This project documents my adventures in learning how to wire up my home for wireless power monitoring. I live in a rented apartment so I don't have hacking-access to a meter or breaker panel. Since I'm still very interested in measuring my power usage on a long term basis, I built wireless outlet reporters. Building your own power monitor isn't too tough and can save money but I'm not a fan of sticking my fingers into 120V power. Instead, I'll used the existing Kill-a-watt power monitor, which works great and is available at my local hardware store.
My plan is to have each room connected to a 6-outlet power strip which powers all the devices in that room (each kill-a-watt can measure up to 15A, or about 1800W, which is plenty!). That way I can track room-by-room usage, for example "kitchen", "bedroom", "workbench", and "office".
Each wireless outlet/receiver can be built for ~$55 with a few easily-available electronic parts and light soldering, no microcontroller programming or high voltage engineering is necessary!
You can see my setup including graphs and reports at http://twitter.com/tweetawatt
If you'd like to build one for yourself
1. Buy a kit: get all the parts you need, there's a starter kit at the adafruit webshop
2. Make: turn each Kill-a-Watt into a wireless power level transmitter
3. Software: Download & run it on your computer to get data and save it to a file and/or publish it
If you want to know how it was made, check out:
1. Listen: write simple software for my computer (or Arduino, etc) to listen for signal and compute the current power usage
2. Store: Create a database backend that will store the power usage for long-term analysis at http://wattcher.appspot.com
3. View: Graph and understand trends in power usage
Check out the latest readings at http://wattcher.appspot.com
Step 1: Make it!
You should only attempt this project if you are comfortable and competent working with high voltage electricity, electronics and computers. Once the project is complete it is enclosed and there are no exposed high voltages. However, you must only work on the project when its not plugged in and never ever attempt to test, measure, open, or probe the circuitboards while they are attached to a wall socket. If something isn't working: stop, remove it from the wall power, then open it up and examine. Yes it takes a few more minutes but it's a lot safer!
Your safety is your own responsibility, including proper use of equipment and safety gear, and determining whether you have adequate skill and experience. Power tools, electricity, and other resources used for this projects are dangerous, unless used properly and with adequate precautions, including safety gear. Some illustrative photos do not depict safety precautions or equipment, in order to show the project steps more clearly. This projects is not intended for use by children.
Use of the instructions and suggestions is at your own risk. Adafruit Industries LLC, disclaims all responsibility for any resulting damage, injury, or expense. It is your responsibility to make sure that your activities comply with applicable laws.
OK, if you agree we can move on!
Make a tweet-a-watt
To make the tweet-a-watt setup, we will have to go through a few steps
1. Prepare by making sure we have everything we need and know the skills necessary to build the project
2. Build the receiver setup by soldering up one of the adapter kits
3. Configure the XBee wireless modems
4. Build the transmitter setup by modifying a Kill-a-Watt to transmit via the XBee
5. Run the software, which will retrieve data and save it to a file, upload it to a database and/or twitter