btc-ticker.js

// Clear interval and timeout as they mess things up
clearInterval();
clearTimeout();
clearWatch();

// Setup WiFi
digitalWrite(B9,1); // enable on Pico Shim V2
Serial2.setup(115200, { rx: A3, tx : A2 });

const proxy = 'http://httptohttps.mrtimcakes.com/';
const api = 'https://api.cryptonator.com/api/ticker/';
const symbols = [ 'btc', 'ltc', 'eth' ];
const currency = 'gbp';
var prices = {
  btc: {},
  ltc: {},
  eth: {}
};

var h = require("http");
var g;

// Connect to wifi 
var wifi = require("ESP8266WiFi_0v25").connect(Serial2, function(err) {
  if (err) throw err;
  wifi.reset(function(err) {
    if (err) throw err;
    console.log("Connecting to WiFi");
    wifi.connect("SSID","PASSWORD", function(err) {
      if (err) throw err;
      // Get prices every 30 seconds
      setInterval(getPrices, 30000);
    });
  });
});

// Get the prices
function getPrices() {
  symbols.forEach(symbol => {
    let url = `${proxy}${api}${symbol}-${currency}`;
    h.get(url, function(res) {
      let pricesRaw = "";
      res.on('data', function(d) { pricesRaw += d; });
      res.on('close', () => {
        prices[symbol] = JSON.parse(pricesRaw);
      });
    });
  });
  showPrices();
}

// display the prices
function showPrices() {

  if(!prices[symbols[0]].hasOwnProperty('timestamp')) {
    return;
  }

  // Get pricetime from first symbol
  let priceTime = formatPriceTime(prices[symbols[0]].timestamp);
  g.clear();
  g.drawString(`Prices at: ${priceTime}`);  

  symbols.forEach((symbol, i) => {

    let base = prices[symbol].ticker.base;
    let price = parseFloat(prices[symbol].ticker.price).toFixed(2);

    g.drawString(`${base}: ${price}`, 0, (i+1)*16);

  });
  
  g.flip();
}

// format the price string
function formatPriceTime(timestamp) {
  let dt = new Date(timestamp * 1000);
  let minutes = dt.getMinutes().toString();
  let hours = dt.getHours().toString();
  let seconds = dt.getSeconds().toString();
  if(seconds.length < 2) seconds = `0${seconds}`;
  if(minutes.length < 2) minutes = `0${minutes}`;
  if(hours.length < 2) hours = `0${hours}`;

  return `${hours}:${minutes}:${seconds}`;
}

// Stuff for OLED
I2C1.setup({scl:B6,sda:B7});
require("Font6x8").add(Graphics);
require("Font8x16").add(Graphics);

// Draw the vars to the screen
function doDraw() {
    g.clear();
    g.drawString("Hello");
    g.drawString("Connecting...", 0,20);
    g.flip();
}

// Init the OLED Not really much point in this function
function initOLED() { 
  g = require("SSD1306").connect(I2C1,function(){
    g.setFont8x16();
    doDraw();
  }, { address: 0x3C });
}

// Start everything off
initOLED();