homemaster-dev

🚧 Project Status: Under Active Development & Testing

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.

Please use this information for evaluation and development purposes only. Check the Releases page for the latest stable versions and updates.

Firmware Version: 2025-09 snapshot

Firmware Version Modbus License

ENM-223-R1 — 3-Phase Power Metering & I/O Module

HOMEMASTER – Modular control. Custom logic.

MODULE photo

Module Description

The ENM-223-R1 is a configurable smart I/O module designed for 3-phase power quality and energy metering.
It includes 3 voltage inputs, 3 current channels, 2 relays, and optional 4 buttons / 4 LEDs, with configuration via WebConfig using USB-C (Web Serial).
It connects over RS-485 (Modbus RTU) to a MicroPLC/MiniPLC, enabling use in energy monitoring, automation, and smart building applications.

Table of Contents


1. Introduction

1.1 Overview of the ENM‑223‑R1 Module ⚡

The ENM‑223‑R1 is a modular 3‑phase energy metering + I/O device for power monitoring, automation, and local control. It features 3 voltage channels (L1/L2/L3‑N), 3 current channels (external CTs), 2 SPDT relays, 4 user LEDs, and 4 buttons—all driven by an RP2350 MCU with QSPI flash and a dedicated ATM90E32AS metering IC.

It integrates with MiniPLC/MicroPLC controllers or any Modbus RTU master over RS‑485, and it’s configured in‑browser via USB‑C Web Serial (no drivers). Typical uses include energy dashboards, demand response, alarm‑driven relay control, and building automation. Defaults ship as Modbus address 3 @ 19200 8N1 (changeable in WebConfig).

Quick device flow:
Wire Lx/N/PE + CTs → set address/baud in WebConfig → calibrate gains/offsets → define alarms per L1/L2/L3/Totals → map relays/LEDs/buttons → connect RS‑485 A/B (and GND if separate PSUs) → poll via Modbus.

1.2 Features & Architecture

Core Capabilities

Subsystem Qty Description
Voltage Inputs 3 L1/L2/L3‑N measurement (divider network on FieldBoard) feeding ATM90E32AS
Current Inputs 3 Differential CT inputs (IAP/IAN, IBP/IBN, ICP/ICN) with filtering/burdens
Relays 2 SPDT dry contacts (NO/NC); opto‑driven; alarm‑ or Modbus‑controlled
LEDs 4 User LEDs; sources: overrides/alarms/warnings/events; steady or blink
Buttons 4 User actions (toggle relays/LEDs, overrides, acks) with live state feedback
Metering & Energy — ATM90E32AS: Urms/Irms, P/Q/S, PF, angle, freq; energy kWh/kvarh/kVAh (phase & totals)
Config UI Web Serial In‑browser WebConfig over USB‑C (Chrome/Edge); live meter, calibration, alarms, relays, LEDs, buttons
Modbus RTU RS‑485 Multi‑drop slave; address 1…255; baud 9600–115200 (default 19200 8N1)
MCU RP2350 + QSPI Dual‑core MCU, native USB, external W25Q32 flash; RS‑485 via MAX485 transceiver
Power 24 VDC Buck to 5 V → 3.3 V LDO; isolated analog domain via B0505S DC‑DC + ISO7761
Protection TVS, PTC, fuses Surge/ESD on USB & RS‑485; resettable fuses on field I/O; reverse‑polarity protection

1.3 System Role & Communication 🍰

The ENM‑223‑R1 is a smart Modbus RTU slave. It executes local alarm logic (thresholds & acks) and mirrors states/values to a PLC or SCADA via registers/coils. Configuration (meter options, calibration, relay/LED logic, button actions, Modbus address/baud) is done via USB‑C WebConfig, stored to non‑volatile memory.

Role Description
System Position Expansion meter+I/O on the RS‑485 trunk (A/B/GND)
Master Controller MiniPLC / MicroPLC or any third‑party Modbus RTU master (polling)
Address / Baud Configurable 1…255 / 9600–115200; factory default: ID 3 @ 19200 8N1
Bus Type RS‑485 half‑duplex; termination/bias per bus rules; share GND if separate PSUs
USB‑C Port Setup/diagnostics via Chromium browser (Web Serial); native USB D+/D− to MCU
Default Modbus ID 3 (change in WebConfig)
Daisy‑Chaining Multi‑drop on shared A/B; ensure unique IDs and end‑of‑line termination

Note: The UI exposes per‑channel Alarm / Warning / Event with min/max thresholds and Ack required option; relays can follow selected alarm kinds or be Modbus‑controlled. Buttons can toggle/override relays; LEDs reflect overrides or alarm states.

2. Use Cases

This section outlines practical application examples for the ENM‑223‑R1 module. Each use case includes a functional goal and a clear configuration procedure using the WebConfig tool and/or Modbus RTU integration.

These templates are applicable in energy management, automation, industrial control, and building infrastructure deployments.

2.1 Overcurrent Alarm with Manual Reset

Purpose: Activate Relay 1 when current exceeds a configured threshold and hold it until manually acknowledged.

Configuration:

2.2 Manual Override for Load Control

Purpose: Allow field operators to override Relay 2 using a button, regardless of Modbus or automation control.

Configuration:

Holding the button for 3 seconds enters override mode. A short press toggles the relay. Holding again exits override mode.

2.3 Environmental Voltage/Frequency Alarm with Auto-Clear

Purpose: Detect power quality faults (sag/swell or freq drift), activate Relay 1 as an output, and auto-reset when back in range.

Configuration:

2.4 Staged Load Shedding via Modbus Scenes

Purpose: Use a controller to shed non-critical loads as power consumption increases.

Configuration:

Ideal for HVAC or lighting where priority-based power shedding is needed.

Summary Table

Use Case Feature Used Reset Method Relay Mode
Overcurrent Alarm + Ack Alarms, Ack, Relay 1 Manual (Ack) Alarm Controlled
Manual Override via Button Button override, LED Button toggle Modbus Controlled
Voltage/Frequency Fault Auto-Reset Alarm (no ack), Relay Auto (value returns) Alarm Controlled
Load Shedding (Staged Scenes) PLC Modbus, Relay 1 & 2 PLC-controlled Modbus Controlled

🛠 All parameters are configurable via USB‑C WebConfig. Modbus control assumes master-side logic (PLC, SCADA, or MicroPLC/MiniPLC).

3. Safety Information

These safety guidelines apply to the ENM‑223‑R1 3‑phase metering and I/O module. Ignoring them may result in equipment damage, system failure, or personal injury.

⚠️ Mixed Voltage Domains — This device contains both SELV (e.g., 24 V DC, RS‑485, USB) and non-SELV mains inputs (85–265 V AC). Proper isolation, wiring, and grounding are required. Never connect SELV and mains GND together.

3.1 General Requirements

Requirement Detail
Qualified Personnel Installation and servicing must be done by qualified personnel familiar with high-voltage and SELV control systems.
Power Isolation Disconnect both 24 V DC and voltage inputs (Lx/N) before servicing. Use lockout/tagout where applicable.
Environmental Limits Mount in a clean, sealed enclosure. Avoid condensation, conductive dust, or vibration.
Grounding Bond the panel to PE. Wire PE and N to the module. Never bridge GND_ISO to logic GND.
Voltage Compliance CT inputs: 1 V or 333 mV RMS only. Voltage inputs: 85–265 V AC. Use upstream fusing and surge protection.

3.2 Installation Practices

Task Guidance
ESD Protection Handle only by the case. Use antistatic wrist strap and surface when the board is exposed.
DIN Rail Mounting Mount securely on 35 mm DIN rail inside an IP-rated cabinet. Allow cable slack for strain relief.
Wiring Use correct gauge wire and torque terminal screws. Separate relay, CT, and RS‑485 wiring.
Isolation Domains Respect isolation: Do not bridge GND_ISO to GND. Keep analog and logic grounds isolated.
Commissioning Before power-up, verify voltage wiring, CT polarity, RS‑485 A/B orientation, and relay COM/NO/NC routing.

3.3 I/O & Interface Warnings

⚡ Power

Area Warning
24 V DC Input Use a clean, fused SELV power source. Reverse polarity is protected but may disable the module.
Voltage Input Connect L1/L2/L3/N/PE only within rated range (85–265 V AC). Use circuit protection upstream.
Sensor Domain Use CTs with 1 V or 333 mV RMS output. Never apply 5 A directly. Observe polarity and shielding.

🧲 Inputs & Relays

Area Warning
CT Inputs Accept only voltage-output CTs. Reversing polarity may affect power sign. Use GND_ISO reference.
Relay Outputs Dry contacts only. Rated: 5 A @ 250 VAC or 30 VDC. Use snubber (RC/TVS) for inductive loads.

