Over the years, I have collected a curious bunch of temperature measuring devices. Bright yellow analog thermometers that are a disgrace to beautiful aquariums. Digital ones that measure all over the place when the probes get soggy, or due to some electromagnetic interferences, or when the button cells slowly die. And various devices with hardly readable screens that pull in their wireless data via some sensor.
Some years ago I was looking into a wireless temperature monitoring solution for a mid-size company. Got quotes from a few suppliers, and it ended up being around 20 Grand and too limited at that.
Looking at the many cheap contraption with wireless sensors that greet visitors at my door, I figured there must be some affordable way to do this by now. So a few days ago I started my search
First, I found USB sticks that collect data. They are often used to track temperatures during transits, and you have to download the data to analyze it. I wanted to be able to look at my data in real-time, so no good.
Then, I looked at some weather stations which can be connected to a computer to download the data that is collected. Actually, they have to be connected to a computer, which is a minus. Also, they do a lot more than I wanted (and along with that cost more than I wanted to spend), and the reliability seems to be questionable for the cheaper units.
Finally, I came across this unit
. Besides being moderately priced, it seemed to do exactly what I wanted, and then some. So I quickly went ahead and ordered it...
And received it two long days later.
Unwrapped it, and studied the short instructions: Plug Gateway into router to transfer your temp measurements to a website, push a button, register at website, check. Unpack sensors, push button, register at website, check.
The Gateway comes with a "free" weather station that pulls info from the web. While I didn't really want it, it's actually neat to see if it will rain or freeze tomorrow.
Once everything worked, I distributed the six sensors throughout house and garden. What's nice is that each sensor has a detachable probe (for your fish tanks, of course), so you get effectively two readings from each unit. 12 readings for me. For example, you measure the outside temperature (and humidity), and the probe hangs in the pond and tells you if the goldies are freezing or boiling.
Next, I looked at the website to make sure data is collected. Indeed, there are my 6 sensors, sensing temps and humidity.
Each sensor shows a couple of recent measurements, so you'll know if the link is working. During the first night I lost a link to the furthest sensor. It returned in the morning, but placing the gateway at a higher spot seems to have improved the situation.
For a quick look at all temps (maybe at the cell phone of your choice), they provide a link too:
Now for the interesting part... they data is collected into a tab-delimited file which can be opened with Excel. Personally, I prefer Access to do data collection and mining, so I import the measurement log into a database and work with it from there.
Here is what all 12 sensors look like when displayed in an Access pivot chart:
While this won't tell you
much, it provides me with lots of joy for many hours. Now I can exactly see what happens when I add a fan here, remove a bulb there, or open a door here. It tells me whether the heater in my garage aquarium is sufficient, and how outside temperatures affect temperature in my pond. The large swings on top, for example, are the temperature of the canopy, showing when the first set of bulbs kick in, then the second, etc.
Oh yeah, and you can have an alert sent to your phone/email if something seems out of range, a signal is lost, or a battery is starting to lose charge.