index.js

const {ESP8266HTTPClient} = require('@niklauslee/esp8266-http-client');
const {SSD1306} = require('@niklauslee/ssd1306-i2c');
const font = require('@niklauslee/font-minimal');
const logo = require('@kaluma/logo-mono');

const esp8266 = new ESP8266HTTPClient(null, {debug: true});
const ssd1306 = new SSD1306();

const REQ_INTV = 1000 * 60 * 60 * 2; // 2 hours
const UPD_INTV = 1000; // 1 seconds
const WEEK = ['SUN', 'MON', 'TUE', 'WED', 'THU', 'FRI', 'SAT'];

var gc = null; // graphic context
var time = 0; // current time
var requestError = false;

function digit2 (num) {
  var ns = num.toString();
  if (ns.length === 1) ns = '0' + ns;
  return ns;
}

function update () {
  var t = time + millis();
  var date = new Date(t);
  var h = date.getHours();
  var am = true;
  if (h > 12) {
    h = h - 12;
    am = false;
  }
  var m = date.getMinutes();
  var month = date.getMonth() + 1;
  var day = date.getDate();
  var dw = WEEK[date.getDay()];  
  gc.clearScreen();
  gc.setFontScale(6, 6);
  gc.drawText(5, 23, `${digit2(h)}:${digit2(m)}`);
  gc.setFontScale(2, 2);
  gc.drawText(5, 5, `${dw} ${digit2(month)}-${digit2(day)}`);
  gc.drawText(105, 5, am ? 'AM' : 'PM');
  if (requestError) {
    gc.setFontScale(1, 1);
    gc.drawText(5, 59, 'FAILED TIME REQUEST');
  }
  gc.display();
}

function request () {
  esp8266.http('http://worldtimeapi.org/api/ip')
    .then(res => {
      console.log(res);
      var data = JSON.parse(res.body);
      var unixtime = data.unixtime + data.raw_offset;
      time = (unixtime * 1000) - millis();
      requestError = false;
    })
    .catch(err => {
      console.log(err);
      requestError = true;
      update();
    });  
}

// setup SSD1306
ssd1306.setup(board.i2c(0), {width: 128, height: 64}, () => {
  console.log('SSD1306 initialized');
  gc = ssd1306.getContext();
  gc.setFont(font);
  gc.clearScreen();
  var x = Math.round((gc.getWidth() - logo.width) / 2);
  var y = Math.round((gc.getHeight() - logo.height) / 2);
  gc.drawBitmap(x, y, logo);
  gc.display();
  // setup ESP8266
  console.log('connecting Wi-Fi...');
  esp8266.wifi().then(() => {
    console.log('Wi-Fi connected');
    setInterval(request, REQ_INTV);
    setInterval(update, UPD_INTV);
    request();
  }).catch(err => {
    console.log(err);
    gc.clearScreen();
    gc.drawText(0, 20, 'Unable to connect\nWiFi network');
    gc.display();
  });
});