Following on from yesterday’s experiments with an Arduino, a DHT22 temperature and humidity sensor, some Python and Cosm, a few developments.

First, I generalized and cleaned up the Python code and companion Arduino sketch, and you can now find these both, with some documentation, in a Github repository. This code improves error detection, and filters out the occasional out-of-range reading (like a 2300ºC temperature). It also sends the data to both Cosm and to Thingspeak.

Second, I brought my Belkin WeMo Switch into the office with hopes of wiring it up to this system: the Venta humidifier in the office doesn’t have a humidistat in it, only three fan speeds; I’m thinking that I should be able to set thresholds for turning it on, like “if the humidity is below 25% and it’s after 7:00 a.m., then turn on the humidifer.” Stay tuned for that.

Third, in Safari on my Mac I opened the Cosm feed for the temperature and humidity and the selected File | Open in Dashboard… from the menu.

I then selected the orange temperature “badge” from the page, and clicked Add and then did the same thing for the humidity badge:

The result is that on my Mac OS X Dashboard I now have the temperature and humidity in the office displayed: