Not long ago I received my third hardware example of the BeerBug, namely the current WiFi model. Previously I had tested two previous incarnations that connected to the world using Bluetooth (see my blog posts tagged beerbug). After seeing some good looking data from the new models, I took advantage of a reasonably priced upgrade process offered to Kickstarter backers to get the latest version.
Initial impressions were pretty good. It has more LEDs than the earlier model to provide more information (though these could be documented better), and an integrated LiPo battery that so far has provided outstanding battery life compared to the older Bluetooth prototypes. This BeerBug uses the Electric Imp platform to connect to a remote server using your home WiFi network, and from there data is accessible by smartphone apps and a web interface. The hardware gets configured for home wifi by something they call blinkup where your smartphone flashes a coded signal onto a receiver on top of the device. It is nice being able to see the data from anywhere you have internet connection, especially compared to the older version which required a windows device in bluetooth range.
I’d made a simple PVC holder to allow the “torpedo” weight to hang in sanitizing solution or water without occupying a fermentor, and used this to check the performance of the device. Here the optional temperature sensor dangles alongside.
The software is not fully developed yet, though I thought it was in better shape that the earlier versions I had spent many hours trying to get working, exchanging dozens of emails with the ParasitX crew. This time I was stymied trying to get the Android app to tare (i.e., calibrated to 1.000 specific gravity in water), receiving a message saying “did not receive a response from the imp servers.” I thought I had a network firewall issue which led me down a fruitless path of trying to reconfigure my router and DSL modem. Eventually I installed the iOS app and got the thing tared. Even later I found that there is the ability to tare from the web interface, though this option was difficult to see.
I haven’t tested it in brewing yet, but here are some results from testing in water as I have done before, to check for drift, accuracy, precision, etc. The very first run, below, had pretty quick drift up to about 1.005 in the first day or two but after that was steady with small variations of about +/- 0.002 specific gravity units.
On around August 28 I tared it to re-zero at 1.000. Instead of a vertical line in the chart as might be expected, there is at least one intermediate data point going down to after the completion of the tare, which is strange (see below chart). I wonder if this is some sort of smoothing algorithm. After having looked at some of the raw data from the bluetooth devices, I don’t miss seeing it, though the scientist in me is a bit put off seeing a data point (as opposed to an interpolated line) where there should be none.
Anyway, once I got the device set up initially it seemed to be working quite well overall with better consistency and usability than the bluetooth prototypes. Supposedly the WiFi will connect from inside a refrigerator. I look forward to using it with a beer.