🖧 Communication & USB

Area Warning
RS‑485 Bus Use twisted pair. Terminate at both ends. Match A/B polarity. Share GND if powered from different PSUs.
USB-C (Front) For setup only. Not for permanent field connection. Disconnect during storms or long idle periods.

🎛 Front Panel

Area Warning
Buttons & LEDs Can override relays or trigger alarms. Use firmware settings or lockout for safety-critical installs.

🛡 Shielding & EMC

Area Recommendation
Cable Shields Terminate at one side only (preferably PLC/controller). Route away from VFDs and high-voltage cabling.

✅ Pre‑Power Checklist

🧷 Tip: In single-phase installations, energize L1 and tie L2/L3 → N to prevent phantom voltages.

4. Installation & Quick Start

The ENM‑223‑R1 connects to your system over RS‑485 (Modbus RTU) and supports configuration via USB‑C WebConfig. Setup involves:
1) Physical wiring, 2) Digital setup (WebConfig → Modbus or PLC/ESPHome control).

4.1 What You Need

Category Item / Notes
Hardware ENM‑223‑R1 module: DIN-rail, 3 voltage channels, 3 CTs, 2 relays, 4 buttons, 4 LEDs, RS‑485, USB‑C
Controller MicroPLC, MiniPLC, or any Modbus RTU master
24 VDC Power (SELV) Regulated 24 V DC @ ~100–200 mA
RS‑485 Cable Twisted pair for A/B + COM/GND; external 120 Ω end-termination
USB‑C Cable For WebConfig setup via Chromium browser (Chrome/Edge)
Software Web browser (Web Serial enabled), ConfigToolPage.html
Field Wiring L1/L2/L3/N/PE → voltage inputs, CT1/2/3 → external CTs
Load Wiring Relay outputs (NO/COM/NC); observe relay max rating and use snubbers on inductive loads
Isolation Domains GND (logic) ≠ GND_ISO (metering); never bond these directly
Tools Torque screwdriver, ferrules, USB-capable PC, 120 Ω terminators if needed

Quick Path
① Mount → ② wire 24 VDC + RS‑485 (A/B/COM) → ③ connect USB‑C → ④ launch WebConfig →
Set Address/Baud → assign Inputs/Relays/LEDs → confirm data → ⑤ disconnect USB → hand control to Modbus master.

4.2 Power

The ENM‑223‑R1 uses 24 V DC input for its interface domain and internally isolates metering circuits.

4.2.1 Sensor Isolation

Only voltage inputs (Lx-N) and CTs connect to the isolated domain.

4.2.2 Power Tips

4.3 Networking & Communication

4.3.1 RS‑485 (Modbus RTU)

Physical

Terminals Description
A, B Differential signal pair (twisted/shielded)
COM/GND Logic reference (tie GNDs if on separate supplies)

Cable & Topology

Defaults

Setting Value
Modbus Address 3
Baud Rate 19200
Format 8N1
Address Range 1–247

🧷 Reversed A/B will cause CRC errors — check if no response.

4.3.2 USB‑C (WebConfig)

Purpose: Web-based configuration tool over native USB Serial. Supports:

Steps

  1. Connect USB‑C to PC (Chrome/Edge)
  2. Open tools/ConfigToolPage.html
  3. Click Connect, select ENM serial port
  4. Configure settings: address, relays, LEDs, alarms, calibration
  5. Click Save & Disconnect when finished

⚠️ If Connect is greyed out: check browser support, OS permissions, and close any other apps using the port.

4.4 Installation & Wiring

Use diagrams and explain:

4.5 Software & UI Configuration

The ENM‑223‑R1 is configured using the browser‑based WebConfig Tool
(tools/ConfigToolPage.html) over USB‑C.
No drivers or software installation is required — configuration happens directly via Web Serial API (Chrome/Edge).

1) Modbus Setup (Address & Baud)

WebConfig — Modbus address & baud

2) Meter Options & Calibration

Meter options and calibration

Meter Options

Calibration (per phase A/B/C)

3) Alarms / Inputs (Per‑Channel Rules)

Alarms per channel

The ENM has 4 measurement channels: L1, L2, L3, and Totals.

Each channel supports:

You can configure:

Acknowledgment:

💡 ENM has no digital inputs (DIs). These rules are “virtual inputs” based on real-time metering data.

