DorkbotPDX people doing strange things with electricity

After a year of occasional fiddling I am finally happy with the stability and convenience of my sensor network. Some features include:

• Arduino only configuration with off-premise data recording
• Analog, digital, bynase and 1-wire support with scaling and calibration
• Device discovery, labels, documentation and tag-based grouping
• Interactive graphs at time scales from hours to years with decimation and missing-data support

For your browsing pleasure I offer my latest sensor addition, simple ac line voltage monitoring, or browse my whole network.

• http://c2.com/cybords/wiki.cgi?PowerAnalysis
• http://c2.com/~ward/arduino/SensorServer/

I've added a CdS photocell to my network of home temperature sensors. I'm reading it as an analog input using the WebServer Arduino code that goes with the Ethernet shield.

I'm calling this a Twilight Sensor because the sensor range I happened to choose covers that half-light of mornings and evenings. I've cooked up a special FLOT graph that traces equi-temporal contours from day to day.

http://c2.com/~ward/arduino/twilight.cgi?hours=360

If you study this long enough you will see that, yes, the days are getting longer.

My friend Wayne Downer gave me a couple of 1-Wire digital thermometers which I've now hooked up and supplemented with a few more of my own. You and I can both watch the temperatures drop at my house this week using the cool graphics I cooked up with jquery.

You'll find the live data here:

• http://c2.com/~ward/arduino/recent.cgi

I found the SECODER that I spoke about last meeting. It was in the bottom of the wrong junk box with old antenna equipment, not old telephone equipment. My mechanically inclined friends helped me get it working again. I've written a web page describing my original application, Dial-a-Door.

• http://c2.com/~ward/Dial-a-Door

I got out the x-acto knife and built a display stand just for tonight's meeting. This got featured on the AboutUs blog.

• http://blog.aboutus.org/2008/10/27/dial-a-door-technology-to-appear-at-dorkbotpdx-tonight/