A node script for a raspberry pi which collects temperature data and logs it to a .csv

ColdPi

var fs = require('fs');
var path = require('path');
var gpio = require('gpio');
var filePath = path.join(process.cwd(), 'log.csv');

var tempSensor = gpio.export(4, {
  direction: 'in',
  interval: 5000,
  ready: startApp
});

var indicator = gpio.export(5, {
  direction: 'out'
});


var updateCSV = function(newTemperature){
  var csv = fs.readFileSync(filePath, { encoding: 'utf8' });
  console.log(csv);
  csv += [
    newTemperature,
    new Date().getTime(),
    '\n'
  ].join(', ');

  fs.writeFileSync(filePath, csv, { encoding: 'utf8' });

  indicator.set(0);
};


var startApp = function(){
  tempSensor.on('change', function(temperature){
    indicator.set(1);

    setTimeout(function(){
      updateCSV(temperature);
    }, 2000);
  });
};