Thermometer

(Really Expensive)

Welcome to the Internet of Silly Things....IoST.

I had a Phidgets USB board sitting around, and 5 temperature sensors, and time on my hands, so I finally got around to hooking them up to a computer, added some python code to read the sensors and write the temperature values to a rollover log file, added some python code to read the latest finished log and transfer the values to a db at my website, and added some PHP to read the DB, and draw a graph of temperatures at times of day.

And thus, the world's most expensive home thermometers; a computer on 24/7 to run the board hardware and logging software, an internet, an ISP providing the machines to support the remote database and provide page views.


Here are a couple of canned links.

or use a datepicker


Of course, one thing leads to another. I found one can download historical weather data from various weather stations maintained by Environment Canada. I found the station closest to my house, and downloaded all the 2018 records for that station and added them to a new database. And then reused my thermo code to access the new database.

So far, I have the one year and one station, but the rest is just a matter of downloading more data....

or use a datepicker for the EC data

or use a history picker for the EC data


details


Of course, much later (autumn 2023) a pile of things leads to another thing. Phidgets has sensors for Humdity and Temperature in one unit, and Air Pressure in another, so of course we end up with the most expensive Humidito-Thermo-Baro-meter and yet another date picker for the humidity temperatute and pressure data, all in one graph.

I opted for one graph that shows three completeley different units, because the perversity of it appeals.

Thus we have a y-axis from 0 to 100, for Relative Humidity (0 - 100 %), a y-axis from 95-105 for air pressure in kPa, and a y-axis from -25 to +40 degrees Celsius.

With this in hand, I may someday display Humidex, using a table based on Temperature and Relative Humidity, though Canada computes it from Dew Point.

I add a tiny offset to the raw data to agree with EC GC CA for YYZ. I will probably have to show Pressure in a new graph on its own scale as the daily changes are very small relative to the swings in Humidity and Temperature.

The data are read when a reading in the Phidget exceeds a trigger value; this smooths the curves. I am still working on best trigger values for a low number of readings that still maintains the gist of the changes for the day.