Dimmer esp v1 main

A rotary Zigbee dimmer switch

A Zigbee dimmer switch with a tactile feeling like classic rotary dimmers that seamlessly integrates with your existing switch and socket design lines (e.g. Gira System 55).

Use case, requirements, and features

The goal of this dimmer switch is to

• provide tactile feeling like classic rotary dimmers, i.e. rotate and push one big knob (instead of multiple buttons)
• integrate with existing switch and socket design lines (e.g. Gira System 55), also for multi frames
• offer an optional 230V (or 110V) power supply, no more changing batteries + acts as Zigbee router
• control existing smart lights (e.g. Philips Hue), not making classic bulbs smart (i.e. switching/dimming classic bulbs)

Also nice to have:

• be extendable, e.g. easily add multiple dimmer switches or push buttons in multi frames
• ✅ allow for a second rotary input by rotating the knob while pushing it (e.g. to change color temperature or scenes) — implemented: push + rotate changes color temperature
• ✅ feature an integrated 230V (or 110V) mechanical switch to switch power of the connected lamp socket (e.g. for emergencies or to reset the lamp when replacing classic wall switches) — implemented: on-board relay + dedicated button
• be affordable

Backstory: Why yet another Zigbee dimmer switch?

TL;DR; I couldn't find one to fit my use case, so I decided to build my own.

When I moved into my new home I already had many Philips Hue Bulbs and classic Hue dimmer switches (the on with the four buttons) to control the lights. However, those didn't integrate well with my Gira System 55 outlets, switches, frames, etc. even when using fancy adapters (https://www.samotech.co.uk/products/philips-hue-dimmer-frame-cover-light-switch/) And I was also a big fan of using a rotary knob for dimming lights, since it is just more convenient.

So why didn't I use available rotary zigbee dimmers? Basically all dimmers I found are "real" dimmers, in the sense that they expect to control a load (classic dimmable bulb) or simply don't fit into the 55mm Gira system.

Since I though "well, it can't be that hard to hook up a rotary encoder to a Zigbee chip", I set out to build a rotary dimmer switch myself.

Current state of development

A working second prototype is built around the ESP32-C6. It joins any standard Zigbee coordinator (zigbee2mqtt, Home Assistant ZHA, deCONZ, …) as a mains-powered Zigbee router and controls bound smart lights with a single rotary knob. Hardware, firmware, and enclosure design files are all in this repository. It is a DIY prototype, not a finished product — see Help wanted.

Hardware

• ESP32-C6-MINI module (Zigbee/Thread radio), programmed/powered over USB-C.
• Integrated 230V → 5V power supply (IRM-02-5S) plus a 3.3V regulator — no batteries, and it acts as a Zigbee router.
• Rotary encoder with push (the single "big knob") for dimming and on/off.
• WS2812B RGB LED for status/feedback.
• On-board 230V relay (on a normally-closed contact) to switch the connected lamp socket directly, with a dedicated button to toggle it.
• A separate commissioning button for pairing / factory reset.
• Two external daughterboard ports so the in-wall module can drive a second control surface: a port for an external rotary encoder (a second dimmer) and a port for a plain wall switch. Both are optional — when nothing is wired in they idle and stay unused.
• Designed to fit Gira System 55 frames.

Controls

LED feedback: green = joined · solid red = not connected · white blink = command sent · red blink = command dropped (not joined) · blue blink = relay toggled · yellow = pairing / reset warning.

Firmware

Built with ESP-IDF and the esp-zigbee-sdk. From firmware/:

idf.py set-target esp32c6
idf.py build
idf.py -p <PORT> flash monitor

After the first flash, firmware updates are delivered over the air (standard Zigbee OTA, with automatic rollback of a bad image). The single source of truth for the version is firmware/main/version.h.

Repository layout

• hardware/ — KiCad schematics, PCB, and exported gerbers/3D models.
• firmware/ — ESP-IDF project (firmware/docs/OTA.md, firmware/z2m/README.md, firmware/TODO.md).
• enclosure/ — printable enclosure / knob design files.

zigbee2mqtt integration & over-the-air updates

The dimmer joins any standard Zigbee coordinator and exposes four endpoints: the on-board controller (endpoint 1) that sends on/off, brightness and color commands to bound lights, the on-board 230V relay (endpoint 2) to switch the connected lamp socket directly, and the two optional daughterboard ports — an external encoder (endpoint 3, a second dimmer) and an external wall switch (endpoint 4). Each controller endpoint is bound independently, so they act as separate controllers sharing one device card. It also implements the standard Zigbee OTA Upgrade cluster, so firmware updates are delivered over the air. To add the device to zigbee2mqtt and receive OTA updates from this repo, follow firmware/z2m/README.md. Firmware-side OTA details (partitioning, rollback) are in firmware/docs/OTA.md.

Help wanted

My prototype is working but I see a lot of potential for improvement. Since I am mostly a software engineer with limited knowledge of electronics, I am looking for other interested in taking this project further. You can find me on discord here: https://discord.gg/CjbDc5nPja or checkout the discussion here: https://community.home-assistant.io/t/diy-zigbee-rotary-wall-dimmer/681751