Smart Home Build Guides — System Design & Engineering Tutorials

ESPHome is a firmware system that runs on ESP32 and ESP8266 devices, defining their behavior through simple YAML configuration files. Home Assistant is a smart home platform that runs on a server (Raspberry Pi, mini-PC, or NAS) and acts as the central brain that connects all your devices, automations, and dashboards. They work together: ESPHome creates smart devices with local control, Home Assistant orchestrates them into a coordinated smart home. HomeMaster modules ship with ESPHome firmware out of the box, ready to integrate with Home Assistant via the native API. You don't need to choose — you use both.

For basic installation — no. HomeMaster modules mount on a standard DIN-rail in your electrical panel, connect via screw terminals, and work with Home Assistant out of the box using included ESPHome configurations. For advanced customization (writing automations, modifying YAML, adding custom logic) — basic familiarity with YAML files and Home Assistant interface helps. We provide ready-to-use configurations for every module on our GitHub repository, so you can start immediately. For installations involving 230V mains wiring, we recommend a certified electrician.

Start with MiniPLC if you want a self-contained smart home controller with built-in 6 relays, I/O ports, temperature sensing, display, and integrated AC/DC power supply — it's a complete solution out of the box. Start with MicroPLC if you're building a modular system where the controller manages multiple expansion modules over RS-485 Modbus and you want to scale gradually — it's smaller, more cost-effective, and ideal as the brain of a multi-module installation. Both run ESPHome and integrate natively with Home Assistant. Most installations end up using MicroPLC + 2-5 expansion modules for full home coverage.

Yes — fully. HomeMaster is built on a local-first architecture with no cloud dependency. Each module runs its own logic locally, communicating with the controller via wired RS-485 Modbus. The controller (MiniPLC or MicroPLC) communicates with Home Assistant on your local network. Lighting, heating, security, and energy monitoring all continue working without internet — you only need internet for remote access (e.g., controlling your home from outside) and Home Assistant updates. Even if your router fails, the controller and modules keep operating with their built-in fail-safe logic.

Yes. Every HomeMaster module ships with ESPHome firmware that uses Home Assistant's native API. After installation, modules appear automatically in Home Assistant via mDNS auto-discovery. You don't need to write integration code, install custom components, or use MQTT brokers — just power up the module on your network and it shows up in Home Assistant ready to use. We provide ready-to-use YAML configurations for each module on our GitHub repository, and our online configurators help you customize behavior without writing code.

Modules that operate on low voltage (DC, sensor inputs, RS-485) can typically be installed yourself if you're comfortable with basic electrical work. For modules connecting to 230V AC mains (DIM-420 dimmer, MiniPLC AC input, AC-switching relays in DIO-430), we strongly recommend hiring a certified electrician — both for safety and to comply with EU electrical regulations. Most installations involve at least some 230V work since that's what controls your lighting and heating. We provide detailed wiring diagrams in every product manual, but the actual mains connection should be done by a qualified professional.

Standard on/off thermostats simply tell the boiler «on» or «off» — the boiler then runs at maximum power until target temperature is reached, leading to overshoot, energy waste, and noisy cycles. OpenTherm is a digital communication protocol that lets the thermostat communicate continuously with the boiler — adjusting flame modulation, water temperature, and operating mode in real time. This results in 10-30% energy savings, more comfortable temperature stability, longer boiler lifespan, and quieter operation. Our OpenTherm Gateway module brings this protocol into Home Assistant with full local control — no proprietary thermostat needed.

All 11 HomeMaster modules are CE marked. ISYSTEMS AUTOMATION S.R.L. (HomeMaster® brand) holds the technical documentation and a signed EU Declaration of Conformity (DoC) for each module, available for download on every product page. Compliance covers the EMC Directive 2014/30/EU, the Low Voltage Directive 2014/35/EU (EN 62368-1) and the RoHS Directive 2011/65/EU.

Yes — fully. All HomeMaster firmware (ESPHome YAML configurations) and hardware schematics are publicly available on our GitHub repository under permissive open-source licenses. You can fork, modify, and customize anything. We believe in zero vendor lock-in: your smart home should outlive the company that made the hardware. If we ever stop developing new products, the existing modules remain fully functional, fully documented, and fully modifiable. This is the opposite of cloud-locked smart home brands where the device becomes a paperweight when the company sunsets the product.

Yes. HomeMaster runs on a local-first architecture with no cloud servers required for operation. All firmware and schematics are open-source on GitHub. Modules use standard ESPHome firmware that the global community maintains. They communicate with Home Assistant via standard Modbus and ESPHome APIs — both are widely-supported open standards. If we disappear tomorrow, your modules keep working forever, you can still flash new firmware, and you have the full schematics if you ever need to repair or modify hardware. This is the deliberate design principle — not an accidental outcome.

DIN-rail mounting is the European standard for electrical panels — every modern home distribution board has DIN-rail slots where circuit breakers, RCDs, and other protective devices live. Mounting smart home modules on the same rail means: clean centralized installation, professional appearance, easy maintenance access, easier wiring with proper cable management, and visible status LEDs for diagnostics. Wall-mount smart switches scattered throughout a home become a nightmare to maintain — you have to unscrew faceplates and squeeze inside walls. DIN-rail centralizes everything, making your smart home maintainable for the next 20 years.

HomeMaster modules are designed for 10+ year operational lifespan, using industrial-grade components (electrolytic capacitors rated for high temperature, opto-isolated inputs, proper transient protection). All modules carry a 2-year manufacturer warranty per EU regulations, with extended warranty options available for certified installer projects. Because firmware and schematics are open-source, the practical lifespan extends well beyond the warranty — you can repair, modify, or replace components long after standard warranty expires. We also publish a public firmware changelog and continue supporting older modules with security updates.

Yes — HomeMaster modules integrate seamlessly with any Home Assistant installation (Home Assistant OS, Container, Supervised, or Core). They use Home Assistant's native ESPHome integration which is built-in and requires no additional setup. After connecting a HomeMaster module to your network, it appears in Home Assistant's «Discovered devices» section automatically. You can then add it with one click and start using it in automations, dashboards, and scripts. They coexist with any other Home Assistant integrations you have — Zigbee, Z-Wave, MQTT devices, cloud integrations — all in one unified system. No conflict, no migration needed.