🚧 Project Status: Under Active Development & Testing

April 23, 2026 · View on GitHub

Important Notice: This documentation, hardware designs, and firmware are for the pre-release version of the HomeMaster system. All information is preliminary and may contain errors or be subject to change.

Hardware: Modules are currently in the prototyping and testing phase. Final production versions may differ.

Firmware: Firmware is under active development and is considered beta. Features, configurations, and stability are being refined.

Please use this information for evaluation and development purposes only

HOMEMASTER – Modular, Resilient Smart Automation System

Releases: see the latest tagged build on GitHub Releases. Versioning uses YYYY‑MM.
Fully open‑source hardware, firmware, and configuration tools.

🛠️ Hardware Guide

HomeMaster is an industrial‑grade, modular automation system for smart homes, labs, and professional installations. It features:

ESP32‑based PLC controllers (MiniPLC & MicroPLC) — same platform & memory class
A family of smart I/O modules (energy monitoring, lighting, alarms, analog I/O, etc.)
RS‑485 Modbus RTU communication
ESPHome compatibility for Home Assistant
USB‑C & WebConfig UI for driverless configuration

Local resilience: Modules include onboard logic and continue functioning even if the controller or network is offline.

System Architecture

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  %% Classes
  classDef hub fill:#EDEFFB,stroke:#6B72FF,stroke-width:1.2px,color:#111,font-weight:bold;
  classDef big fill:#EDEFFB,stroke:#1F35FF,stroke-width:3px,color:#111,font-weight:bold,font-size:28px;
  classDef mod fill:#FFFffC,stroke:#E0B100,stroke-width:1.2px,color:#111,font-weight:bold,font-size:22px;
  classDef ghost fill:transparent,stroke:transparent,color:transparent;

  %% Double-sized HA and PLC (bigger font + extra line breaks)
  HA["Home Assistant<br/><br/>"]:::big --> PLC["MiniPLC / MicroPLC<br/><br/>"]:::big
  PLC --> RS485[RS-485 Bus]:::hub

  %% Subgraph with taller nodes; extra <br/> increases node height
  subgraph Mods["<br/>"]
    ENM[ENM‑223‑R1<br>⚡ Energy Meter]:::mod
    ALM[ALM‑173‑R1<br>🚨 Alarm I/O]:::mod
    DIM[DIM‑420‑R1<br>💡 AC Dimmer]:::mod
    AIO[AIO‑422‑R1<br>🌡️ Analog I/O]:::mod
    RGB[RGB‑621‑R1<br>🎨 LED Controller]:::mod
    DIO[DIO‑430‑R1<br>🔌 Digital I/O]:::mod
    STR[STR‑3221‑R1<br>💫 Staircase LED]:::mod
    WLD[WLD‑521‑R1<br>💧 Leak Detection]:::mod
    SP1["<br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/>"]:::ghost
  end
  style Mods fill:#FFFFFF,stroke:#E0B100,stroke-width:1.5px, font-weight:bold,font-size:22px

  %% Edges
  RS485 --> ENM
  RS485 --> ALM
  RS485 --> DIM
  RS485 --> AIO
  RS485 --> RGB
  RS485 --> DIO
  RS485 --> STR
  RS485 --> WLD

🎯 Quick Module Selector

💡 Lighting Control → DIM‑420‑R1, RGB‑621‑R1, STR‑3221‑R1
⚡ Measurment & Protecion → ENM‑223‑R1 , WLD‑521‑R1
🚨 Security/Alarms → ALM‑173‑R1
🔌 General I/O → DIO‑430‑R1, AIO‑422‑R1

Controller Comparison

Feature / Use Case	🟢 MiniPLC	🔵 MicroPLC
Size	Full‑width DIN enclosure	Compact DIN enclosure
Onboard I/O	6× Relays, 4× DI, 2× RTD, 2× AI/O, Display, RTC	1× Relay, 1× DI, 1‑Wire, RTC
Connectivity	Ethernet, USB‑C, Wi‑Fi, BLE + Improv	USB‑C, Wi‑Fi, BLE + Improv
Storage	microSD card slot	Internal flash only
Ideal For	Full homes, labs, HVAC/solar, automation pros	Makers, room‑level, modular expansion setups
Power Input	AC/DC wide range or 24 VDC	24 VDC only

Module Overview

Module	Inputs	Outputs	Key Features	Best For
ENM‑223‑R1	3‑Phase CTs	2 Relays	Per‑phase power metrics	Solar, grid monitoring
ALM‑173‑R1	17 DI	3 Relays	AUX power, alarm logic	Security systems
DIM‑420‑R1	4 DI	2 Dimming	Phase‑cut dimming	Lighting control
AIO‑422‑R1	4 AI + 2 RTD	2 AO	0‑10V I/O, PT100/1000	HVAC, sensors
DIO‑430‑R1	4 DI	3 Relays	Override buttons, logic mapping	General control
RGB‑621‑R1	2 DI	5 PWM + 1 Relay	RGB+CCT, smooth fades	Color lighting
STR‑3221‑R1	3 DI	32 LED Channels	Animated sequences	Architectural lighting
WLD‑521‑R1	5 DI + Temp	2 Relays	Leak detection, pulse metering	Safety systems

