[g_hajdukiewicz]

Thanks for asking! I can explain you how the lighting unit works since I was taking part in designing it (better than nothing :) ). Since we didn't have enough GPIOs on the Raspberry which is controlling the lights, we used a GPIO expanders (MCP23017 https://goo.gl/S4i9Gw). RPi sends commands over I2C interface to switch their outputs on and off. MCPs outputs are driving optocouplers (on the same PCBs designed by us) to provide a proper level of isolation. Then the optocouplers' outputs drive the relays working in a "stair case" configuration with analog switches on the walls (see a my comment above and here https://goo.gl/sJw9F1). All the "low-level" software is written in python using ready to go libraries and exposing API to a web-app which is basically a user interface for the system. If you need more details, just shoot!

[SpikedCola]

Love your use of wire duct to keep things organized, and small attention to detail like ferrules on each wire going into the terminal blocks.

To my eyes this shows really you care about what you build.

Nice job!

[g_hajdukiewicz]

Many thanks! It's always good to design your system like that. The same with software :) Makes it easier to maintain.