When you need a cold one and walking downstairs to your twin-keg refrigerator just won’t do, it’s time to break out the tools to deliver that frothy goodness where it’s needed. And so began [DaveLondres’] inspiring tale of piping beer through the walls of his home.
Now we know what you’re thinking… that beer is going to get mighty warm sitting in long lines from the fridge up to the ground floor. [Dave] thought about that too and designed a double-pipe system to overcome the issue. A run of PVC pipe for each keg connect the in-wall taps to holes drilled in the side of a second-hand fridge. An ingenious branching job yields an extra port for each run which was fitted with computer case fans to keep the cold air circulating. Plastic tubing is snaked inside of the PVC to carry the beer.
Rounding out the craftsmanship on this one is the inclusion of a plumbed drain to whisk away the drippings. If you’re not going to have a beautifully adorned chest-freezer-gone-kegerator in your livingroom this is the best alternative we’ve seen.
[via reddit]
So he figured out a way to extract data from the existing meters. For the Electricity meter, he thought of using current clamps, but punted that idea considering them to be suited more for instantaneous readings and prone for significant drift when measuring cumulative consumption. Eventually, he hit upon a pretty neat hack. He took a slot type opto coupler, cut it in half, and used it as a retro-reflective sensor that detected the black band on the spinning disk of the old electro-mechanical meter. Each turn of the disk corresponds to 4 Watt-hours. A little computation, and he’s able to deduce Watt-hours and Amps used. The sensor is hooked up to an Arduino Pro-mini which then sends the data via a nRF24L01+ module to the main circuit located inside his house. The electronics are housed in a small enclosure, and the opto-sensor looks just taped to the meter. He has a nice tip on aligning the infra-red opto-sensor – use a camera to check it (a phone camera can work well).
