This is the final part of "How to Build Your Own $3.2bln Nest Startup Using Java SE Embedded Technology". You've followed along and now have your Raspberry Pi connected to your home thermostat to control your heating, cooling, and fan controls of your furnace and A/C. You also ran through a Java diagnostic app that cycled through the heating, cooling, and fan relays to make sure you are able to turn on and off the controls programmatically. Very nice.
Now, it's up to you to create your user interface and control software. Remember to utilize the Web since you are connected via Wi-Fi to your home wireless network. Just make sure to use the proper HTTPS connection to any server and check for proper authorization for every connection. Using certificate based authentication is best, but that's a topic that's outside the scope of this series.
For the UI, just make sure Jetty is installed on your RPi. Jetty is a Java SE Embedded based Web server to run your UI on your local LCD touchscreen.
sudo apt-get install jetty
Now, when you boot up your Raspberry Pi, just configure your boot-up to bring up the Midori Web browser on the Ada Fruit TFT LCD screen pointing to your local Jetty Web server and your UI page to your software.
That should get you started on your way to building your own home thermostat control based on Java SE Embedded technology. Not too shabby!
Good luck on finishing out your project! Hope this was useful in getting you on your way to creating your own Nest startup.