Recommended Setups

🏠 Starter (Lighting + I/O) — MicroPLC + DIO‑430‑R1 + RGB‑621‑R1
Basic lighting control, wall switch input, RGB strip control
⚡ Energy Monitoring — MicroPLC + ENM‑223‑R1
Track grid power, solar production, or 3‑phase loads
🧪 Professional Lab — MiniPLC + AIO‑422‑R1 + DIO‑430‑R1
Complex automation with analog, temperature, safety logic
💧 Safety & Leak Detection — MicroPLC + WLD‑521‑R1 + ALM‑173‑R1
Leak sensors, alarm inputs, auto‑valve control
🌈 Advanced Lighting — MiniPLC + RGB‑621‑R1 + DIM‑420‑R1 + STR‑3221‑R1
Complete lighting control with scenes and animations

🚀 Quick Start

5‑Minute Setup

Power the controller — ESPHome is pre‑installed on MiniPLC and MicroPLC.
Join Wi‑Fi with Improv — Use Improv (BLE or Serial) to set Wi‑Fi and adopt the device.
Wire RS‑485 — A/B differential pair; 120 Ω termination at both bus ends.
Configure each module — Connect via USB‑C and use WebConfig to set Modbus address and module settings (calibration, mapping, rules).
Open Home Assistant — Add the ESPHome controller; modules appear as entities via the controller config.

⚙️ Configuration

Compatibility

Component	Home Assistant	ESPHome	Standalone
All Modules	✅ Full	✅ Native	✅ Basic
MiniPLC	✅ Full	✅ Pre‑installed	✅ Full
MicroPLC	✅ Full	✅ Pre‑installed	✅ Basic

Controller Setup

All HomeMaster controllers come with ESPHome pre‑installed and support Improv onboarding:

Power on the controller
Connect via improv-wifi.com (BLE or USB)
Enter Wi‑Fi credentials
Appears in ESPHome Dashboard & Home Assistant

Module Configuration (WebConfig)

Each module includes USB WebConfig — no drivers needed:

Set Modbus address and baud rate
Configure relay behavior and input mappings
Perform calibration and live diagnostics
Adjust alarm thresholds and LED modes

💡 WebConfig works in Chrome/Edge — just plug in USB‑C and click Connect

Networking

RS‑485 Modbus: 19200 8N1 (default), 120 Ω termination required
Wi‑Fi: Both controllers; Improv onboarding
Ethernet: MiniPLC only for stable connections
USB‑C: Configuration and programming

🔧 Advanced

Firmware Development

All HomeMaster controllers and modules support firmware customization via USB‑C.

ESPHome YAML (pre-installed on controllers)
Arduino IDE (both ESP32 and RP2040/RP2350)
PlatformIO (cross-platform)
MicroPython (via Thonny)
ESP-IDF (for ESP32-based controllers)
Pico SDK / CircuitPython (for RP2350-based modules)

USB‑C Developer Flashing

Both controllers and modules support easy flashing and auto-reset via USB‑C, with no need to press BOOT or RESET buttons.

ESP32-based controllers (MiniPLC, MicroPLC): programmable using Arduino IDE, PlatformIO, ESP-IDF, or ESPHome Dashboard.
RP2350-based modules: support drag‑and‑drop UF2 flashing and tools from the RP2040 ecosystem (e.g., Pico SDK, CircuitPython).

⚠️ Note: All controllers and modules ship with pre-installed firmware.

Controllers are ESPHome-ready and appear in Home Assistant.

Modules are fully functional out-of-the-box and configurable via the WebConfig Tool.

Flashing is only required for advanced users who want to replace default firmware.

Arduino & PlatformIO Notes

Clone the firmware repository
Use the provided default_xxx.ino sketches per module or controller
Add libraries as needed:
ModbusSerial, LittleFS, Arduino_JSON, SimpleWebSerial

Home Assistant Example (ESPHome)

# Example ESPHome configuration for Alarm Module
uart:
  id: uart_modbus
  tx_pin: 17
  rx_pin: 16
  baud_rate: 19200
  parity: NONE
  stop_bits: 1

modbus:
  id: modbus_bus
  uart_id: uart_modbus

# ---------- Pull ALM Modbus entities from GitHub ----------
packages:

  alm1:
    url: https://github.com/isystemsautomation/homemaster-dev
    ref: main
    files:
      - path: ALM-173-R1/Firmware/default_alm_173_r1_plc/default_alm_173_r1_plc.yaml

📚 Resources

🎓 Learning & Community

🌐 Official Support: https://home-master.eu/support
🧠 Hackster.io: Projects & tutorials
🎥 YouTube: Video guides
💬 Reddit: r/HomeMaster
📷 Instagram: @home_master.eu

⚠️ Safety Information

Electrical Safety

Only trained personnel should install or service modules
Disconnect all power before wiring
Follow local electrical codes and standards

Installation

Mount on 35 mm DIN rails in protective enclosures
Separate low‑voltage and high‑voltage wiring
Avoid moisture, chemicals, and extreme temperatures

Device‑specific Warnings

Connect PE/N properly for metering modules
Use correct CTs (1 V or 333 mV) — never connect 5 A CTs directly
Avoid reverse polarity on RS‑485 lines

License

Licensing

This project uses a hybrid licensing model.

Hardware

Hardware designs (schematics, PCB layouts, BOMs) are licensed under: CERN-OHL-W v2

Firmware & ESPHome Integration

All firmware, ESPHome configurations, and software components are licensed under: MIT License

This ensures full compatibility with ESPHome and Home Assistant while protecting hardware designs.

See LICENSE files in each directory for full terms.

🔄 Version Info

Current: HomeMaster 2024.12+ series
Check: Releases page for version‑specific notes