This blog post explains my work as R&D Manager / Project Manager between 2013-2018, which I designed 1st android / Linux Home Automation touch panels developed & manufactured in Turkey.
Touch Panels used in Home Automation market are usually embedded devices, with Android/Linux OS and custom hardware interfaces such as KNX.
KNX is an open standard (see EN 50090, ISO/IEC 14543) for commercial and domestic building automation. 
Figure 1 Home Automation Touch panels
TouchPanels used in Home Automation market provides multiple functionalities, such as:
- Home Automation Visualization - Home Automation Server Device - Mobile App gateway - SIP Intercom Client - Site Management Client - Misc. (Weather, News, RSS…etc.)
Figure 2 Typical Infrastructure for Home Automation for an apartment
These devices are usually embedded devices, with Android/Linux OS. Since they are used in Home Automation networks, they need to have corresponding hardware interfaces and software built-in.
In Europe / Middle East markets, most popular home automation bus is still a wired one: KNX. KNX Association has more than 400 manufacturers with thousands of devices which are compatible with KNX protocol.
Design & Development of such complex devices needed expertise on multiple disciplines, such as:
• Industrial / Mechanical Design • PCB Schematic / Layout Design • Android / Linux Board Bring up • User Space App Design
For this case, I will not go deeper, but provide photos, and some high-level design documents:
Figure 3 Interra5 Mechanical Design
Figure 4 Interra4 and Interra5 PCBA
I personally ported Android AOSP and Linux Debian 7/8 to all that hardware, depending on the use-cases. Since it is a wide topic, I will not go deeper.
I also lead software team to develop user space apps for touch panels, as well as mobile apps as seen in below photos:
Figure 5 Home Automation Apps
During my work as R&D / Project Manager, I developed 5 generations of Android / Linux Touch panels to be used in Home Automation projects with KNX Protocol.
Hundreds of thousands of private homes / apartments / buildings / offices are using these products with a reliable KNX bus connection.