This experimental exercise is for exposing home energy consumption figures to cellular phone real time. Solution utilizes Wattson energy meter and RaspBerryPI. Watsson is used for actual energy consumption and RaspBerryPI for exposing figures to phone via Internet connection. Exercise makes use of several great tutorials and open source libraries.

1. Home energy consumption
Interested what is your home energy consumption at
some point of time you are away?
Want current consumption on your phone UI real
time?
If yes, read further
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2. About this presentation
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Instructions are on high level
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Some tasks may not be needed
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Some tasks may be missing
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3. HW-Components
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Wattson energy meter
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Raspberry PI
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(Internet connection)
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4. SW-components / Rpi
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Open Wattson C-library (For reading current power from Wattson-device
by Raspberry)
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Available at: http://dialog.hut.fi/openwattson/
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5. SW-components / Android Widget
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Tutorial for implementing Android
Widget (For showing power on your
Android device)
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Available at:
http://www.vogella.com/articles/A
ndroidWidgets/article.html
Tutorial for Android http-connection
(For reading power from Raspberrybased web server)
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Available at:
http://www.vogella.com/articles/A
ndroidNetworking/article.html
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6. SW-components / iOS app
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Tab-based application, current power by
button on one tab and history graphic on
another
For graphic, take a look library Core Plot,
quite handy open source plotting framework.
Tutorial available at:
http://www.raywenderlich.com/13269/howto-draw-graphs-with-core-plot-part-1
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7. Architecture
Main power
Non galvanic
adapters
3-phase
xxW
Phone
Wattson
transmitter
~430MHz
Internet
Wattson
receiver
RPi
RJ-45
USB
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Modem
(EP3825)

8. Prerequisites
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Rpi is set up according to latest instructions from community
portal
Wattson device is set up as per instructions provided in sales
package.
Android application development environment available
Basic programming skills on C and Java and familiar with
Android application fundamentals (or iOS development tools
and basics of Objective-C/Xcode IDE)
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9. Tasks for RPi
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Install http-server (like Apache)
Observe IP-address Rpi is getting from
Cable/ADLS-router
Test web server.
Compile OpenWattson on RPi as per its
README.txt
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Find USB-path for connection to Wattson receiver
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Set up Rpi's cron for periodical power reading
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Target to file available on0.02
http-server (/var/www)
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10. Tasks for Cable/ADLS router
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Router provides NAT-addresses not suitable to
Internet. Router has own unique public IP-address
that is dynamic.
For experimental purposes Rpi's server can be
exposed to Internet on port forwarding. This means
that calls on router's port (80) are forwarded to
internal IP where Rpi http server resides.
Above tasks are done on management console of
the router
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11. Tasks for phone app
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Generate Android Application project on app
wizard.
Follow instructions provided earlier to modify your
app for Homescreen Widget
Add http-connection, modify URL based on your
routers public IP
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Use free services like No-IP.com for handling router's
public IP changes
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12. Setup at home
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13. More info needed?
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As normal, there are lot of discussion forums,
wikis, tutorials, …
Presentation and test apps by Ari Lehtola who also
may be able to help.
http://www.linkedin.com/pub/ari-lehtola/3/5ab/58b
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