en/Main/Software.

Next, follow the instructions at https://github.com/ambiot/amb1_arduino to install the support package for the board.

Connect the LCD display to the board using jumper wires, as shown in the video.

Copy the following code into the editor, upload to the board and reset. You should see the board connect to the internet and update the time.

 

#include <WiFi.h>
#include <WiFiUdp.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE);
int status = WL_IDLE_STATUS;
char ssid[] = "yourNetwork";  //  your network SSID (name)
char pass[] = "yourPassword";       // your network password
int keyIndex = 0;            // your network key Index number (needed only for WEP)

unsigned int localPort = 2390;      // local port to listen for UDP packets

IPAddress timeServer(129, 6, 15, 28); // time.nist.gov NTP server

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;

int hour = 0;
int minute = 0;
int second = 0;
int timezone = 8;   // change to your local timezone, -6 for US central time

void setup() {
  // Open serial communications and wait for port to open:
  Serial.begin(9600);
  while (!Serial) {
    ; // wait for serial port to connect. Needed for native USB port only
  }
  
  lcd.begin(16,2);
  lcd.backlight();
  lcd.print("Connecting...");

  // attempt to connect to Wifi network:
  while (status != WL_CONNECTED) {
    Serial.print("Attempting to connect to SSID: ");
    Serial.println(ssid);
    // Connect to WPA/WPA2 network. Change this line if using open or WEP network:
    status = WiFi.begin(ssid, pass);

    // wait 10 seconds for connection:
    delay(10000);
  }

  Serial.println("Connected to wifi");
  printWifiStatus();

  Serial.println("\nStarting connection to server...");
  Udp.begin(localPort);
}

void loop() {
  updateTime();
  updateLCD();
  // wait ten seconds before asking for the time again
  delay(10000);
}

void updateLCD()
{
    lcd.clear();
    lcd.print("NTP Time:");
    lcd.setCursor(0, 1);
    hour = hour + timezone;
    if (hour<10)
    {
      lcd.print("0");
    }
    lcd.print(hour);
    lcd.print(" : ");
    if (minute<10)
    {
      lcd.print("0");
    }
    lcd.print(minute);
}

void updateTime ()
{
    sendNTPpacket(timeServer); // send an NTP packet to a time server
  // wait to see if a reply is available
  delay(1000);
  Serial.println(Udp.parsePacket());
  if (Udp.parsePacket()) {
    Serial.println("packet received");
    // 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)
    hour = ((epoch  % 86400L) / 3600);
    Serial.print(hour); // print the hour (86400 equals secs per day)
    Serial.print(':');
    minute = ((epoch % 3600) / 60);
    if (minute < 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(':');
    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
  }
}

// send an NTP request to the time server at the given address
unsigned long sendNTPpacket(IPAddress& address) {
  //Serial.println("1");
  // 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)
  //Serial.println("2");
  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;

  //Serial.println("3");

  // 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
  //Serial.println("4");
  Udp.write(packetBuffer, NTP_PACKET_SIZE);
  //Serial.println("5");
  Udp.endPacket();
  //Serial.println("6");
}


void printWifiStatus() {
  // print the SSID of the network you're attached to:
  Serial.print("SSID: ");
  Serial.println(WiFi.SSID());

  // print your WiFi shield's IP address:
  IPAddress ip = WiFi.localIP();
  Serial.print("IP Address: ");
  Serial.println(ip);

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

Difficulty: 
Duration: 
Share a "Show & Tell" video.: 
https://www.youtube.com/watch?v=tlYKFbx3MFA
Collaborators: 
wyy170592
Number of Forks: 
0
Tools: 
Name: 
Arduino IDE
Quantity: 
1
Materials: 
Name: 
Generic 16x2 LCD display
Quantity or amount: 
1
Boards & Kits: 
Name: 
Realtek AM8195
Quantity: 
1
Team Members: 
Team member name: 
wyy170592
What role did this person play on the project?: 
Project Lead
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Teaser: 
Make a clock that gets the time from the internet, so you never have to worry if it is slow!
Show & Tell video as default: 
Creation Date: 
Thursday, February 27, 2020 - 18:54