Logging Nest Thermostat Data: Update 1

I have updated my Nest thermostat data logger. The changes are as follows:

1. added fan status, heater status, and AC status.
2. polling interval increased from 15 min to 1 min.
3. data are pushed to ThingSpeak only if at least one field changes.

The new node.js code:

[code language=”java”]
"option strict";
var util = require(‘util’),
ThingSpeakClient = require(‘thingspeakclient’);
nest = require(‘unofficial-nest-api’); // get from npm

process.on(‘uncaughtException’, function(err) {
// handle the error safely
console.log(err);
});

// nest parameters
var username = ‘YOUR-NEST-LOGIN’;
var password = ‘YOUR NEST PASSWORD’;

// thingspeak parameters
var channelId = YOUR-THINGSPEAK-CHANNEL-ID;
var apiKey = ‘YOUR THINGSPEAK-WRITE-API-KEY’;

// update interval in ms
var updateInterval = 1000*60;

var tsclient = new ThingSpeakClient();
tsclient.attachChannel(channelId, { writeKey:apiKey});

var setTemp = 0;
var curTemp = 0;
var curHum = 0;
var curFanState = -1;
var curHeaterState = -1;
var curACState = -1;

function trimQuotes(s) {
if (!s || s.length === 0) {
return ”;
}
var c = s.charAt(0);
var start = (c === ‘\” || c === ‘"’) ? 1 : 0;
var end = s.length;
c = s.charAt(end – 1);
end -= (c === ‘\” || c === ‘"’) ? 1 : 0;
return s.substring(start, end);
}

function merge(o1, o2) {
o1 = o1 || {};
if (!o2) {
return o1;
}
for (var p in o2) {
o1[p] = o2[p];
}
return o1;
}

function fetchData(data) {
nest.login(username, password, function (err, data) {
if (err) {
console.log(err.message);
//process.exit(1);
return;
}

nest.fetchStatus(function (data) {
for (var deviceId in data.device) {
if (data.device.hasOwnProperty(deviceId)) {
var shared = data.shared[deviceId];
var date = new Date();
var time = date.getFullYear()+’/’+date.getMonth()+’/’+date.getDate()+’-‘+date.getHours()+’:’+date.getMinutes();
var cTemp = nest.ctof(shared.current_temperature);
var sTemp = nest.ctof(shared.target_temperature);
var cHum = data.device[deviceId].current_humidity;
var cFanState = (shared.hvac_fan_state == true) ? 1 : 0;
var cHeaterState = (shared.hvac_heater_state == true) ? 1 : 0;
var cACState = (shared.hvac_ac_state == true) ? 1 : 0;

console.log(util.format("%s %s [%s], cur temp: %d F cur humidity: %d %% set temp: %d fan: %s heat: %s AC: %s",
time,
shared.name, deviceId,
cTemp,
cHum,
sTemp,
cFanState ? ‘on’ : ‘off’,
cHeaterState ? ‘on’ : ‘off’,
cACState ? ‘on’ : ‘off’
));
if ((cTemp !== curTemp) || (cHum !== curHum) ||
(sTemp !== setTemp) || (cFanState !== curFanState) ||
(cHeaterState !== curHeaterState) ||
(cACState !== curACState)) {
var tsData = new Object();
tsData.field1 = cTemp;
tsData.field2 = cHum;
tsData.field3 = sTemp;
tsData.field4 = cFanState;
tsData.field5 = cHeaterState;
tsData.field6 = cACState;
console.log("sending to thingspeak");
tsclient.updateChannel(channelId,tsData);
}
curTemp = cTemp;
curHum = cHum;
setTemp = sTemp;
curFanState = cFanState;
curHeaterState = cHeaterState;
curACState = cACState;
}
}
});
});
}

fetchData();
setInterval(fetchData,updateInterval);
[/code]

The corresponding ThingSpeak Channel also needs to have 3 new fields added to it:

1. Field 4: Fan State
2. Field 5: Heater State
3. Field 6: AC State

I am currently running the demo on a Raspberry Pi. As before, you can view my live channel on ThingSpeak: Nest Logging Demo

I will be updating the code from time to time.  You can always get the latest version from github: lincomatic/nest-thingspeak

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