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Web platform / Web Platform - Ideal for Google Powermeter?
One of the reasons I became interested in the Web Platform was because it seemed ideally suited for use as a Google Powermeter appliance. For those of you not familiar with this, check out the introductory page here: http://www.google.com/powermeter/about/about.html
The principal is to continuously monitor your home energy usage and thus be able to identify inefficiencies allowing you to reduce consumption in an observable way. There are a couple of different ways to sense energy consumption including optical detection of the spinning wheel in a mechanical power meter, or clamp-on current transformers to sense the main split phase current feeding your home.
Google has defined an API such that you can feed your consumption information through the web for collection and subsequent analysis and graphical display.
It is possible to purchase devices that connect to your home and feed data to Google, but it can be much more rewarding to build and customize your own project.
There are a couple of things that make the Web Platform a very nice choice. First, it's small size, low cost, low power, and ethernet capability facilitate continuous unattended operation. The built-in ADC's can be used to connect the appropriate current sensor. Best of all however, is the fact that Microchip has a Google Powermeter demonstration application that is configured to run on a nearly identical dsPIC33 device. This should greatly reduce software development time.
You can learn more about the Microchip reference design here:
http://www.microchip.com/stellent/idcpl ... odeId=2889
This reference design comes as part of the Microchip Applications Libraries that are also used as the basis for the Web Platform firmware already familiar to those in this forum.
Also note that Seeed Studios sells suitable current sensing transformers for a very good price:
http://www.seeedstudio.com/depot/noninv ... th=144_154
I have taken the first step by making some alterations to the Microchip reference design, to reflect the hardware configuration of the Web Platform board. Although I managed to get it to build, it does not run, so there is plenty more work to do.
I will continue to hack my way along with this, but I am not really a serious programmer and it will probably take me quite some time to complete this project. I was wondering if there were others in this group who would be interested in collaborating on this project. I have ordered a couple of current sensors, and am still awaiting their arrival. There are two aspects to this - first, the hardware and interface to perform the measurement, and second, the software to interface with the Google API. I have some thoughts as to how I plan to approach the hardware side. The software interface seems more complicated to me but the Microchip reference design seems to go a long way in that direction.
Let me know if anyone has an interest in this project.
-Tom