When [William’s] thermostat died, he wanted an upgrade. He found a few off-the-shelf Internet enabled thermostats, but they were all very expensive. He knew he could build his own for a fract… ...

A wifi controlled thermostat is fairly easy to make with an Arduino. There are a ton of sample projects that you can peruse if you Google "Arduino thermostat".

But with a little sweat-equity you can fix it with this Arduino thermostat and temperature display. We’ll stipulate that an Arduino may be overkill for this application and that microcontrollers ...

Four engineers from Spark have pooled their skills and resources to create a new open source smart thermostat based on Arduino using $70 of components.