Clocks with no Knobs

This digital clock has no setting or control knobs because the date and time are automatically set using the accurate internet time. Email parts@robotsforfun.com to get the parts for this project.

Before you attempt to do this, you need to first know how to work with the ESP8266 WiFi module.

Parts needed:
  • ESP8266-12
  • Jumbo 7-segment common cathode LED displays 5x
  • MAX7219 controller
  • UDN2981A
  • 9V to 3.3V converter
  • 9V power supply
  • Wires
  • Soldering iron
internet clock internet clock internet clock
1 Connect the MAX7219 to the 7-segment displays as follows:
  • DIG0 to DIG4 to each of the display's common cathode
  • SEGA to SEGG and SEGDP to the eight inputs of the UDN2981A
  • The eight outputs of the UDN2981A to the display's segments
2 Here's the code. It's real long! 
/*
 * 5 digit x 7 segment LED with NO colon display clock using the MAX7129
 * Digits: Common cathode
 * D0 is the leftmost digit
 * 
 * Connections:
 * MAX7219       ESP8266
 * DIN pin 1  to pin D14
 * CLK pin 12 to pin D12
 * CS  pin 13 to pin D13
 * 
 * After uploading this program to the ESP8266-12 module,
 * open the serial monitor and restart the ESP8266 module to 
 * see what IP address is assigned to this webserver,
 * then browse to this IP address.
 * 
 * or
 * 
 * Connect your WiFi to the default ssid 
 *     "WiFi setup ESP8266-xxxx"
 * or to the one you provided, then browse to the IP address
 *     1.2.3.4 
 * for the main page or
 *     1.2.3.4/setup
 * for the WiFi setup page
 * 
 * If the WiFi is not connected then you will have to go to
 * 1.2.3.4/setup to setup the ssid and password
 * 
 * Copyright 2020 Enoch Hwang
 */

 
//////////////////////////////////////////////////////////////
//// VCC voltage stuff
  ADC_MODE(ADC_VCC);


//////////////////////////////////////////////////////////////
//// status LED stuff
#define statusLed 2     // for ESP8266-12


//////////////////////////////////////////////////////////////
//// NTP clock stuff
#include "DateTime_RobotsForFun.h"


//////////////////////////////////////////////////////////////
//// WiFi stuff
#include "WiFi_RobotsForFun.h"

// Do delay without using the delay() function
void nonblockingDelay(int wait) {
  unsigned long timesUp;
  timesUp = millis() + wait;
  while (millis() < timesUp) {
//    flashActivityLed();
    server.handleClient();
    yield();  // must have this to give time to handle wifi background stuff
  }
}


//////////////////////////////////////////////////////////////
//// HTML webpage 
void indexHTML() {
  String msg = "";
  msg += "";
  msg += "";
  msg += ""; // keep fonts consistent between devices
  msg += ""; // auto refresh page every 1 second
  
  msg += "LED Clock";
  msg += "  ";
  msg += "";
  
  msg += "";
  msg += "
Jumbo LED Network Clock
";
  msg += "Real time clock for the
5x7 segment LED display
using the MAX7219 controller";
  msg += "
" + formattedTime() + "";
  msg += "
";
  msg += "
";

  if (!isTimeValid()) {
    msg += "
";
    msg += " Year: ";
    msg += " Month: ";
    msg += "       Day: ";
    msg += "
Hour: ";
    msg += "     Minute: ";
    msg += " Second: ";
    msg += "
";
    msg += "
";
    msg += "
";
  }
  
  // wifi setup and info links
  msg += "IP address: ";
  if (wifiIsConnected) {
    msg += "" + WiFi.localIP().toString() + "";
    msg += "
Wifi setup and info: ";
    msg += "" + WiFi.localIP().toString() + "/setup";
  } else {
    msg += "1.2.3.4";
    msg += "
Wifi setup and info: ";
    msg += "1.2.3.4/setup";
  }

  msg += "";
  msg += "";

  // send webpage to browser
  server.send(200, "text/html", msg);

  // get url arguments and process the command that DO have time delays
  if (server.hasArg("YR")) {
    // set the clock
    int yr, mo, da, hr, mi, se;
    yr = server.arg("YR").toInt();
    mo = server.arg("MO").toInt();
    da = server.arg("DA").toInt();
    hr = server.arg("HR").toInt();
    mi = server.arg("MI").toInt();
    se = server.arg("SE").toInt();
    if (yr == 0) yr = year();
    if (mo == 0) mo = month();
    if (da == 0) da = day();
    if (hr == 0) hr = hour();
    if (mi == 0) mi = minute();
    setClock(yr, mo, da, hr, mi, se);
  }
}


