{"id":315,"date":"2016-11-12T10:52:56","date_gmt":"2016-11-12T18:52:56","guid":{"rendered":"http:\/\/www.nathanbak.com\/?p=315"},"modified":"2026-01-02T20:04:41","modified_gmt":"2026-01-03T04:04:41","slug":"i-love-it-when-a-plan-comes-together","status":"publish","type":"post","link":"https:\/\/nathanbak.com\/?p=315","title":{"rendered":"I love it when a plan comes together"},"content":{"rendered":"

After spending a lot of effort and encountering difficulties in creating pieces, I am often pleasantly surprised when the pieces come together quickly and easily.\u00a0 This was the case for my latest home improvement tech project.\u00a0 In my home, it seems like some areas are warmer than others–I realized that some variance will exist, but I wanted to reduce the overall difference between upstairs and downstairs.<\/p>\n

The first step was to be able to measure the temperature or each area.\u00a0 Thanks to my ESP8266 development boards, I am able to publish the upstairs temperature and publish it to a database and Bakboard<\/a>.\u00a0 With the new Nest thermostat and a little playing with the REST API<\/a>, I was able to do something similar and publish the downstairs temperature to the BakBoard.\u00a0 There are now four temperatures published on the Bakboard<\/a>.<\/p>\n

\"temps\"<\/p>\n

I then wrote a simple Java program with that basically does the following:<\/p>\n

    \n
  1. Get the temperature of the [Downstairs] thermostat<\/li>\n
  2. Get the temperature of the [Upstairs] temperature sensor<\/li>\n
  3. If the difference between the two temperatures is greater than 2 degrees, turn on the furnace fan<\/li>\n<\/ol>\n

    I had a little trouble figuring out how to turn on the fan, but this is the way I implemented it in Java:<\/p>\n

    public void runFan(String thermostatId, String authToken) throws Exception {\r\n\u00a0\u00a0 \u00a0final String rootUrl = \"https:\/\/developer-api.nest.com\";\r\n\u00a0\u00a0 \u00a0HttpPut httpPut = new HttpPut(String.format(\"%s\/devices\/thermostats\/%s\/fan_timer_active\", rootUrl, thermostatId));\r\n\r\n\u00a0\u00a0 \u00a0StringEntity putEntity = new StringEntity(\"true\");\r\n\u00a0\u00a0 \u00a0httpPut.setEntity(putEntity);\r\n\u00a0\u00a0 \u00a0httpPut.addHeader(\"Content-Type\", \"application\/json\");\r\n\u00a0\u00a0 \u00a0httpPut.addHeader(\"Authorization\", \"Bearer \" + authToken);\r\n\u00a0\u00a0 \u00a0\u00a0\u00a0 \u00a0\r\n\u00a0\u00a0 \u00a0CloseableHttpClient httpclient = HttpClients.createDefault();\r\n\u00a0\u00a0\u00a0 try {\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 CloseableHttpResponse response = httpclient.execute(httpPut);\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \/\/ We need to handle redirect\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 if (response.getStatusLine().getStatusCode() == 307) {\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0 \u00a0String newUrl = response.getHeaders(\"Location\")[0].getValue();\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0 \u00a0httpPut.setURI(new URI(newUrl));\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0 \u00a0response = httpclient.execute(httpPut);\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 }\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 try {\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 HttpEntity entity = response.getEntity();\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 EntityUtils.consume(entity);\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 } finally {\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 response.close();\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 }\r\n\u00a0\u00a0\u00a0 } finally {\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 httpclient.close();\r\n\u00a0\u00a0\u00a0 }\r\n}<\/pre>\n
    Of course I want my code to run at regular intervals, but fortunately I had already figured out how to go about running a Java program every 15 minutes<\/a>.\u00a0 It was easy to toss everything into a Docker container and let it do its thing.<\/p>\n
    Here are a few notes\/design decisions that I made when putting things together:<\/p>\n