BitSwitch Intel Edison sample using Node.js - #bitcoin #bitswitch #iot #edison #automation #relay #io - video: https://www.youtube.com/watch?v=gmdZxiMekOk

bitswitch_intel_edison_main.js

/*jslint node:true, vars:true, bitwise:true, unparam:true */
/*jshint unused:false */
/*global */

var mraa    = require('mraa');     
var request = require('request') // https://github.com/request/request
var _       = require('underscore')    // docs: http://underscorejs.org/

var addr2watch  = '1PzTDHe2GKjv2sHHKoN4Gbu2njLtekkYHh' // bitcoin address to watch 
var loop_time   = 1000  // ms   (check every second)
var balance     = null
var relayPin    = new mraa.Gpio(12)
var reset_loops = 0
var light_is_on = false

var reset_after = 30 // seconds

var check_balance = function(){
  // this version uses blockchain.info direct api - but I could've used blockr.io, blockcypher, etc... prefer the ones that don't require an access keys
  request('https://blockchain.info/q/addressbalance/'+addr2watch, function (error, response, body) {
    if (!error && response.statusCode == 200) {
      var satoshi = parseInt(body)
      var btc = satoshi*Math.pow(10, -8)
      
      // this is the simplest approach, just check if the balance if different
      // you could check if the price is increased by X amount or better if you got a transaction exactly of x btc
      if (balance && balance != btc)
        activate()
      
      if (light_is_on) 
        reset_loops += 1
        
      balance = btc
    }
    if (reset_loops >= reset_after) {
      reset_loops = 0;
      relayPin.write(1);
      light_is_on = false;
    }
    
    _.delay(check_balance, loop_time) // this is like setTimeout(check_balance, loop_Time)
  })
}

var activate = function() {
  console.log("Address balance changed, new one is:", balance, "BTC")
  console.log("Let there be light!")
  light_is_on = true
  relayPin.write(0) // set the relay pin to low, this will trigger the relay!
}

var main = function() {
  console.log('MRAA Version: ' + mraa.getVersion());
  relayPin.dir(mraa.DIR_OUT);
  relayPin.write(1);  // I have my relay as normally closed (NC). otherwise, if it's normally open (NO) you have to invert the 0 and 1 in all the .write() calls
  
  console.log("BitEdison initialized - v0.1.0 - watching address:", addr2watch)
  check_balance()
}


main()

VIDEO: https://www.youtube.com/watch?v=gmdZxiMekOk