4) Relay Logic Modes

Relay logic options

Each of the two onboard SPDT relays can be configured independently.

Options:

Setting Description
Enabled at Power-On Relay state after boot (on/off)
Inverted (active-low) Affects both relays; sets low = ON
Mode None, Modbus Controlled, or Alarm Controlled
Toggle Manually toggle the relay from the UI
Alarm Control Options Select Channel: L1–L3 or Totals and which kinds to follow: Alarm / Warning / Event

In Alarm Controlled mode, direct Modbus writes may be blocked when an alarm is active.

5) Button & LED Mapping

Buttons and LED mapping

Buttons (1–4)

Each button can be mapped to:

User LEDs (1–4)

Each LED has:

💡 Use Override R1 as LED 1 source to give a clear local override status.

6) Live Meter & Energies

Live meter values

Live Meter View:

Energies:

Use this screen to verify CT orientation, load phase mapping, and live alarm behavior during commissioning.

4.6 Getting Started (3 Phases)

Phase 1 — Wire

👉 See: Installation & Quick Start

Phase 2 — Configure (WebConfig)

👉 See: WebConfig UI

Phase 3 — Integrate (Controller)

👉 See: Modbus RTU Communication & Integration Guide

✅ Verify

Area What to Check
LEDs PWR = ON; TX/RX = blink during comms
Voltage L1–L3 read ~230 V (or phase-neutral voltage)
Current  

5. ENM-223-R1 — Technical Specification

5.1 Diagrams & Pinouts

System Diagram
System Block Diagram 		MCU Pinout
RP2350 MCU Pinout
Field Board Terminal Map
Field Board Layout 		MCU Board Layout
MCU Board Layout

💡 Note: Pinouts correspond to hardware revision R1. Terminals are pluggable 5.08 mm pitch (26–12 AWG, torque 0.5–0.6 Nm).

5.2 I/O Summary

Interface Qty Description
Voltage Inputs 3 L1 / L2 / L3–N, 85–265 V AC via precision divider to ATM90E32AS metering IC
Current Inputs 3 CT1–CT3, external 333 mV / 1 V RMS split-core CTs
Relay Outputs 2 SPDT dry contact, HF115F series, opto-driven; 5 A @ 250 VAC / 30 VDC (module limit)
User LEDs 4 Assignable status / override indicators (GPIO18–21)
Buttons 4 Momentary tactile switches (GPIO22–25)
RS-485 1 A/B/COM, Modbus RTU, MAX485 transceiver
USB-C 1 Native USB 2.0 (Web Serial + firmware flashing), ESD-protected
Power Input 1 24 V DC (22–28 V) logic supply, reverse & surge protected

5.3 Absolute Electrical Specifications

Parameter Min Typ Max Unit Notes
Supply Voltage (V+) 22 24 28 V DC SELV; reverse / surge protected input
Power Consumption – 1.85 3.0 W Module only, no external loads
Logic Rails – 3.3 / 5 – V Buck (AP64501) + LDO (AMS1117-3.3)
Isolated Sensor Rails – +12 / +5 – V From B0505S-1WR3 isolated DC-DC
Voltage Inputs 85 – 265 V AC Divided to ATM90E32AS AFE
Current Inputs – 1 / 0.333 – V RMS External CTs
Relay Outputs – – 5 A SPDT; 250 VAC/30 VDC; varistor + snubber recommended
RS-485 Bus – 115.2 – kbps MAX485; short-circuit limited; fail-safe bias
USB-C Port – 5 5.25 V DC Native USB; ESD protected
Operating Temp. 0 – 40 °C ≤ 95 % RH non-condensing
Isolation (DC-DC) – 1.5 3.0 kV DC Metering domain via B0505S-1WR3
Isolation (Digital) – 5.0 – kV RMS ISO7761 6-ch isolator between MCU ↔ AFE

🧩 Values validated from schematics and manufacturer datasheets for ATM90E32AS, ISO7761, B0505S-1WR3, HF115F, AP64501.

