Engineering Seamless Complexity

It’s all starting to fall into place; the arduous research, sifting through documentation, and good old trial and error are paying off in spades. The house is coming alive, becoming a part of our daily lives. We’re in the future, and it’s free and liberating.

I’ve been building my smart home on open standards and technology, it’s self-hosted and doesn’t cost anything but a few watts.

This post describes a vertical slice of one single automation within my home and an appreciation of the many layers of free and open-source software.

The goal is simple enough, I would like the lights to turn on when a movie is paused, and off again when the movie is resumed.

It’s fair to say that Home Assistant is the conductor, but it’s not without its orchestra - Within the space of ~100ms this elegant symphony begins and concludes.

Our instruments are: Infrared, HDMI-CEC, USB, Kodi, HTTP, Home Assistant, Zigbee.

Here’s how it all fits together:

The Flow

Breakdown

1. The TV remote sends an infrared signal to the TV when the pause button is pushed.
2. The TV, using HDMI-CEC, communicates with the ONKYO AV RECEIVER.
3. The AV RECEIVER, also using HDMI-CEC, communicates with the Pulse Eight HDMI-CEC Adapter.
4. The Pulse Eight HDMI-CEC Adapter connects to Kodi running on Fedora/Linux via USB.
5. Kodi, using libCEC to listen to HDMI-CEC events pauses the media playback.
6. Home Assistant running on HAOS listens for events via HTTP.
7. Home Assistant sends an “ON 0x0004 Zigbee” command to the Zigbee Mesh (ZBC).
8. Zigbee Mesh forwards the “ON 0x0004 Zigbee” command to the Zigbee Light group (ZG).
9. Zigbee Light group (ZG) controls Lamp 1, Lamp 2, and Lamp 3 by sending “ON” commands.

Conclusion

The appreciation I have for modern technology and the free and open-source community is immense. This automation, while but a trivial convenience, showcases years of volunteer work, and interoperation between a variety of technologies, and what’s most important in my opinion, is that as hackers, tinkerers, and engineers we can stand on the shoulders of giants and achieve amazing things together - Even if that thing, is something superfluous like automating your lights..

I hope you feel as inspired as I do and can use this as an inspiration for how you appreciate and approach your home automation.

Technology Used:

• Pulse Eight
  • HDMI-CEC Adapter
  • libCEC
• Home Assistant
  • ZHA Integration
  • Kodi Integration
• Kodi
  • CEC