Network Clock
Difficulty Index: ⭐⭐⭐⭐Suitable Age: 12+
Introduction
In fact, mobile phones and computers already have this capability.
To briefly introduce, this project uses the DS3231 clock module for automatic timekeeping. It is said that the annual error is less than one second (PS: I don’t really know if that’s true
I haven’t tested it for a whole year). A short press of the button connects to the internet to update and calibrate the time, while a long press puts it into configuration mode, eliminating the hassle of needing to modify the program when changing Wi-Fi passwords.
Just a reminder, the latest program for the weather broadcast project from issue 14 has added a configuration feature. Interested friends can enter the link below, find the Baidu Cloud mini program code at the bottom, and download it quickly. 

Materials Required
ESP8266 —– 1 piece
DS3231 Clock Module —– 1 piece
OLED Display IIC Interface —– 1 piece
10K Resistor —– 1 piece
Wires —– Several
Module Explanation
ESP8266: It’s a common topic.
DS3231 Clock Module: A professional timekeeping module that provides various time data. It also has a built-in temperature sensor, but its accuracy is questionable, with an error of ±2℃. Would you dare to use it?
It has a built-in 3V battery (the yellow object on the back), and it continues to run even when powered off. Once powered back on, it simply retrieves the time.
OLED Display: Uses an IIC interface and is responsible for displaying various information (time, prompts).
Wiring Diagram

Click to view the full image
Production Process


Reference Program
#include <RtcDS3231.h>#include <Wire.h>#include <U8g2lib.h>#include <SimpleTimer.h>#include <OneButton.h>#include <ESP8266WiFi.h>#include <DNSServer.h>#include <ESP8266WebServer.h>#include <WiFiManager.h> #include <TimeLib.h>#include <NtpClientLib.h>
wifiManager.resetSettings();wifiManager.autoConnect("NetClock");
Project Appreciation

Data Download
To obtain the materials for this project, please add the WeChat QR code below.





Recommended from Previous Issues:
【Issue 18】Challenge 100 Arduino Projects: Electronic Scale
【Issue 17】Mobile Remote Control Car
【Issue 16】Data Collection and Saving to Excel
【Issue 15】Distance Measuring Instrument
【Issue 14】Weather Broadcast from a Pen Holder
【Issue 13】Rock Paper Scissors Game Box 02
【Issue 12】Swimming Rescue Bracelet – Part 2
【Issue 11】Rock Paper Scissors Game Box 01
【Issue 10】Swimming Rescue Bracelet – Part 1
【Issue 9】Let’s Play Tug of War (2)
【Issue 8】Water Remote Control Car
【Issue 7】Let’s Play Tug of War (1)
【Issue 6】Vibration Fan
【Issue 5】Temperature and Humidity Detector
【Issue 4】Electronic Piano
【Issue 3】Radio
【Issue 2】Gesture Flow Light
【Issue 1】Ultrasonic Radar Detector