[mos1]

I have a geothermal HVAC system, and it's not very well designed. If the loop temperatures drop below a certain point it becomes ineffective, and I need to manually switch to a secondary heat source.

In a single afternoon, I was able to hook some one-wire sensors into the loops, attach them to a widget that made the sensor data available via IP, write a daemon that monitors the temperature, and then automatically notifies the IP-enabled thermostat to flip over to secondary heat if the loops go below effective temperatures, and to flip back when they recover.

The next day, I made it so the loop temperatures were recorded and graphed, and that I receive an SMS alert if there's a complete HVAC failure (loops too cold + secondary heat failure).

That was some awesome tinkering.

[DaniFong]

Impressive.

It might be very interesting to chat.

I'd appreciate if you dropped me an email to dfong <a.t> lightsailenergy.com :-)

[joshu]

Same. What was the widget? Been thinking of hiring someone to do some board layout work to build these.

[mos1]

It's just an off-the-shelf Barix Barionet 50. It does the job well, and only draws a watt or two (literally).

Not terribly impressive, but $150 worth of my own work wouldn't have been able to drop the power usage to those levels.