//////////////////////////////////////////////////////////////
//// MAX7219 7x5 LED display stuff
#include "LedControl.h"
#define DIN 14
#define CS  12
#define CLK 13
#define NO 1  // number of MAX72XX devices connected
LedControl led = LedControl(DIN, CLK, CS, NO);
int brightness = 15; // 15=max bright
bool hr12 = true;

void displayClock() {
  const static char w10[7] = {'S','M','T','W','T','F','S'};  // The "T" is changed in the LedControl.h definition
  const static char w1[7]  = {'u','o','u','d','h','r','A'};

  time_t t = time(nullptr);   // get current date/time
  struct tm st = *gmtime(&t); // convert to time structure
  int h = hour12(st);         // extract the parts
  int h24 = hour(st);
  int m = minute(st);
  int s = second(st);
  int w = weekday(st);        // 0=Sunday
  int mo = month(st);
  int d = day(st);
  
  int h10 = h/10;             // separate the 10th and unit digits
  int h1 = h - h10*10;
  int m10 = m/10;
  int m1 = m - m10*10;
  int s10 = s/10;
  int s1 = s - s10*10;
  int mo10 = mo/10;
  int mo1 = mo - mo10*10;
  int d10 = d/10;
  int d1 = d - d10*10;

  // set brightness depending on time of day
  if (h24 < 5) led.setIntensity(0, 2);  // set the brightness
  else if (h24 >= 5 && h24 <= 22) led.setIntensity(0, 15);
  else led.setIntensity(0, 7);

  if (s1 < 7) { // display hour, minute
    led.setDigit(0, 0, h10, false);
    led.setDigit(0, 1, h1, false);
    led.setDigit(0, 3, m10, false);
    led.setDigit(0, 4, m1, false);
//    led.setLed(0, 2, 7, false);     // turn digit 2, segment 7 off
//    led.setLed(0, 2, 3, false);
//    led.setLed(0, 2, 5, true);      // turn digit 2, segment 5 on
    led.setChar(0, 2, ' ', true);     // turn on digit 2 decimal point
    nonblockingDelay(500); // flash the dot
//    led.setLed(0, 2, 7, false);
//    led.setLed(0, 2, 3, true);
//    led.setLed(0, 2, 5, false);
    led.setChar(0, 2, ' ', false);     // turn off digit 2 decimal point
  } else { // display weekday, day
    led.setChar(0, 0, w10[w], false);
    led.setChar(0, 1, w1[w], false);
    led.setChar(0, 2, '-', false);
    led.setDigit(0, 3, d10, false);
    led.setDigit(0, 4, d1, false);    
  }
}

void setup() {
  Serial.begin(115200);
  pinMode(statusLed, OUTPUT);

  //// MAX7219 LED display stuff
  led.shutdown(0, false);  // The MAX72XX is in power-saving mode on startup
  led.setIntensity(0, 15);  // set the brightness 15=max
  led.clearDisplay(0);
  led.setChar(0, 0, 'C', false);
  led.setChar(0, 1, 'o', false);
  led.setChar(0, 2, 'n', false);
  led.setChar(0, 3, 'n', false);
  led.setChar(0, 4, '-', false);

  //// WiFi stuff
  char devicename[] = "Jumbo LED clock";   // optional. change to whatever you want. Use "ping ESP8266" to test
  setupAP(devicename);  // setup access point using default ssid "WiFi setup ESP8266-xxxx" and no password
  IPAddress staticIP(192, 168, 1, 54);     // for the Jumbo LED Network clock
  bool blocking = false;
  if (!setupWiFi(devicename, staticIP, blocking)) {
  // if (!setupWiFi(devicename, blocking)) {   // use DHCP
    led.setChar(0, 0, 'F', false);
    led.setChar(0, 1, 'A', false);
    led.setChar(0, 2, 'I', false);
    led.setChar(0, 3, 'L', false);
    // block for 3 minutes
    unsigned long timeout = millis() + 180000; // 3 minutes
    while(millis() < timeout) {
      flashActivityLed(3000,150,1);
      server.handleClient();
      yield();  // must have this to give time to handle wifi background stuff
    }
    ESP.restart();  // have not connected to the internet in 3 minutes so just reboot
  }
  // connected to wifi

  // set the clock
  while (!setClock(PST)) {
    delay(1000);
  }

  // update systemStartTime and systemStartCount
  systemStartTime = now();
  EEPROM.get(EEPROM_ADDRESS_systemStartCount, systemStartCount);  // get systemStartCount from EEPROM
  systemStartCount++;
  EEPROM.put(EEPROM_ADDRESS_systemStartCount, systemStartCount);
  EEPROM.commit();

}

void loop() {
  static time_t prevDisplay;
  if (now() != prevDisplay) { //update the display only if time has changed
    prevDisplay = now();
//    Serial.println(formattedTime());
    displayClock();
  }
  
  if (APisOn && (millis() > 600000)) turnOffAP(); // turn off AP after 10 minutes
  flashActivityLed();
//  checkWifiConnection();  // reboot if wifi is disconnected
  syncClock(); // need to call this frequently to sync the clock
  server.handleClient();
}

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