Solether - solar powered autonomous entity that lets you charge your phone for ethers

solether.js

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

// Solether - solar powered autonomous entity

var mraa    = require('mraa');
var _       = require('underscore')    // docs: http://underscorejs.org/
var Web3    = require('web3');

var account, balance, c, eth, geth_url, provider, web3;

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

c = console

//  geth_url = 'http://127.0.0.1:8545'
geth_url = "http://v.mkvd.net:8080"


provider = new Web3.providers.HttpProvider(geth_url)

web3 = new Web3(provider)

eth = web3.eth

c.log("web3 version:", web3.version.api)

//c.log("geth version:", web3.version.node);
//  account = eth.coinbase;

account = eth.accounts[2];
c.log("main account address:", account)

var account_to_watch = "0xe078de0afdf56936580521aac192fe0b2924c4f3"
account = account_to_watch

balance = eth.getBalance(account);
c.log("balance: ", Number(balance), "[account]")



var addr2watch = account

var check_balance = function(){
  bal = eth.getBalance(account);
  var ethers = Number(bal)
  //  console.log(".")
  console.log("b: ", ethers)

  // this is the simplest approach, just check if the balance if different from the previous one, meaning you can deposit any amount to charge your device
  // you could check if the price is increased by X amount or better if you got a transaction exactly of x ethz
  if (balance && balance != ethers)
    activate()

  if (light_is_on)
    reset_loops += 1

  balance = ethers

  if (reset_loops >= reset_after) {
    reset_loops = 0;
    relayPin.write(0) // set the relay pin to low, this will trigger the relay!
    _.delay(function(){ relayPin.write(1) }, 5000) // this is like setTimeout(check_balance, loop_Time)
    light_is_on = false;
    console.log("time's up, switching it off")
  }

  _.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, " ")
  console.log("Here's your charge!")
  light_is_on = true
  relayPin.write(0) // set the relay pin to low, this will trigger the relay!
  _.delay(function(){ relayPin.write(1) }, 100) // this is like setTimeout(check_balance, loop_Time)
}

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("EtherSwitch initialized - v0.2.0 - watching address:", addr2watch)
  check_balance()
}


main()