5.4 Connector / Terminal Map (Field Side)

Block / Label Pin(s) (left→right) Function / Signal Limits / Notes
POWER V+, 0V 24 V DC SELV input Reverse / surge protected
VOLTAGE INPUT PE, N, L1, L2, L3 AC sensing (85–265 V AC) Isolated domain
CT INPUT CT1+, CT1–, CT2+, CT2–, CT3+, CT3– External CT (333 mV / 1 V RMS) Shielded pairs recommended
RS-485 A, B, COM Modbus RTU bus Terminate 120 Ω at ends
RELAY 1 NO, C, NC SPDT dry contact 5 A max @ 250 VAC/30 VDC
RELAY 2 NO, C, NC SPDT dry contact 5 A max @ 250 VAC/30 VDC
USB-C D+, D–, VBUS, GND Web Serial / Setup Not for field mount
LED / BTN Interface – Internal header MCU ↔ Field Board Service only

5.5 Reliability & Protection Specifics

5.6 Firmware / Functional Overview

5.7 Mechanical Details


Property Specification
Mounting DIN rail EN 50022 (35 mm)
Material / Finish PC / ABS V-0, matte light gray + smoke panel
Dimensions (L × W × H) 70 × 90.6 × 67.3 mm (9 division units)
Weight ~420 g
Terminals 300 V / 20 A / 26–12 AWG (2.5 mm²) / torque 0.5–0.6 Nm / pitch 5.08 mm
Ingress Protection IP20 (EN 60529)
Operating Temp. 0–40 °C / ≤95 % RH (non-condensing)
Mechanical Dimensions
ENM-223-R1 Physical Dimensions (DIN-rail enclosure)

5.8 Standards & Compliance

Standard / Directive Description
Ingress Rating IP20 (panel mount only)
Altitude Limit ≤ 2000 m
Environment RoHS / REACH compliant

6. Modbus RTU Communication

The ENM‑223‑R1 communicates over RS‑485 (Modbus RTU) and supports:

The device acts as a Modbus Slave and can be polled by a PLC, SCADA, ESPHome, or Home Assistant system.

6.1 Addressing & Protocol Settings

Setting Value
Default Address 3 (configurable: 1–255)
Baud Rate 19200 8N1 (configurable)
Physical Layer RS‑485 (half-duplex, A/B/COM)
Function Codes 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x10
Termination External 120 Ω at bus ends
Fail-safe Bias Required on master side

📌 Use the WebConfig tool over USB‑C to set Modbus address and baud rate.

6.2 Input Registers — Real-Time Telemetry (FC04)

Address Type Metric Unit Scaling
100–102 U16 Voltage L1/L2/L3 V ×0.01
110–112 U16 Current L1/L2/L3 A ×0.001
200–207 S32 Active Power (L1–3, Totals) W 1
210–217 S32 Reactive Power (L1–3, Totals) var 1
220–227 S32 Apparent Power (L1–3, Totals) VA 1
240–243 S16 Power Factor L1–3, Total – ×0.001
244–246 S16 Phase Angle L1–3 ° ×0.1
250 U16 Frequency Hz ×0.01
251 S16 Temperature (internal) °C 1

6.3 Energy Registers (Wh/varh/VAh, FC04)

Address Type Energy Type Phase / Total Unit
300–307 U32 Active Energy (+ import) A/B/C/Totals Wh
308–315 U32 Active Energy (− export) A/B/C/Totals Wh
316–323 U32 Reactive Energy (+ inductive) A/B/C/Totals varh
324–331 U32 Reactive Energy (− capacitive) A/B/C/Totals varh
332–339 U32 Apparent Energy A/B/C/Totals VAh

Energy values are 32-bit unsigned integers (Hi/Lo word pairs).

6.4 Holding Registers — Configuration (FC03/06/16)

Address Type Description Range / Units
400 U16 Sample Interval 10–5000 ms
401 U16 Line Frequency 50 or 60 Hz
402 U16 Sum Mode 0 = algorithmic
1 = absolute
403 U16 Ucal Gain 1–65535
410–420 U16 Ugain A/B/C 16-bit
421–431 S16 Uoffset A/B/C 16-bit
440–450 U16 Igain A/B/C 16-bit
451–461 S16 Ioffset A/B/C 16-bit
499 U16 Factory Reset Trigger Write 1 to reset

6.5 Coils — Output Control (FC01/05/15)

Address Description
600 Relay 1 Control (ON/OFF)
601 Relay 2 Control (ON/OFF)
610–613 Alarm Acknowledgment (L1–L3, Totals)

6.6 Discrete Inputs — Read-only Status (FC02)

Address Description
500–503 LED Status (U.1–U.4)
520–523 Button Press (1–4)
540–541 Relay State (1–2)
560–571 Alarm/Warning/Event flags

6.7 Scaling Summary

Metric Register Type Scale Factor
Voltage (V) Input Register ÷100
Current (A) Input Register ÷1000
Power Factor Input Register ÷1000
Frequency (Hz) Input Register ÷100
Angle (°) Input Register ÷10
Energy (Wh) 32-bit Input 1

6.8 Polling Best Practices

🛠 To reduce bus collisions, stagger multiple ENMs on a shared RS‑485 bus using different poll intervals and address spacing.

