Wiring Scheme

Pi-Home - principle wiring diagram

System Description

The core of the smart home installation is the Raspberry Pi (RPi) board, which runs the central automation software — OpenHAB or Home Assistant. For details on installing OpenHAB on RPi, refer to the How-To section.

The RPi is connected to Arduino Mega boards via USB, which also serves as the programming interface. Communication between the RPi and Arduino boards occurs over MQTT — a lightweight, protected, publish/subscribe messaging protocol ideal for home automation. The entire system is networked via local LAN and can be extended with MQTT-compatible devices or popular wireless standards like Z-Wave or Zigbee and many others.

Main features:

Controlling high power circuits (lights, sockets, pumps, electric heaters)

We are using combination of Arduino compatible SSR relay board 230V/2A connected with standard robust installation relay (230V/20A) in separate hig power distribution board. This setup ensures safe and reliable switching of high-power devices.

Controlling low power circuits ~ 200W (ventilation, heat valves, blinds)

You can controll low-power devices directly with Arduino relay board 230V/2A SSR. Boards are available from single output up to eight outputs.

LED lights

Due to very high current during first several miliseconds of 230V LED lights, we recommend to use Arduino relay board together with robust relay - same as sockets, pums. See first option.

Sensors

Sensors (temperature, humidity, motion, etc.) are typically wired using UTP cables, terminated in the distribution board on KRONE modules. 

• Each cable splits into DATA / GND / 5V lines
• Connected directly to Arduino Mega, the sensors run on simple sketches (firmware)
• Data is sent to central unit via MQTT

This setup supports a wide range of Arduino-compatible sensors, ensuring low hardware cost, maximum customizability, and flexibility in sensor enclosure design.

Wireless

For apartments or retrofit installations, OpenHAB and Home Assistant supports integration with Shelly and various Z-Wave, Zigbee, and other wireless protocols.

• Devices are installed locally where needed — just before the device being controlled
• OpenHAB’s or Home Assistant rule engine allows for intuitive "if-this-then-that" logic.
• We have extensive experience with Shelly devices, offering great reliability on local WiFi network and communicate via MQTT

Detail scheme for PiHome Pro model house (see How To section):