Congratulations! You have finished building a web-based thermostat and creating software to control it.
Now that we have the basics in place, we can add extra features and connect the device to our home heating system, fish tank, or something similar.
The following projects are optional. With the thermostat device you have built, you can continue to follow the examples in the coming chapters, skipping the following section if you wish.
You can always revisit these projects at a later date.
Your next step will be to attach the thermostat to another electrical system you wish to control, for example, a heating system or fish tank. Some thermostats handle multiple systems such as heating and cooling, and if you wish to replicate this functionality, you will need to add more relays to your device and expand the sketch code to support switching multiple relays on and off. The thermostat we built works with a two-wire system...