6.9 Modbus Integration Example (MiniPLC)

modbus_controller:
  - id: enm223
    address: 3
    modbus_id: rtu_bus
    update_interval: 1s

sensor:
  - platform: modbus_controller
    modbus_controller_id: enm223
    name: "Urms L1"
    register_type: read
    address: 100
    value_type: U_WORD
    unit_of_measurement: "V"
    accuracy_decimals: 2
    filters:
      - multiply: 0.01

switch:
  - platform: modbus_controller
    modbus_controller_id: enm223
    name: "Relay 1"
    register_type: coil
    address: 600

7. ESPHome Integration Guide (MicroPLC/MiniPLC + ENM‑223‑R1)

The HomeMaster controller (MiniPLC or MicroPLC) running ESPHome acts as the Modbus RTU master over RS‑485. It polls one or more ENM‑223‑R1 modules and publishes all sensors, relays, LEDs, and alarms into Home Assistant.

No Home Assistant add-ons are required — all logic runs on the ESPHome controller.

7.1 Architecture & Data Flow

LED mappings, alarm logic, and override behavior are configured on the ENM module (via WebConfig). Home Assistant only reacts to exposed states.

7.2 Prerequisites (Power, Bus, I/O)

1. Power

2. RS‑485 Bus

3. Field I/O

7.3 ESPHome Minimal Config (Enable Modbus + Import ENM Package)

uart:
  id: uart1
  tx_pin: 17
  rx_pin: 16
  baud_rate: 19200
  stop_bits: 1

modbus:
  id: rtu_bus
  uart_id: uart1

modbus_controller:
  - id: enm223_1
    address: 4
    modbus_id: rtu_bus
    update_interval: 1s

packages:
  enm223_1:
    url: https://github.com/isystemsautomation/homemaster-dev
    ref: main
    files:
      - path: ENM-223-R1/Firmware/default_enm_223_r1_plc.yaml
        vars:
          enm_id: enm223_1
          enm_address: 4
          enm_prefix: "ENM #1"

7.4 Entities Exposed by the Package

Binary Sensors

Sensors

Switches

Numbers (Optional)

7.6 Using Your MiniPLC YAML with ENM

  1. Keep existing uart: and modbus: blocks
  2. Add the packages: block (as shown) and set enm_address from WebConfig
  3. Flash the controller — ESPHome discovers all sensors/entities automatically
  4. Add HA dashboard cards and switches for relay, override, and ack actions

7.7 Home Assistant Setup & Automations

8. Programming & Customization

8.1 Supported Languages

8.2 Flashing via USB-C

  1. Connect USB-C to your PC.
  2. Enter boot/flash mode if required.
  3. Upload the provided firmware/source.

Boot/Reset combinations:

These combinations are handled in hardware. Use them when flashing or manually rebooting the module.

🧭 Button layout reference:

Button layout

8.3 Arduino IDE Setup

#include <Arduino.h>
#include <SPI.h>
#include <SimpleWebSerial.h>
#include <Arduino_JSON.h>
#include <LittleFS.h>
#include <math.h>
#include <limits>

8.4 Firmware Updates

9. Maintenance & Troubleshooting

Symptom Fix or Explanation
Relay won’t activate May be in override; check relay logic mode
RS-485 not working A/B reversed or un-terminated bus
LED doesn’t light up Reassign in WebConfig or check GPIO18–21
Button unresponsive Test using WebConfig > Button state live
CRC Errors Confirm baud, address, and wiring (A/B swap)
Negative Power Reading Flip CT or check phase/CT alignment

10. Open Source & Licensing

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.

11. Downloads

The following key project resources are included in this repository:

🔁 Latest releases can also be found in the Releases tab or in the Firmware/ directory.

12. Support

If you need help using or configuring the ENM‑223‑R1 module, the following support options are available:

🛠 Official Resources

📡 Community & Updates