> For the complete documentation index, see [llms.txt](https://docs.smart-stuff.nl/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.smart-stuff.nl/p1-modbus-dongle/firmware-v2-existing-installations/release-notes.md).

# Release notes

Release history for firmware v3, firmware v2 and legacy firmware v1 of Smart Meter Modbus RTU adapters.

## Firmware v3 — all Modbus RTU adapters

### 3.0.1

* Expanded the custom mapper to up to 80 register entries and 1024 bytes per mapping.
* Added signed phase and total currents by direction in custom mappings.
* Added the choice to return zero or a Modbus error for registers not included in a custom mapping.
* Added verified Smartstuff starter mappings, including SDM630 and P1M floats.
* Improved P1M float phase-current handling.

### 3.0.0

* Added the Custom mapping expert feature for systems that do not match a supplied Modbus profile.
* Added persistent storage of one custom mapping on the adapter.
* Introduced the internal energy-data model used by the Modbus mappings, while retaining the established standard mapping behaviour.

## Firmware v2

Firmware v2 release notes apply to supported Smart Meter Modbus Adapter hardware unless an item names a specific variant.

### 2.3.0 — 24 June 2026

* Added firmware updating directly from the Device Manager.
* Added stable-version checking and update notifications.
* Added a Modbus RTU request monitor.
* Added Device Manager and RGB LED warnings when the RS485 module is missing.
* Updated the ESP32 Arduino SDK to 3.3.10.

### 2.2.3 — 24 June 2026

* Added the SunSpec model 203 mapping.

### 2.2.2 — 24 June 2026

* Added EM111 emulation.
* Corrected word order handling for EM330 and EM111 mappings.

### 2.2.1 — 3 May 2026

* Synchronised Modbus mappings with the DSMR-API implementation.
* Refactored the mapping definitions for lower overhead and easier maintenance.

### 2.2.0 — 2 May 2026

* Restored the standard defaults: Default P1 mapping, device ID `43`, `38400 8E1`.
* Added the P1MB / Wallbox mapping.
* Set the default D1MC RGB LED brightness to 10%.

### 2.1.1 — 26 April 2026

* Added configurable RGB LED brightness.
* Corrected P1 output mapping and the NRGD P1 output LED behaviour.

### 2.1.0 — 25 April 2026

* Added selectable P1 and HAN smart meter sources on compatible hardware.
* Expanded persistent configuration and Device Manager controls.
* Added the current RGB status LED behaviour and factory-reset flow.

### 2.0.1 beta — 12 April 2026

* First public beta of the unified firmware v2 architecture.
* Introduced runtime-selectable Modbus mapping profiles.

## Firmware v1

### 1.5.10

* Final v1 maintenance release.
* Recompiled with updated DSMR parsing to accept current values from Kenter meters.

Earlier v1 releases used separate firmware variants for mappings and communication defaults. They remain available for existing installations through the web installer.