Current-Cost This is just a quick note to spotlight the fact that Home.API now has native support for the Current Cost EnviR smartmeter.

Setting it up

Check out the latest version of Home.API from the Github repository, and then attach the plugin to an endpoint by adding a definition to a .conf file in your def directory. E.g.

# Current cost envir
     class \power\smartmeters\CurrentCostEnviR

This will install the plugin using the default parameters, but you can override these by specifying them in your definition. Available parameters are:

  • port, which defaults to '/dev/ttyUSB0'
  • baud, the baud rate to connect to, defaulting to 57600
  • timeout, defaulting to 10 seconds.

Your Current cost meter should be connected to the same machine as your Home.API install, and the web server user granted access to the comm port the device is connected to.

Exposed API

Once you have enabled the Current Cost plugin, you should see a new entry appear on your Home.API dashboard which gives a quick summary of the information retrieved from the device. It also makes available a number of functions which you can query at your endpoint (http://home.api/api/path/to/endpoint/), and these are:

  • time.json: Retrieve the time from the device.
  • temp.json: Retrieve the temperature from the device.
  • power.json: Retrieve the power in watts from the device.
  • latest.json: Retrieve all of the above at once, and return them as an array.

Visit the endpoint in your browser and see it working!

Current-CostThe current cost meter is an electricity monitoring device which attaches to your house’s electricity meter. It gives you a read out of how much electricity you are using at any given time, and how much that electricity is costing you.

One of the cool things about the Current Cost meter, verses other meters which are out there, is that it includes a data cable. This cable attaches the meter to your computer, and you are able then to extract usage data, very simply, over a serial connection.

So, riffing off the weather display tool I wrote a few weeks ago, here is a quick tool for extracting electricity usage data from your Current Cost meter, and outputting it in a customisable format. The tool is tested on Linux against a Current Cost EnviR, but it may well work with other meters in the range.

Since the first step towards any form of optimisation is to collect data, my plan is to use this tool to graph my electricity usage over time, and hopefully reduce my running costs a bit. Anyway, code up on GitHub as usual!

» Visit the project on Github…