Introduction: $5 Power Meter
Lets build a $5 web based power meter and break open our usage to those with solutions to our antiquated grid and lifestyles.
This is a great start=> Real-time Web Based Household Power Usage Monitor
And here's a leading commercial product => TED
The device can serve residences, organizations, and communities trying to understand and reduce their energy use. .
The data will be hosted online so it can be audited by 3rd parties. The data might be hosted by Google's Power Meter and 3rd parties may gain access to market their energy savings solutions; such as, a new refrigerator, heating system, or efficient lights, etc.
Why do it? well the utilities are not going to... (they're old and slow moving) and the smart grid is a hoax.... and it should be kinda fun to show up the expensive, commercial products available.
Would you like to collaborate on a potential disruptive product?
Step 1: What Has Been Done So Far.....
What has been done so far........
Well beyond the cool instructables that I've already mentioned..... here is where this project is at:
Fabricated a prototype PCB using the ADE 7757 power meter IC (see schematic)
ADE7757 $3.20 - digikey
ADE7757 Analog Inputs
The current sensor (CT sensor) goes to pins V2p and V2n and supplies a max differential voltage of +/- 30 mV to the on board ADC.
The voltage leads go to pins V1N and V1P to supply a max differential signal of +/- 165 mV to the on board ADC.
ADE7757 Analog Outputs
The ADE7757 is a high accuracy electrical energy measurement IC. The ADE7757 supplies average real power information on low frequency outputs in the form of active low pulses with a relatively low pulse rate ~0.175 Hz.
A typical US residence requires qty(2) CT sensors to quantify energy usage. I've experimented with some inexpensive current sensors here.
Step 2: Programming
Read the Power
The CF pin on the ADE 7757 outputs a frequency. Here are two descriptions on how to read frequency using the Arduino Frequency Counter Library:
The Academy of Media Arts Cologne
Some list serve.......
Send the Power Data
Arduino Ethernet Shield and use the serverWrite() to send the data to any address. Is it really that easy?
Likely going to try to get a hold Google's API for their powermeter to help move the prototype along.
This guy hosts his own data here. Its a pretty neat application that logs the data locally and provides a nice graph.
The only problem is you need a computer ON 24/7 to grab and record the energy data. It would be nice for this data to be logged and displayed remotely.
Step 3: Design Goals
Grab real power in watts for the whole house usage (close to figuring out)
Broadcast the data over the home Ethernet/router to the hosted website (need to figure out)