In this chapter, we built a thermostat device. We looked at thermistors, and you learned how to set up an Ethernet connection. To control our thermostat, we wrote an Arduino sketch, uploaded it to the microcontroller, and then tested it with a fan plugged into the mains electricity.

Finally, we reviewed some steps to expand the device so that it can accommodate an LCD screen and potentiometer to change the observed temperature.

Next, we will look at building a database to store the values returned from our thermostat. This will be done in our first project using the Raspberry Pi.